Jong Min Choi

Hanbat National University, Daiden, Daejeon, South Korea

Are you Jong Min Choi?

Claim your profile

Publications (45)68.91 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: An advanced optical activation of neural tissues is demonstrated using pulsed infrared light and plasmonic gold nanorods. Photothermal effect localized in plasma membrane triggers action potentials of in vivo neural tissues. Compared with conventional infrared stimulation, the suggested method can increase a neural responsivity and lower a threshold stimulation level significantly, thereby reducing a requisite radiant exposure and the concern of tissue damage.
    Small 06/2014; · 7.82 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, we investigated the performance improvement of a localized surface plasmon resonance (LSPR) biosensor by incorporating a metal-dielectric-metal (MDM) stack structure and subwavelength metallic nanograting. The numerical results showed that the LSPR substrate with a MDM stack can provide not only a better sensitivity by more than five times but also a notably improved signal quality. While the gold nanogratings on a gold film inevitably lead to a broad and shallow reflectance curve, the presence of a MDM stack can prevent propagating surface plasmons from interference by locally enhanced fields excited at the gold nanogratings, finally resulting in a strong and deep absorption band at resonance. Therefore, the proposed LSPR structure could potentially open a new possibility of enhanced detection for monitoring biomolecular interactions of very low molecular weights.
    Applied Optics 04/2014; 53(10):2152-2157. · 1.69 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We demonstrate the proof-of-concept for developing a multi-color fluorescence imaging system based on plasmonic wavelength selection and double illumination by white light source. This technique is associated with fluorescence excitation by transmitted light via a diffraction of propagating surface plasmons. Since double illumination through both sides of isosceles triangle prism in the Kretschmann configuration enables multiple transmission beams of different wavelengths to interact with the specimen, our approach can be an alternative to conventional fluorescence detection owing to alignment stability and functional expandability. After fabricating a plasmonic wavelength splitter and integrating it with microscopic imaging system, we successfully confirm the performance by visualizing in vitro neuron cells labeled with green and red fluorescence dyes. The suggested method has a potential that it could be combined with plasmonic biosensor scheme to realize a multi-functional platform which allows imaging and sensing of biological samples at the same time.
    Optics Express 03/2014; 22(5):5977-85. · 3.55 Impact Factor
  • Honghyun Cho, Jong Min Choi
    [Show abstract] [Hide abstract]
    ABSTRACT: The main solution for the reduction of energy consumption in the field of HVAC is the development of new and renewable energy technologies. Among the various renewable energy systems, ground source heat pump (GSHP) systems have been spotlighted as efficient building energy systems because of their great potentials for energy reduction in building air conditioning and reducing CO2 emissions. However, higher initial cost works as a barrier to the promotion of their use. Therefore, it is critical to reduce the initial costs by optimizing the design of the system. In this paper, parameters that affect the performance of the GSHP system and the size of ground loop heat exchanger (GLHX) have been investigated. Ratio of GLHX length to unit capacity (L/Q) decreased according to increasing value of thermal conductivity, but L/Q increased according to increasing value of borehole heat transfer resistance. In cooling mode, L/Q decreased according to increasing EWT of underground circulating water and borehole distance but increased in heating mode. The value of L/Q tended to increase according to increasing underground initial temperature in cooling mode, but decreased in heating mode. L/Q decreased according to increasing U-tube separation distance and decreasing underground circulating water flow rate, because the thermal interference effect of underground circulating water and heat absorption and emission rate from the ground decreased. The reduction of the size of GLHX is very important in the aspect of saving total installation cost of a GSHP system. Therefore, the size of GLHX and the performance of GSHP system should be considered together for optimum design of the GSHP system.
    Renewable Energy. 01/2014; 65:2–6.
