Ho-Young Lee’s research while affiliated with Yonsei University and other places
What is this page?
This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.
This study investigates the effect of an earlier contract for auditor change (ECAC) on audit quality. In November 2018, the Korean government mandated that client firms must complete audit engagement contracts before the date of the audit report. This requirement informed incumbent auditors about the final year of their engagement prior to completing audit procedures. Our hypothesis suggests that this increased awareness enhances the independence of incumbent auditors, resulting in improved audit quality. The findings support the hypothesis and reveal that audit quality with incumbent auditors in the year preceding the auditor change is higher following the implementation of ECAC. ECAC is identified as a cost‐effective approach, as it can be readily implemented by advancing the notice date for auditor changes. These findings offer valuable insights to other countries seeking to enhance their audit quality while minimising costs.
In a delta connection, most of the battery voltage is applied directly to the motor’s phase terminals, resulting in a voltage that is root three times higher than in a wye connection. This characteristic makes delta connections suitable for low-voltage, high-speed systems. However, the presence of 3n-th harmonic components in the phase back electromotive force (BEMF) of delta-connected motors can induce circulating currents that flow exclusively within the circuit. These circulating currents lead to additional Joule losses and degrade motor performance. This paper analyzes the effect of circulating currents on motor efficiency according to different speeds and torques. The presented study models maintain a similar magnitude of the fundamental component of BEMF, but differ in the magnitude of the 3rd harmonic components. A six-step circuit was established to compare the currents, losses, and efficiencies of the study models using finite element analysis (FEA). The copper losses were categorized into those caused by the fundamental component of phase current and those caused by the circulating currents. Subsequently, the efficiencies of the study models were compared across different speed and torque ranges, accounting for the separated copper loss components and iron losses. The results show that the improved model achieves an efficiency that is more than 18% higher than that of the basic model in the low-speed and low-torque areas. Finally, the study models were manufactured and evaluated through testing.
In this study, a novel fire modeling procedure was proposed for the computational fluid dynamics (CFD) simulation of electrical cable tray fires for improving fire safety in nuclear power plants. The simulation conditions were selected from cable fire experiments that were conducted in open atmosphere and enclosed compartment conditions, as part of the PRISME-3 (French acronym for “Fire Propagation in Elementary Multi-Room Scenarios”) project, an international cooperative project that was carried out under the auspices of the Nuclear Energy Agency (NEA) of OECD. To solve the CFD problem of heat and smoke flow caused by electrical cable fire, we used fire dynamics simulator (FDS) model based on the Naver–Stoke’s equation, which is suitable for low-speed heat flow. In the FDS model, the heat release rate per unit area (HRRPUA), fire duration, and physical properties of the cable were considered as main input parameters and boundary conditions to perform the cable fire simulation analysis. The HRRPUA time curve for cable fires was assumed to be the FLASH-CAT model presented in NUREG-7010. To validate FDS model with the experimental results of cable tray fire scenarios, we compared simulation results by different cable fire models to find a cable fire model that is consistent with the experimental results.
Coronavirus disease-2019 (COVID-19), attributed to the severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2), has posed global health challenges since it first emerged in 2019, and its impact continues to persist. The neurotropic nature of SARS-CoV-2 remains undisclosed, though researchers are proposing hypotheses on how the virus is transmitted to the central nervous system. One of the prevailing hypotheses is that SARS-CoV-2 travels through the olfactory nerve system via the olfactory epithelium (OE). Using a K18-human angiotensin converting-enzyme 2 (hACE2) transgenic mouse model with impaired olfactory sensory neurons (OSNs) induced by zinc sulfate, we examined the role of the olfactory nerve in the brain invasion by SARS-CoV-2. Mice lacking OSNs exhibited reduced levels of viral transmission to the brain, leading to significantly improved outcomes following SARS-CoV-2 infection. Moreover, a positive correlation was observed between viral persistence in the OE and brain infection. These results indicate that early inhibition of the olfactory nerve pathway effectively prevents viral invasion of the brain in K18-hACE2 mice. Our study underscores the significance of the olfactory nerve pathway in the transmission of SARS-CoV-2 to the brain.
Background
Accurate history taking is essential for diagnosis, treatment, and patient care, yet miscommunications and time constraints often lead to incomplete information. Consequently, there has been a pressing need to establish a system whereby the questionnaire is duly completed before the medical appointment, entered into the electronic health record (EHR), and stored in a structured format within a database.
