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A Study on the Effect of Open and Closed Room Doors on Apartment Ventilation Characteristics (공동주택에서 각 실 문의 개폐에 따른 환기 특성 연구)

  • Choi, Im-Kyoo;Kim, Young-Il;Chung, Kwang-Seop
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.469-474
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    • 2008
  • The objective of this study is to propose basic design guidelines for more effective air ventilation system in apartments. It is well known that ventilation depends on whether the room doors are open or closed as well as people's living patterns. This study considers 84 ㎡-sized apartment which has extended living room without balcony. Ventilation of bathroom and kitchen is not considered. The height of the building, external air pressure and air infiltration through the windows are also neglected. The regulation on indoor air quality made it mandatory that the air change per hour be more than 0.7. Four models are suggested to study the effect of open and closed doors. Models 1 and 3 are open door types and models 2 and 4 are closed door types. The open types have 50 mm hole near the top of the door to substitute exhaust outlet. The ventilation effectiveness was evaluated by 3-dimensional numerical simulation using finite volume method by a commercial software. This work compares air flow, temperature of air, age of air and the efficiency of ventilation of apartments with wooden doors of bedroom 1 and 2, which are open or closed.

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Using Contour Matching for Omnidirectional Camera Calibration (투영곡선의 자동정합을 이용한 전방향 카메라 보정)

  • Hwang, Yong-Ho;Hong, Hyun-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.6
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    • pp.125-132
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    • 2008
  • Omnidirectional camera system with a wide view angle is widely used in surveillance and robotics areas. In general, most of previous studies on estimating a projection model and the extrinsic parameters from the omnidirectional images assume corresponding points previously established among views. This paper presents a novel omnidirectional camera calibration based on automatic contour matching. In the first place, we estimate the initial parameters including translation and rotations by using the epipolar constraint from the matched feature points. After choosing the interested points adjacent to more than two contours, we establish a precise correspondence among the connected contours by using the initial parameters and the active matching windows. The extrinsic parameters of the omnidirectional camera are estimated minimizing the angular errors of the epipolar plane of endpoints and the inverse projected 3D vectors. Experimental results on synthetic and real images demonstrate that the proposed algorithm obtains more precise camera parameters than the previous method.

HACCP Performance of Employees in School Foodservice Operations and the Related Variables

  • Kim, Mi-Kyeong;Park, Jyung-Rewng;Cha, Myeong-Hwa
    • Preventive Nutrition and Food Science
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    • v.10 no.4
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    • pp.357-363
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    • 2005
  • The purpose of this study was to assess current food-handling practices of employees in school food service settings, as well as their knowledge levels, and identify relationships between knowledge, practices, and influencing variables. The survey was conducted for dietitians and employees in the school foodservice industry in Gyeongsangbuk-do province. A total of 270 and 570 questionnaires for dietitians and employees, respectively, were distributed by mail. Response rates were $62\%$ (N=171) and $66\%$ (N=376) from dietitians and employees, respectively. Data was analyzed using SPSS Windows (version 10.0). Descriptive statistics were used to summarize data. Pearson correlations were applied to test for relationships between knowledge and practice of HACCP principles. Stepwise regression analysis was performed to examine the influence of knowledge, current education guidelines, demographic information (working experience, academic background, and certification for food and cooking), and school characteristics (food production system, service style, and number of meals). School foodservice employees were found to have a significant amount of food safety knowledge ($67.5\pm1.8$ out of 100 possible points). Proper food handling practices were not always being followed in many schools. The relationship between their knowledge, current HACCP education training, and food handling practices was not significant. These results suggested the present situation of HACCP trainings performed by dietitians were inadequate for many school foodservice operations. The number of meals in school was an independent predictor of the employees' food-handling practices. These results suggest that an effective education program should integrate endeavors that take account of social and environmental influences on food safety to support the improvement of food-handling practices and the implementation of a HACCP program. Furthermore, dietitians should continue to provide consulting, training, and technical assistance to schools on HACCP implementation.

The Life Cycle Cost Optimization Methodology as a Tool for Designing Apartment Units (공동주택 단위세대의 생애 비용 최적화 방법론 연구)

  • Park Tae Keun
    • Korean Journal of Construction Engineering and Management
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    • v.1 no.1 s.1
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    • pp.80-86
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    • 2000
  • The future costs of energy and the cost of the repair of apartment buildings are expected to rise continuously in proportion to the initial costs. Therefore it has become important for these increasing costs to be incorporated and reflected in the design of the building. Systems such as structure and services for the buildings remain constant, but a number of the walls and windows can vary and thus have a major influence on the total construction and running costs of a building. The critical factor in the apartment unit design for the optimization of life cycle cost (LCC) is the ratio of the x and y axis of the walls in the unit plan. This paper demonstrates how to achieve the optimal size and thus optimize the LCC of the building.