  • [Show abstract] [Hide abstract]
    ABSTRACT: We aimed to develop a cell culture model of type 2 diabetes by treating SK-Hep-1 cells with four free fatty acids [i.e., palmitic acid, stearic acid (SA), linoleic acid and oleic acid]. The results showed that Akt phosphorylation was increased in SK-Hep-1 cells treated with insulin in a time- and concentration-dependent manner, which was inhibited by saturated fatty acids, but not by unsaturated fatty acids. Moreover, protein levels of NADPH oxidase (NOX) 4 but not NOX2 were increased following SA treatment and, consequently, increased reactive oxygen species production and decreased cellular glutathione were observed. Apocynin, a NOX4 inhibitor, restored the SA-induced inhibition of Akt phosphorylation, suggesting the role of NOX4 in insulin resistance induced by SA. Neither phosphorylation level nor protein level of the stress signaling kinases, such as c-Jun N-terminal kinase or p38 mitogen activated protein kinase, was changed by SA treatment. Although binding immunoglobulin protein, a marker of endoplasmic reticulum stress, was transiently increased in SKHep-1 cells treated with SA, 4-phenyl butyric acid, a chemical chaperone, had no effect on the insulinmediated Akt phosphorylation inhibited by SA. The present study provides a useful model for screening anti-insulin resistance drugs and finding new drug targets for treatment of diabetes.
    Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 11/2013; · 2.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sepsis, a systemic inflammatory response syndrome, remains a potentially lethal condition. (S)-1-α-Naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (CKD712) is noted as a drug candidate for sepsis. Many studies have demonstrated its significant anti-inflammatory effects. Here we first examined whether CKD712 inhibits lipopolysaccharide (LPS)-induced arachidonic acid (AA) release in the RAW 264.7 mouse monocyte cell line, and subsequently, its inhibitory mechanisms. CKD712 reversed LPS-associated morphological changes in the RAW 264.7 cells, and inhibited LPS-induced release of AA in a concentrationdependent manner. The inhibition was apparently due to the diminished expression of a cytosolic form of phospholipase A2 (cPLA2) by CKD712, resulting from reduced NF-κB activation. Furthermore, CKD712 inhibited the activation of ERK1/2 and SAP/JNK, but not of p38 MAPK. CKD712 had no effect on the activity or phosphorylation of cPLA2 and on calcium influx. Our results collectively suggest that CKD712 inhibits LPS-induced AA release through the inhibition of a MAPKs/NF-κB pathway leading to reduced cPLA2 expression in RAW 264.7 cells.
    Molecules and Cells 11/2013; 36(5):400-9. · 2.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A simple and fast methodology to detect and identify multiple classes of lipid from human plasma is developed utilizing ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF) as lipidomics platform. All the conditions for the sample preparation and analytical instruments were optimized in detail to detect nine lipid classes (phosphatidylserine (PS), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), triacylglyceride (TG), phosphatidylinositol (PI), lysophosphatidylcholine (LysoPC), lysophosphatidic acid (LysoPA), and sphingomyelin (SM)), which are the most important biologically active lipids but have different characteristics. Finally, the plasma was prepared after a liquid-liquid extraction with a mixture of chloroform/methanol (1:2v/v) including salting out by adding 0.15M of NaCl and the residue after evaporation was reconstituted with a mixture of chloroform/methanol (1:1v/v) to dissolve all lipids which have different polarity. The chromatographic conditions were set up such that mobile phase (A) comprised 10mM ammonium acetate in 40% acetonitrile and mobile phase (B) comprised 10mM ammonium acetate in acetonitrile:isopropanol=10:90(v/v) with ACQUITY BEH C18 as the stationary phase. In particular, a retention time index of PC was constructed by analyzing known standards to confirm each variant of PC without the use of any additional standards in every experiment. The lipidomic methodology and the retention time index of PC were applied to analyze the lipidomic profiling of human plasma from rosuvastatin (lipid lowering drug) treated subjects. In the developed lipidomic platform, all lipids were successfully analyzed within 16min and PCs could be confirmed with the PC retention time index. In rosuvastatin treatment, the lipid profiling was changed in all the eight lipid classes. The level of SM, TG, PI and PE decrease significantly but LysoPCs and PCs were whether decreased or increased. Those results indicated that the plasma level of overall lipids decreased by drug response, however, the changes in the lipids which are important components for biological membrane such as LysoPC and PC were more complicated, and it could be related to the side effect of rousuvastatin. In conclusion, it was found that our lipidomic methodology and the PC retention time index provided not only overall lipidomic information but also profiled specific information of drug response.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 10/2013; 944C:157-165. · 2.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Lipoma arborescens (LA) is a rare benign lesion of unknown etiology. It is characterized histologically by villous proliferation of the synovial membrane and diffuse replacement of the subsynovial tissue by mature fat cells. This condition affects the knee joint most commonly. Cases involving other locations including glenohumeral joint,[1] hip,[2] elbow,[3] hand[4] and ankle[5] have been rarely described. Involvement of the subdeltoid bursa has also been reported, but to date no case has described LA with osseous/chondroid differentiation of this bursa. Another significant finding in our case was the coexistence of LA with intermuscular lipoma, SLAP lesion and labral cyst.
