• Journal of The Korea Institute of Healthcare Architecture
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• v.24 no.3
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• pp.49-57
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• 2018

Purpose: The increase in patients requiring hemodialysis has resulted in an increase dialysis-associated infections risk. but there are no Renal Dialysis unit design standard meet specified safety and quality standards. Therefore, appropriate Establish standards and legal regulation is important for the provision of initial certification and maintenance of facility, equipment, and human resource quality. Methods: Literature survey on the design guideline and standards of Renal Dialysis unit design in Korea, U.S, Germany, Singapore, Hongkong, Dubai. Results: There are no established standards for facilities in dialysis units in Korea. To prevent infections in dialysis patients, necessary establish standards. Considering the domestic and overseas Health-care facilities standards, the major factors to be considered in the medical environment for Renal Dialysis Unit are as follows. First, planning to separate Clean areas(treatment area) from contaminated areas(medical waste storage area). Second, ensure sufficient space and minimum separation distance. Although there may be differences depending on the circumstances of individual institutions, renal dialysis unit consider the space to prevent droplet transmission. Third, secure infrastructure of infection prevention such as sufficient amount of hand hygiene sinks. Hand washing facilities for staff within the Unit should be readily available. Hand hygiene sinks should be located to prevent water from splashing into the treatment area. Fourth, Heating, ventilation and air conditioning (HVAC) system for Renal Dialysis Unit is all about providing a safer environment for patients and staff. Implications: The results of this paper can be the basic data for the design of the Renal Dialysis Units and relevant regulations.

• Journal of Biosystems Engineering
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• v.22 no.1
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• pp.11-20
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• 1997

Thin layer drying tests of short gain rough rice were conducted in an experimental dryer equiped with air conditioning unit. The drying tests were performed in triplicate at three air temperatures of $35^circ$, $45^circ$, $55^circ$, and three relative humidities of 40%, 55%, 70%, respectively. Previously published thin layer equations were reviewed and four different models widely used as thin layer drying equations for cereal grains were selected. The selected four models were Pages, simplified diffusion, Lewis's and Thompson's models. Experimental data were fitted to these equations using stepwise multiple regression analysis. The experimental constants involved in tow equations were represented as a function of temperature and relative humidity of drying air. The results of comparing coefficients of determination and root mean square errors of miosture ratio for low equations showed that Page's and Thompsons models were found to fit adequately to all drying test data with coefficient of determination of 0.99 or better and root mean square error of moisture ratio of 0.025.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.3-8
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• 2005

Building parts of Multi-Family Houses are consisted of several building material assembly. Therefore, after selecting building materials with test result of emission intensity and their feature, composed building materials are made equally with actual construction methods, and experimented emission intensity. 7 days after experiment, formaldehyde emission intensity appeared low in an order of Tile Wall, Wood Flooring, Wallpaper, Reum Flooring, Silk Wallpaper, and 20 days after experiment, TVOC emission intensity appeared low in an order of Tile Wall, Reum Flooring, Silk Wallpaper, Wood Flooring, Wallpaper. There was a clear difference in TVOC emission intensity according to kind of building materials. Composed building materials that weight per unit area is big and omission intensity is high, they effect continuously to indoor air because decrement is small.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.411-416
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• 2006

In this paper, we performed the experimental and numerical study on the thermal comfort(TC) and indoor air quality(IAQ) in the lecture room with a different airflow rate of the ventilation system and heating system for heating season. Through the experimental results, we found out that there was considerably difference of the PMV but there was little difference of $CO_2$ concentration with a different heating system. From a numerical results, the best operating condition was that discharge airflow rate of SAC is 29 CMM and supply airflow rate of the ventilation system is 1,200 CMH from a viewpoint of TC and IAQ.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.4
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• pp.175-185
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• 2018

This research investigates the internal flow and heat transfer in a plate heat exchanger with chevron shape by utilizing the computational fluid dynamics (CFD) software. The basic unit of the plate heat exchanger is generally composed of a hot channel, an intermediate chevron plate, and a cold channel. Several studies have reported experimental and numerical simulation of heat transfer and pressure drop. This study focused on the detailed numerical simulation of flow and heat transfer in the complicated chevron shape channel. The long chevron plate was designed to include 16 chevron patterns. For proper mesh resolution, the number of cells was determined after the grid sensitivity test. The working fluid is water, and its properties are defined as a function of temperature. The Reynolds number ranges from 900 to 9,000 in the simulation. A realizable $k-{\varepsilon}$ model and non-equilibrium wall function are properly considered for the turbulent flow. The friction factors and heat transfer coefficient are validated by comparing them with existing empirical correlations, and other patterned flow phenomena are also investigated.