Objective
This study aimed to develop and evaluate a streamlined electronic questionnaire system, BEST-Survey (Bundang Hospital Electronic System for Total Care-Survey), integrated with the EHR, to enhance history taking and data management for patients with pediatric headaches.
Methods
An electronic questionnaire system was developed at Seoul National University Bundang Hospital, allowing patients to complete previsit questionnaires on a tablet PC. The information is automatically integrated into the EHR and stored in a structured database for further analysis. A retrospective analysis compared clinical information acquired from patients aged <18 years visiting the pediatric neurology outpatient clinic for headaches, before and after implementing the BEST-Survey system. The study included 365 patients before and 452 patients after system implementation. Answer rates and positive rates of key headache characteristics were compared between the 2 groups to evaluate the system’s clinical utility.
Results
Implementation of the BEST-Survey system significantly increased the mean data acquisition rate from 54.6% to 99.3% ( P< .001). Essential clinical features such as onset, location, duration, severity, nature, and frequency were obtained in over 98.7% (>446/452) of patients after implementation, compared to from 53.7% (196/365) to 85.2% (311/365) before. The electronic system facilitated comprehensive data collection, enabling detailed analysis of headache characteristics in the patient population. Most patients (280/452, 61.9%) reported headache onset less than 1 year prior, with the temporal region being the most common pain location (261/703, 37.1%). Over half (232/452, 51.3%) experienced headaches lasting less than 2 hours, with nausea and vomiting as the most commonly associated symptoms (231/1036, 22.3%).
Conclusions
The BEST-Survey system markedly improved the completeness and accuracy of essential history items for patients with pediatric headaches. The system also streamlined data extraction and analysis for clinical and research purposes. While the electronic questionnaire cannot replace physician-led history taking, it serves as a valuable adjunctive tool to enhance patient care.
Purpose
This paper aims to examine how the allocation of audit hours to the year-round procedures, based on the risk of material misstatements in financial statements, impacts audit quality.
Design/methodology/approach
Using a data set on audit hours spent on year-round and year-end procedures, the authors build an empirical model for testing the effectiveness of year-round auditing of Korean public firms during the period of 2014–2018.
Findings
The initial tests do not show that proportionate increases in year-round procedures increase audit quality. However, after the authors control for the risk of material misstatements, the authors find that proportionate increases in year-round audit hours generally increase audit quality, except for high-risk firms where audit quality increases only as year-end hours proportionately increase. For high-risk firms, the results suggest that increases in year-round audit procedures occur at the cost of the essential year-end work. Similarly, except for high-risk firms, the authors find that the allocation of more audit effort to year-round procedures improves audit efficiency.
Originality/value
To the best of the authors’ knowledge, this study provides some of the first empirical evidence showing how a risk-based approach to allocating audit effort over the duration of an audit can impact audit quality and efficiency. Regulatory bodies, such as the International Auditing and Assurance Standards Board and Public Company Accounting Oversight Board, which consider the proper allocation of audit hours as a key audit quality indicator, should find the results useful.
Background
The principles of dynamic consent are based on the idea of safeguarding the autonomy of individuals by providing them with personalized options to choose from regarding the sharing and utilization of personal health data. To facilitate the widespread introduction of dynamic consent concepts in practice, individuals must perceive these procedures as useful and easy to use. This study examines the user experience of a dynamic consent-based application, in particular focusing on personalized options, and explores whether this approach may be useful in terms of ensuring the autonomy of data subjects in personal health data usage.
Methods
This study investigated the user experience of MyHealthHub, a dynamic consent-based application, among adults aged 18 years or older living in South Korea. Eight tasks exploring the primary aspects of dynamic consent principles–including providing consent, monitoring consent history, and managing personalized options were provided to participants. Feedback on the experiences of testing MyHealthHub was gathered via multiple-choice and open-ended questionnaire items.
Results
A total of 30 participants provided dynamic consent through the MyHealthHub application. Most participants successfully completed all the provided tasks without assistance and regarded the personalized options favourably. Concerns about the security and reliability of the digital-based consent system were raised, in contrast to positive responses elicited in other aspects, such as perceived usefulness and ease of use.
