Young-Jin Kim

• Researcher at Kt

This paper presents an inverse model using chaotic behaviour. The chaos time series inverse model, which uses coupling methods between an inverse model and chaos theory can reconstruct a deterministic and low-dimensional phase space by transforming irregular behaviours of nonlinear time-varying systems into a strange attractor (e.g., a Rossler attr...

Recently, a Energy Recovery Ventilator(ERV) in a residential building has been highlighted as an attractive ventilation option in terms of energy saving and Indoor Air Quality(IAQ). For identifying a feasible set among many ventilation strategies in this situation, various decision making approaches(deterministic or stochastic) using building simul...

Monte Carlo simulation (MCS) has been widely used for the uncertainty propagations of building simulation tools. In general, most unknown inputs for the MCS are regarded as single probability distributions based on experts' subjective judgements and assumptions, when simulation information andmeasured data are inaccurate and insufficient. However,...

Building simulation tools have been widely used for performance assessment. However, many studies [1] have reported that a performance gap exists between the reality and simulation output, mainly caused by unknown simulation inputs. Therefore, model calibration needs to be introduced. Calibration attempts can fail for the following reasons: coarse...

Uncertainty Quantification (UQ) employing a Monte Carlo Sampling (MCS) method in a building simulation domain has been widely used to account for risks of predicted outputs for robust decision making. However, the stochastic approach for UQ problems requires significant computational burdens compared to the deterministic approach. This paper addres...

In this paper, the authors present the multi-criterion stochastic optimal selection of a double glazing system for a given office building. Four elements are required for a multi-criterion stochastic optimal design: an accurate and fast simulation model, an optimization solver, correct handling of the multi-criterion decision problem, and considera...

For better energy management of existing buildings, an accurate and fast prediction model is required. For this purpose, this study reports the development of a GP (Gaussian Process) model for an AHU fan of the real high-rise office building. The GP Model is a statistical data driven model, and requires far less inputs and demands less computing ti...

With the increasing focus on low energy buildings and the need to develop sustainable built environments, Building Energy Performance Simulation (BEPS) tools have been widely used. However, many issues remain when applying BEPS tools to existing buildings. This paper presents the issues that need to be solved for the application of BEPS tools to an...

For reliable building performance assessment, uncertainty caused by future climate change and future energy retrofit should be taken into account. This paper presents a case study of risk-based decision making driven by future uncertainty sources (climate, energy retrofit) in an existing office building. For the study, the EnergyPlus model was chos...

This study reports the development of a Gaussian Process (GP) model based on BEMS data. The GP model is a data driven model and requires a few dominant inputs. It provides a quick prediction with a far less computation than the whole building simulation tools (e.g. EnergyPlus). The GP model developed in this study is capable of predicting the behav...

This paper addresses an interface from Building Information Model (BIM) to Building Energy Model (BEM). The interface converts an IFC file exported from BIM authoring tools (e.g. Revit, ArchiCAD) to an IDF file (EnergyPlus input file). For seamless data exchange, a set of mapping rules with regard to space boundary, thermal properties of constructi...

A Sobol sensitivity analysis, which has been widely used for rational decision making of energy retrofit alternatives, provides powerful post-processing sensitivity results that enable to quantitatively identify influential and non-influential inputs. It can quantify the impacts of each input as well as impacts caused by all possible interactions b...

Bayesian calibration has been used to transform the prior distributions of unknown inputs inherited in a building energy simulation model into the trustworthy posterior distributions. It obtains the posterior distributions using a joint distribution composed of a likelihood function and prior distributions of unknown inputs in the Bayesian paradigm...

Sensitivity analysis has been widely used for rational decision making of energy retrofit alternatives. A Sobol method is a variance based approach and provides powerful post-processing sensitivity results that enable to quantitatively identify influential and non-influential inputs. It can account for impacts of each input as well as impacts cause...