    International Journal of Shoulder Surgery 07/2013; 7(3):116-9.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Granulocyte-macrophage colony-stimulating factor (GM-CSF) is an important regulator of the maturation and function of cells in the granulocyte and macrophage lineages, and also plays a significant role in wound healing. In a previous study, we expressed human GM-CSF in rice cells (rice cell-derived human GM-CSF; rhGM-CSF). The purpose of the present study was to evaluate its effect on wound healing in oral mucositis. Oral mucositis was induced in Syrian hamster cheek pouches by 5-fluorouracil treatment and mechanical scratching. Ulcerated areas were treated from days 3 to 14 with an application of 200 µL saline, or of the same volume of a solution containing 0.04, 0.2, or 1 µg/mL rhGM-CSF. Treatment of hamsters with rhGM-CSF reduced the ulcerated areas of the oral mucosa, compared with the control. Early in the healing process, the mucositis tissue layer of the rhGM-CSF-treated group showed significantly decreased myeloperoxidase activity and increased numbers of proliferating cell nuclear antigen (PCNA)-positive cells. Treatment with rhGM-CSF also affected expression of inflammatory cytokines in the ulcerative mucosal tissue. These results demonstrate the efficacy of plant-produced rhGM-CSF in wound healing and have significant implications for the development of rhGM-CSF as a therapeutic agent for ulcerative oral mucositis.
    Biological & Pharmaceutical Bulletin 01/2013; 36(3):425-31. · 1.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 1. The interactions between herbal dietary supplements and therapeutic drugs have emerged as an important issue and P-glycoprotein (P-gp) has been reported as one of the significant factors of these interactions. 2. The objective of this article is to examine the effects of single and repeated administrations of silymarin on pharmacokinetics of a P-gp substrate, risperidone, and its major metabolite, 9-hydroxyrisperidone, in rats. 3. To determine the plasma levels of risperidone and 9-hydroxyrisperidone in rats, a HPLC method was developed using a liquid-liquid acid back extraction. When risperidone (6 mg/kg) was co-administered with silymarin (40 mg/kg) to rats orally, the C(max) of 9-hydroxyrisperidone was significantly increased to1.3-fold (p < 0.05), while the other pharmacokinetic parameters did not show any significant differences. Expanding the experiment where rats were repeatedly administered with silymarin for 5 days prior to giving risperidone, the C(max) of risperidone and 9-hydroxyrisperidone were significantly increased to 2.4-fold (p < 0.001) and 1.7-fold (p < 0.001), respectively, and the AUC(0-t), as well to 1.7-fold (p < 0.05) and 2.1-fold (p < 0.01), respectively. 4. The repeated exposures of silymarin, compared to single administration of silymarin, increased oral bioavailability and affected the pharmacokinetics of risperidone and 9-hydroxyrisperidone, by inhibiting P-gp.
    Xenobiotica 12/2012; · 1.98 Impact Factor
  • Kojo Atta Aikins, Jong Min Choi
    [Show abstract] [Hide abstract]
    ABSTRACT: Heat pumps, as a process recirculating environmental heat back into useful heat production, fit the environmental requirements of present global policy. They are very useful tools to reduce the need of fossil fuels in space heating and cooling. The government of the Republic of Korea has promoted the distribution of heat pump systems that apply geothermal energy, and has adopted regulation to prevent the use of low efficiency heat pump units. Only heat pump units certified by the government can be used in ground source heat pump (GSHP) systems. Certified heat pump units in the Republic of Korea were analyzed and discussed in this paper. All certified products had cooling capacities less than 280 kW (80 RT). Most of the cooling COPs (Coefficient of Performance)s were found to be superior to heating COPs for GSHP units in the Republic of Korea. To save energy, correspond to environmental regulations and reduce the installation cost of applying GSHP systems, it is suggested that the certification standard concerning underground circulation flow rate should be revised. In addition, there is a need for the revision of the certification standards to include floor heating in order to be able to apply GSHP systems for a variety of purposes.