Conclusions
Dynamic consent is an ethically advantageous approach for the sharing and utilization of personal health data. Personalized options have the potential to serve as pragmatic safeguards for the autonomy of individuals in the sharing and utilization of personal health data. Incorporating the principles of dynamic consent into real-world scenarios requires remaining issues, such as the need for powerful authentication mechanisms that bolster privacy and security, to be addressed. This would enhance the trustworthiness of dynamic consent-based applications while preserving their ethical advantages.
... So far, only limited number studies were able to use mouse models to explore the in-depth mechanisms of long COVID or PASC, including K18-hACE2 with low dose of infection [40][41][42] , AAV-mediated restricted expression of hACE2 in lung 31 , or Balb/c mouse strain 43 . However, the limitations due to rodent's natural resistance has been lifted by the mouse adapted strains. ...
... In addition, although lung samples are easily obtained from infected mice, they are not so readily available from COVID-19 patients. Finally, the plethora of different virus isolates, virus doses, rodent models (including age and gender), and analytical techniques, complicates detailed comparisons across studies [147][148][149][150]. For instance, although RNA-Seq data suggests increased pathogenicity of delta variants over ancestral (original) strain isolates in K18-hACE2 mice [148], numerous methodological differences complicate integration of such data into compelling comparisons with our study. ...
... Depending on whether the authors report or not, the reported items included in full in the collection table were rated "yes". As for the 4 domains, we performed the quality assessment using a 5-point Likert scale, 24 with the narrative quality of the report expressed in descending order from 5 to 1, respectively. If any item was not mentioned at all or the quality of the report was poor, 1 point was awarded. ...
... In addition, although lung samples are easily obtained from infected mice, they are not so readily available from COVID-19 patients. Finally, the plethora of different virus isolates, virus doses, rodent models (including age and gender), and analytical techniques, complicates detailed comparisons across studies [147][148][149][150]. For instance, although RNA-Seq data suggests increased pathogenicity of delta variants over ancestral (original) strain isolates in K18-hACE2 mice [148], numerous methodological differences complicate integration of such data into compelling comparisons with our study. ...
... hPSC-derived mDA neurons hold great promise for cell replacement therapy in PD (3)(4)(5). Indeed, early-stage clinical trials of hPSC-based cell therapy in PD have been initiated in several countries (13)(14)(15)(16)60). To maximize the safety and efficacy of hPSC-based cell therapy approaches, differentiation protocols need to yield high percentages of authentic mDA neurons while minimizing off-target cell types. ...
... The authors subsequently confirmed the antibody's capacity to neutralize wild-type, B.1.617.2, and B.1.1.529 subvariants of SARS-CoV-2 using a lentivirus-based nano-luciferase expressing SARS-CoV-2 pseudoviruses [90]. Gao et al. generated a novel monospecific tetravalent IgG1-(scFv)2 version of mAb 553-15 by fusing two forms of 553-15-derived single-chain variable fragments to the C-terminus of the human immunoglobulin G1 Fc fragment. ...
... User perception of privacy plays a crucial role in the adoption and usability of digital health ecosystems. When patients feel their personal health data is vulnerable, they may be reluctant to use or share information through digital platforms (Lee et al., 2023). ...
... 84-87, 91, 92]. Boosted models were applied 34 times, with XGB used in 21 cases[12,21,28,30,35,42,47,51,53,55,56,60,61,63,65,72,74,77,82,84,86], along with other Boosting algorithms (Boosted DT n = 3[17,24,32], Gradient Boosted DT n = 3[20,68,73], GBM n = 3[43,46,65], Boosted LR n = 2[44,46], CatBoost n = 1[18], AdaBoost (n = 1)[13]. SVM models were used 22 times (most frequently SVM n = 13[12,18 ...
... VACV neutralization targets have been well characterized, frequently including A27 [11], L1R [12], H3L [13], and D8 [14] on MVs, while the effective targets on EVs are relatively fewer, typically confined to A33R and B5R [15][16][17] Combining two or more mAbs may enhance the protective efficacy against VACV infection compared with that seen with the individual mAbs [18,19]. Indeed, many bispecific antibodies (bsAbs), which can simultaneously target the recognition sites of two mAbs, have been developed for diverse viruses, including SARS-CoV-2 [20,21], ebolaviruses [22,23], and dengue virus [24]. ...
... The study indicated that a DSS, that addresses the requirements of medical staff, can be associated with a reduction in falls in care facilities. In contrast, a different result was presented in the publication by Jung et al. [9]. The system in the context of fall prevention was implemented in a medical department and evaluated for ease of use and usefulness in preventing falls. ...