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Planning of Apartment Units for Improving Natural Ventilation Performance based on the Analysis of Indoor Pollutant Concentrations (오염농도 분포 해석을 통한 공동주택의 자연환기성능 향상을 위한 평면계획)

  • Kim, Jiyoeng;Lee, Seung-Hee;Kim, Taeyeon
    • KIEAE Journal
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    • v.5 no.3
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    • pp.41-48
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    • 2005
  • Before occupation of an apartment housing, the builders are required to inform the test result of IAQ to the public. However, there is no simplified method to predict IAQ before measurement of pollutant concentration. In this study, a simplified way of predicting IAQ based on the distribution of indoor pollutant concentration is proposed. 7 different cases of air change rate have been simulated through CFD analysis to get the distribution ratio of each pollutant material and then simplified functions were used with CRIAQ1 values derived from CFD simulation to evaluate by comparing the influence of each material in the indoor pollutant concentration. Again, a lot of efforts which can improve the indoor air quality have been performed. Materials used in indoor space are labeled with their pollutant emission level. Installation of ventilation system in residential buildings will be regulated by a building codes sooner or later. But it is important to understand the fact that layout of walls, location or size of openings will influence the indoor air flow and pollutant concentration. And location of emitting material influences to indoor air pollutants distribution. But until now there is few recognition and consideration of these factors. Therefore, in this paper the effects of these factors is proved and some kind of guideline is made for designers after a comparison of typical apartment floor plan and a new type plan with their average pollutant concentration and its distribution of each room. CFD(Computational Fluid Dynamics) program was used to show the indoor air flow and pollutant concentration distribution. For this purpose, a typical $100m^2$ apartment floor plan was chosen as a case study model and several alternatives were reviewed to improve the IAQ performance. The simulation took place in the condition of natural ventilation through windows.

A study on the annual energy performance of apartment building with the equivalent U-value of envelope considering the effect of thermal bridges (공동주택 외피의 열교영향을 고려한 상당열관류율 및 연간 에너지소비성능 평가 연구)

  • Kim, Dong Su;Yoon, Jong Ho;Shin, U Cheul;Kwak, Hee Yul
    • KIEAE Journal
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    • v.12 no.3
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    • pp.41-46
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    • 2012
  • The building envelope is important specially for saving energy consumption of residential buildings. but Apartment houses in Korea commonly have inside insulation system which have constantly arisen thermal bridges, the risk of heat loss, as a necessity. This study aims to evaluate integrated insulation performance according to the different shapes of external walls, adjacent to windows. The thermal performance analysis was carried out by Equivalent U-value and using the three-dimensional heat transfer computer simulation (TRISCO-RADCON), under nine different cases of comparing among three each of different bases(current standard model, 30percent energy saving model and 60percent energy saving model). The heating and the cooling load were also compared between two cases (standard U-value and Equivalent U-value) of three each of different bases, using the Building energy simulation which is based on DOE-2.1 analysis. As results, it turns out that if the Equivalent U-value is considered on the envelope analysis, the heat flow loss will be increasing more than the standard U-value, and if heat insulation property of the residential building reinforced rather than current, the rate of influences on the thermal bridges would be extremely expanded. In addition, it is shown that annual heating loads of the apartment house with applied Equivalent U-value substantially increased by more than 15 percent compared to those with the existing U-value, but annual cooling loads were negligibly affected.

A Study on Analysis for Energy Demand of the Heating, Cooling and Lighting in Office Building with Transparent Thin-film a-Si BIPV Window (투광형 박막 BIPV 창호 적용에 따른 냉난방 및 조명 부하 저감에 관한 연구)

  • Yoon, Jong-Ho;An, Young-Sub;Park, Jang-Woo;Kim, Bit-Na
    • KIEAE Journal
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    • v.13 no.3
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    • pp.91-96
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    • 2013
  • The purpose of this study was to analyze the annual energy demand including heating, cooling and lighting according to kind of windows with transparent thin-film a-Si Building Integrated Photovoltaic(a-Si BIPV) for office building. The analysis results of the annual energy demand indicated that the a-si BIPV window was reduced by 8.4% than the clear gazing window. The base model A was combinate with a-Si BIPV window area of 67% and clear window area of 33% among the total exterior area. The model B is to be applied with low-e clear glass instead of clear glass of the base model A. The model B was reduced to annual energy demand of 1% more than the model A. Therefore, By using a-si BIPV solar module, the cooling energy demand can be reduced by 53%(3.4MWh) and the heating energy demand can be increase by 58%(2.4MWh) than clear glazing window in office building. Also, Model C applied to the high efficient lighting device to the model B was reduced to annual energy demand of 14.4% more than the Model D applied to the high efficient lighting device to the model A. The Model E applied with daylight dimming control system to the Model C was reduced to annual energy demand of 5.9% more than Model C.