    Energy 11/2012; 47(1):77–82. · 3.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Non-alcoholic steatohepatitis (NASH) is an increasingly common cause of chronic liver disease; however, no specific pharmacologic therapy has been shown to be effective in its treatment. The present study was designed to develop an experimental cell culture model of NASH using four kinds of fatty acids - palmitic acid (PA), stearic acid (SA), linoleic acid (LA), and oleic acid (OA) - and TNF-α, according to the "two-hit" hypothesis. The saturated fatty acids PA and SA are more cytotoxic than the unsaturated fatty acids OA and LA. Cellular lipid accumulation without cytotoxicity was more easily induced with the unsaturated fatty acids than with the saturated fatty acids. PA augmented TNF-α-induced cytotoxicity, while the unsaturated fatty acids attenuated TNF-α-induced cytotoxicity. In a mechanistic study, PA enhanced TNF-α-mediated apoptosis in the absence of oxidative stress, as determined by measuring the cellular glutathione and malondialdehyde levels. Moreover, PA inhibited the TNF-α-induced phosphorylation of AKT, but not c-Jun N-terminal kinase, indicating that inhibition of survival signaling pathways activated by TNF-α may explain the effects of PA on TNF-α-induced cytotoxicity. The in vitro NASH model established in this study may be used to screen drug candidates for suitability for the treatment of NASH.
    Toxicology in Vitro 06/2012; 26(6):783-90. · 2.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although hepatic expression of cytochrome P450 (CYP) changes markedly in diabetes, the role of ketone bodies in the regulation of CYP in diabetes is controversial. The present study was performed to determine the expression and activity of CYP in non-obese type II diabetic Goto-Kakizaki (GK) rats with normal levels of ketone bodies. In the present study, basal serum glucose levels increased 1.95-fold in GK rats, but acetoacetate and β-hydroxybutyrate levels were not significantly different. Hepatic expression of CYP reductase and CYP3A2 was up-regulated in the GK rats, and consequently, activities of CYP reductase and midazolam 4-hydroxylase, mainly catalyzed by CYP3A2, increased. In contrast, hepatic expression of CYP1A2 and CYP3A1 was down-regulated and the activities of 7-ethoxyresorufin-O-deethylase and 7-methoxyresorufin-O-demethylase, mainly catalyzed by CYP1A, also decreased in GK rats. Hepatic levels of microsomal protein and total CYP and hepatic expression of cytochrome b(5), CYP1B1, CYP2B1 and CYP2C11 were not significantly different between the GK rats and normal Wistar rats. Moreover, the expression and activity of CYP2E1, reported to be up-regulated in diabetes with hyperketonemia, were not significantly different between GK rats and control rats, suggesting that elevation of ketone bodies plays a critical role in the up-regulation of hepatic CYP2E1 in diabetic rats. Our results showed that the expression of hepatic CYP is regulated in an isoform-specific manner. The present results also show that the GK rat is a useful animal model for the pathophysiological study of non-obese type II diabetes with normal ketone body levels.
    Chemico-biological interactions 02/2012; 195(3):173-9. · 2.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aging is associated with immune dysfunction and conditions such as inflamm-aging and immunosuppression. Arsenic, an environmental contaminant distributed worldwide, affects the immune system. This study tested the hypothesis that arsenic has distinct effects on T cell proliferation and the production of cytokines by activated T cells. Murine splenocytes from young (2 months) and aged (24-26 months) C57BL/6 mice were exposed to arsenite (As(3+)), the most toxic form of inorganic arsenic, and stimulated with concanavalin A (Con A) or anti-CD3 antibody. T cell proliferation decreased significantly in response to Con A and anti-CD3 at subtoxic doses of arsenite in splenocytes from both young and aged mice. Arsenite, added concurrently with Con A or anti-CD3, significantly inhibited the production of interleukin-2 (IL-2), interferon-γ (IFN-γ), and interleukin-4 (IL-4) by splenocytes from young mice and significantly reduced the production of IL-10 by splenocytes from aged mice. In contrast, the production of IL-2 and IL-4 by splenocytes from aged mice was only slightly affected by arsenite. The results show that arsenic exposure reduces the immune response in splenocytes. Moreover, this effect may be influenced by aging.