Bayesian calibration has been used to transform the prior distributions of unknown inputs inherited in a building energy simulation model into the trustworthy posterior distributions. It obtains the posterior distributions using a joint distribution composed of a likelihood function and prior distributions of unknown inputs in the Bayesian paradigm...

Building simulation is widely used for building performance prediction and assessment in the design process. For seamless connections between Building Information Model (BIM) and Building Energy Model (BEM), tremendous research efforts have been invested, especially with emphasis on data sharing and reuse out of BIM. However, what is lacking in the...

This paper addresses an optimal design problem of ERV (Energy Recovery Ventilator) system that seeks for proper sizing and location of supply diffusers/exhaust registers. A typical of a residential unit consisting of three bedrooms, a living room, and a kitchen was selected. The elements in a cost function includes energy use, thermal comfort, and...

This paper addresses optimal design of windows (types of glazing and cavity gas) using BIM, Genetic algorithm and Pareto optimality. For architectural modeling and energy simulation, Revit Architecture and EnergyPlus were selected in this study. In the paper. presented is an automatic file converter, operating in MATLAB GUI (Graphical User Interfac...

For Model-Predictive Control (MPC) to be implemented in real application, data driven inverse models are advantageous since they are easily constructed as well as relatively fast and accurate, compared to first principle based models (simplified calculation [ISO 13790], dynamic simulation [EnergyPlus, ESP-r, TRNSYS, etc.], state space models, etc.)...

BIM (building information model) enables information sharing and reuse for interoperability between prevalent software tools in the AEC (Architecture, Engineering, and Construction) industry. Although a BIM based energy simulation tool can reduce costs and time required for building energy simulation work, no practical interface between CAD tools a...

This paper addresses a multi-criterion optimal design problem under uncertainty for obtaining a high level of robust design decision making during early design process. Building Performance Simulation (BPS) tools have computation capacities for handling dynamic and nonlinear behaviors in reality and integrating an optimization routine for finding a...

With the growing focus on low energy buildings. Building Energy Performance Simulation (BEPS) tools have been widely used. However, many issues remain unsolved in terms of transparency, reproducibility, objectivity and usability of such tools. In the paper, the authors report issues and difficulties that a Simulationist encounter when applying Ener...

This paper addresses development of a simple and quick prediction model based on the Gaussian Stochastic Process (GASP) requiring a far less computation time than dynamic whole Building Performance Simulation (BPS) tools. An emulator, which can be regarded as a surrogate model of BPS c tools, was developed using Gaussian process regression model an...

This paper reports the development of a Gaussian Process (GP) emulator to make an energy efficient operational decision by emulating complex and dynamic physical behavior of a building. The GP emulator demands much less time and effort as well as produces almost identical outputs compared to the whole-building simulation tools such as EnergyPlus. T...

This study presents optimal control strategies of the system using a Generalized Pattern Search and Genetic Algorithm. Then, the aforementioned two approaches are compared to three other optimal control strategies of a double skin façade reported in the literature. To compare control strategies, the lumped simulation model developed in the previous...

This paper addresses optimal architectural design using BIM at the design stage. We present a comparative study of the differences between data-centric and process-driven interoperability approaches during the design phases. The authors will elaborate on two approaches, summarize their consequences, and present a real application of the approach us...

Recently, Building Information Modeling (BIM)-based energy performance simulations have progressed significantly to yield quick energy prediction. However, simulation models must reflect the probabilistic nature of real world situations to make more significant contribution towards rational design decisions. In this study, pros and cons of two diff...

In this paper, eight ventilation strategies in a typical apartment floor plan in Jeju, Korea were studied. In terms of size and floor plan, the chosen building is typical of residential buildings and consists of three bedrooms, a living room, and a kitchen. In this study, uncertainty propagation was introduced to treat the parameters which are not...

This paper addresses the optimal design of residential ventilation systems in an apartment floor plan in Korea. The term "optimal design" refers to the selection of a ventilation method (mechanical, hybrid), type of heat recovery (total, sensible only), outdoor airflow rate, and the optimal sizing and location of supply diffusers/exhaust registers....