Perceptions of Residents Visiting Local Health Centers on the Collaborating Care of Korean Traditional Medicine and Western Medicines (양.한방협진에 대한 지역주민의 인식 - 일부 보건소 이용자를 중심으로 -)

  • Yoon, Tae-Hyung;Park, Hae-Mo
    • Journal of Society of Preventive Korean Medicine
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    • v.14 no.1
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    • pp.37-48
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    • 2010
  • Objective : The purpose of this research was to provide basic data for developing the collaborating care of Korean traditional medicine and western medicines by analyzing the perceptions of residents visiting local health centers on the collaborating care. Method : To this end, a self-administrated questionnaire was surveyed to 417 participants from March 10 to March 19, 2005. The questionnaires were regarding medical preferences, effectiveness, co-operative treatment types, and the demographic characteristics of the study population. The main statistical methods employed for analysis were frequency chi-square test analysis, using SPSS system 12.0 software for Windows. Result : First, the perceptions of collaborating care, such as preference and effectiveness, were better for residents who had experienced Korean traditional medicine(p < 0.05). Second, the most favorable collaborating care type was the neuromuscular disease and rehabilitation, and in particular, the preference of the patient who had experienced Korean traditional medicine was much higher than those who had not experienced it(p < 0.05). Third, as for recognizing the future of collaborating care, respondents insisted that collaboration care has to be conducted under evidence-based research. The reasons why collaborating care has not been active were reported as "difference in solving disease problems between oriental medicine and western medicine." The most important role of the Korean traditional medicines in the public sector was to provide specialized service for the elderly and low income households. Conclusion : Most respondents expected the positive effects of the collaborating care and wanted it to develop, particularly for neuromuscular diseases. As for the health promotion program in health centers, it was more popular than the home visiting program for the elderly and preventive rehabilitation for stroke. Now we must plan to balance between the need of the community and the medical provider on collaborating care.

Development of High Speed Scalar Product Operation System for ECC Public Key (타원곡선 공개키 생성을 위한 고속 스칼라곱 연산 시스템 구현)

  • Kim, Kap-Yol;Lee, Chul-Soo;Park, Seok-Cheon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.2
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    • pp.394-402
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    • 2010
  • At a recent, enterprises based on online-service are established because of rapid growth of information network. These enterprises collect personal information and do customer management. If customers use a paid service, company send billing information to customer and customer pay it. Such circulation and management of information is big issue but most companies don't care of information security. Actually, personal information that was managed by largest internal open-market was exposed. For safe customer information management, this paper proposes the method that decrease load of RSA cryptography algorithm that is commonly used for preventing from illegal attack or hacking. The method for decreasing load was designed by Binary NAF Method and it can operates modular Exponentiation rapidly. We implemented modular Exponentiation algorithm using existing Binary Method and Windows Method and compared and evaluated it.

A Study on the Environmental Performance Level Measurement in the Lecture Room during Winter Time (동계 대학강의실 환경성능수준 측정에 관한 연구)

  • Ahn, Tae-Kyung
    • Journal of the Korean Institute of Educational Facilities
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    • v.25 no.2
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    • pp.3-9
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    • 2018
  • This study is designed to measure the indoor environment and research on the environmental situation in the lecture room where the lecture is conducted during the winter time in order to understand the level of environment in the lecture room and then suggest the method of improving the environment in the lecture room in the future. The findings are as follows. First, the number of ventilation measured at Lecture Room 1 was 1.2 times/hour while that at Lecture Room 2 was 2.2 times/hour. Second, the lighting at Lecture Room 1 and 2 was 650~700 lux while the noise at Lecture Room 1 and 2 was not more than 60dB. Third, Group 1 and Group 2 felt in the same way that the air quality in the lecture room was not good when the air quality was measured in 30 minutes after the start of lecture. Fourth, both Group 1 and Group 2 showed the lowered concentration on the class in 30 minutes after the start of the class when the room was heated. But Group 1 got less drop in the concentration when they was put in the non-heated room. Fifth, As for the change in the carbon dioxide volume during lecture, the carbon dioxide volume in the room where the windows was closed rose 1,000~1,400ppm from that at the time of start, thus showing that the indoor air quality got worsened. In addition, it is hard to control the indoor temperature due to the heating and non-heating. Accordingly, it is necessary to get the heating system which can make the ventilation in order to keep the environmental level in the lecture room to a certain level and keep the proper indoor temperature.