    Archives of Pharmacal Research 02/2012; 35(2):375-82. · 1.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The effective thermal conductivity of six vertical closed-loop ground heat exchangers (GHEXs), which were installed in a test bed located in Wonju, South Korea, has been experimentally evaluated by performing in-situ thermal response tests (TRTs). To compare the thermal efficiency of the GHEXs in field, various installation conditions are considered such as different grouting materials (cement vs. bentonite), different additives (silica sand vs. graphite) and shapes of the circulating pipe-section (conventional U-loop type vs. 3-pipe type). From the test results, it can be concluded that the cement grout has higher effective thermal conductivity than the bentonite grout by 7.4–10.1%, and the graphite outperforms the silica sand by 6.7–9.1% as a thermally-enhancing additive. In addition, the new 3-pipe type heat exchange pipe that yields less thermal interference between the inlet and outlet pipes shows better thermal performance over the conventional U-loop type heat exchange pipe by 14.1–14.5%. Based on the results from the in-situ thermal response tests, a series of cost analyses has been carried out to show the applicability of the cement grouting, the graphite additive, and the new 3-pipe type of heat exchange pipe section. For the same condition, the cement grouting can reduce the construction cost of GHEXs by around 40% in the given cost analysis scenario. In addition, an addition of graphite and use the new 3-pipe heat exchange pipe lead to about 8% and 6% cost reduction, respectively.
    Renewable Energy. 01/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Docetaxel micelle-encapsulated by a tripodal cyclotriphosphazene amphiphilile [NP(PEG750)(GlyPheLeu)(2)Et](3) (CP750) exhibited outstanding drug-loaded micelle stability in aqueous solution compared with the polymeric micelles assembled from linear block copolymers. Furthermore, docetaxel micelle-encapsulated by CP750 is obtainable in solvent free powder form, which is immediately soluble in any aqueous media including saline and PBS and very stable to photo-degradation even in the room light at room temperature. Although docetaxel micelle-encapsulated by CP750 did not display highly improved pharmacokinetic profile compared with Taxotere currently in clinical use, its in vivo xenograft trials exhibited excellent antitumor efficacy by showing complete tumor regression against the breast cancer cells (MDA-MB-231) at a lower dose of 5mg/kg and better efficacy against gastric cancer cells (MKN-28) compared with Taxotere. Furthermore, according to the comparative acute toxicity study, toxicities associated with Taxotere may be remarkably reduced by micelle-encapsulation of docetaxel using CP750, which afforded a much higher LD(50) value of 75 mg/kg compared with 28 mg/kg of docetaxel in Taxotere. Thus docetaxel micelle-encapsulated by CP750 has entered the stage of preclinical studies.
    International Journal of Pharmaceutics 11/2011; 422(1-2):374-80. · 3.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ceramide has been suggested to be not only a tumor-suppressive lipid but also a regulator of phagocytosis. We examined whether exogenous cell-permeable C(6)-ceramide enhances the phagocytic activity of Kupffer cells (KCs) and affects the level of cellular ceramides. Rat KCs were isolated by collagenase digestion and differential centrifugation, using Percoll system. Phagocytic activity was measured by FACS analysis after incubating KCs with fluorescence-conjugated latex beads, and the level of cellular ceramide was analyzed by liquid chromatography tandem-mass spectrometry (LC-MS/MS). In this study we found that permeable C(6)-ceramide increases the cellular levels of endogenous ceramides via a sphingosine-recycling pathway leading to enhanced phagocytosis by KCs.