• Journal of the Korean housing association
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• v.21 no.4
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• pp.23-31
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• 2010

This study aims to examine the educational function space of university dormitories at local universities with corridor centered structure in Honam area regions based on direct and indirect parameters on the whole satisfaction of users in residential environment factors and personal characteristics. First, according to relations among parameters, educational and cultural activities of four major activities within the dormitory had indirect influences on social activities, eating and sleeping activities had no direct influence on other activities. And social activity had direct influence on the general satisfaction as an important parameter and educational and cultural activities had indirect influence on the whole satisfaction through social activities. Detailed results show that, in the first educational activities directly affecting the lighting and air conditioning facilities (0.22), safety (0.326), Territoriality (0.327), the space density (-0.167), directions (-0.166) and yeohyang having personal characteristics and the safety of the second cultural activities (0.183), Territoriality (0.361), Aesthetics (-0.13) and the personal characteristics Sex (-0.179), the direct effect, third, and erosion has a direct impact on activity The flexibility of the space factor (-0.128) and Territoriality (0.38) and the personal characteristics grade (0.172), respectively. Fourth in social activities directly affecting the pathfinding (-0.104), and parameter, education (0.388) and cultural activities (0.445), and some of the factors affecting the indirect lighting and air conditioning facilities, safety, and Territoriality, the space density, directions, grade, they could influence through educational activities to be analyzed. That is, territoriality in educational function space is the important factor that users react very sensitively in educational, eating and sleeping activities and educational function space must secure area and division considering personal and public use as the space accommodating activity which is lacking in unit residential space. Accordingly, the safety of educational function space in university dormitory is considered as the fundamental safety matter on the fire prevention, hygiene and cleanness for users in the satisfaction of educational and cultural activities.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.7
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• pp.492-499
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• 2008

The cooling load in winter is significant in many commercial buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. The development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a multi-heat pump with 3-piping system was investigated as a function of refrigerant charge and its performance was analyzed in cooling mode, heating mode, and heat recovery mode. COP in the heating or cooling mode showed little dependence on refrigerant charge at overcharge conditions, while those were strongly dependent on refrigerant charge at undercharge conditions and outdoor inlet temperature. In the heat recovery mode, the performance of the system was very sensitive to charge amount at all conditions. Optimum charge amount in the heat recovery mode was 14% lower than that in the cooling mode at the standard condition because the refrigerant only passed the indoor units. It is required to store the excessive refrigerant charge in a storage tank to optimize the system performance at operating modes.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.8
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• pp.408-418
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• 2017

Supercritical carbon dioxide ($sCO_2$) power system is emerging technology because of its high cycle efficiency and compactness. Meanwhile, PCHE (Printed Circuit Heat Exchanger) is gaining attention in $sCO_2$ power system technology because PCHE with high pressure-resistance and larger heat transfer surface per unit volume is fundamentally needed. Thermo-fluidic characteristics of $sCO_2$ in the micro channel of PCHE should be investigated. In this study, heat transfer characteristics of $sCO_2$ of various inlet conditions and cross-sectional shapes of single micro channel were investigated experimentally. Experiment was conducted at supercritical state of higher than critical temperature and pressure. Test sections were made of copper and hydraulic diameter was 1 mm. Convective heat transfer coefficients were measured according to each interval of the channel and pressure drop was also measured. Convective heat transfer coefficients from experimental data were compared with existing correlation. In this study, using measured data, a new empirical correlation to predict near critical region heat transfer coefficient is developed and suggested. Test results of single channel will be used for design of PCHE.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.9
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• pp.355-360
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• 2016

Continuing to the modeling of heating load, this paper, as the second part of consecutive works, presents LS-SVM (least square support vector machine) based model of winter time apartment hot water supply load in a district heating system, so as to be used in prediction of heating energy usage. Similar, but more severely, to heating load, hot water supply load varies in highly nonlinear manner. Such nonlinearity makes analytical model of it hardly exist in the literatures. LS-SVM is known as a good modeling tool for the system, especially for the nonlinear system depended by many independent factors. We collect 26,208 data of hot water supply load over a 13-week period in winter time, from 12 heat exchangers in seven different apartments. Then part of the collected data were used to construct LS-SVM based model and the rest of those were used to test the formed model accuracy. In modeling, we first constructed the model of district heating system's hot water supply load, using the unit heating area's hot water supply load of seven apartments. Such model will be used to estimate the total hot water supply load of which the district heating system needs to provide. Then the individual apartment hot water supply load model is also formed, which can be used to predict and to control the energy consumption of the individual apartment. The results obtained show that the total hot water supply load, which will be provided by the district heating system in winter time, can be predicted within 10% in MAPE (mean absolute percentage error). Also the individual apartment models can predict the individual apartment energy consumption for hot water supply load within 10% ~ 20% in MAPE.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.904-909
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• 2009

In this paper, a rolling piston rotary compressor having a combined vane and roller unit has been introduced. In a conventional rotary compressor, sliding motion takes place between the vane nose and roller. By combining the vane and the roller in one unit, gas leakage through a clearance between the vane nose and the roller can be eliminated, and the frictional loss between them can also be reduced to almost nought. Compressor model with the combined vane and roller has been fabricated and tested in a compressor calorimeter and computer simulation program has been developed to confirm merits of the new mechanism. In a test, cooling capacity has been found to be increased by 1.4%, and the compressor input decreased by 0.3%, resulting in 1.7% increased in EER. Simulation program confirmed the calorimeter test results and the merits of the new model as mentioned above.