    Molecules and Cells 08/2011; 32(4):325-31. · 2.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sphingomyelinase catalyzes the hydrolysis of sphingomyelin to generate ceramide, an important molecule involved in the regulation of various cellular responses. In this study, we partially purified the neutral sphingomyelinase2 (nSMase2) and identified the inhibitors, D-lyxophytosphingosine and D-arabino-phytosphingosine, which have an inhibitory effect on nSMase2 in a concentration-dependent manner. A Dixon plot of each phytosphingosines revealed their probable inhibitory pattern, i.e., apparent competitive inhibition. These compounds did not inhibit the Mg(2+)-independent neutral SMase activity, although the known nSMase2 inhibitor, GW4869, showed inhibitory effects on Mg(2+)-independent neutral SMase activity. Further, the two phytosphingosines specifically inhibited the ceramide generation regulated by nSMase2.
    Archives of Pharmacal Research 02/2011; 34(2):229-36. · 1.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The applicability of cement grout (or cement-based grout) has been considered as an alternative to bentonite grout commonly used to backfill closed-loop vertical ground heat exchangers. In a geothermal heat pump system, repeated heating-cooling cycles may cause adverse effects on the integrity of cement grout in the ground heat exchanger. To account for the temperature cycling effect, the strength degradation of cement grout due to temperature cycling has been examined by measuring the unconfined compression strength of cured specimens in a humidity-temperature controlling chamber with applying temperature cycles between −5°C and 50°C. There is a tendency that the unconfined compression strength decreases with an increase in the number of temperature cycles. On the other hand, an equivalent hydraulic conductivity of a pipe-embedded cement grout specimen was evaluated by carrying out a modified flexible wall permeameter test equipped with a water circulating system to control temperature inside the pipe section. The applied operating temperature range was from 5 to 35°C. After three cycles of heating-cooling circulation, the equivalent hydraulic conductivity becomes asymptotic to a constant value, which implies there is no severe detachment of the pipe from the cement grout. Keywordscement grout–bentonite grout–thermal conductivity–workability–equivalent permeability coefficient
    Science China Technological Sciences 01/2011; 54(7):1661-1667. · 1.19 Impact Factor
  • Hangseok Choi, Honghyun Cho, Jong Min Choi
    [Show abstract] [Hide abstract]
    ABSTRACT: To make an energy efficient GSHP system, the heat pump unit should have high efficiency and be optimized well with other parts such as ground heat exchangers and pumps. The amount of refrigerant charge in the heat pump unit is one of the primary parameters influencing system performance. In the present study, the effects of off-design charge on the performance of a ground source heat pump unit are investigated by varying refrigerant charge amount, and the algorithm to predict refrigerant charge amount in the heat pump unit was developed. Undercharge or overcharge of refrigerant into the ground source heat pump unit degraded performance and deteriorated system reliability. Refrigerant flow control by an EEV compensated for refrigerant undercharge or overcharge fault. However, refrigerant charge amount should be detected to optimize the heat pump unit performance. In the first step to develop the algorithm of refrigerant amount detection, the subcooling and superheat at the adjusted EEV conditions are determined as recommended parameters, because they are not sensitive to the EWT of the OD HX. Finally, the subcooling is selected as a fault detection and diagnosis parameter about the refrigerant charge amount in the second screening analysis, because it is properly sensitive to charge amount. The algorithm to predict the refrigerant amount detection in the ground source heat pump unit was developed based on the test data and analysis. The refrigerant amount detection algorithm gave relatively good predictions within a relative deviation of 8.0%.
    Renewable Energy. 01/2011;

Publication Stats

97 Citations
68.91 Total Impact Points


  • 2007–2014
    • Hanbat National University
      • Department of Mechanical Engineering
      Daiden, Daejeon, South Korea
  • 2013
    • Ewha Womans University
      Sŏul, Seoul, South Korea
    • Korea Institute of Science and Technology
      • Molecular Recognition Research Center
      Sŏul, Seoul, South Korea
  • 2009–2013
    • Chung-Ang University
      Sŏul, Seoul, South Korea
  • 2008–2013
    • Chungnam National University
      • • College of Pharmacy
      • • Department of Microbiology
      Sŏngnam, Gyeonggi Province, South Korea
  • 2001–2009
    • Seoul National University
      • Department of Biomedical Engineering
      Seoul, Seoul, South Korea