• KIEAE Journal
• /
• 제5권1호
• /
• pp.11-18
• /
• 2005

The optimized HVAC system design in tall buildings enable owners to save unnecessary energy consumption and residents to have comfort environments. The purpose of this study is to develop design process for optimized HVAC system design in tall buildings. As basic researches, literature researches and case studies of HVAC system design in tall buildings were performed. Survey was processed among expert in the field and key considerations on HVAC system design were drew as conclusions. With these conclusions, studies were performed on effects of wind velocity, outdoor air temperature, and solar radiation that are main factors of load calculation in tall buildings. Finally, air-tightness and stack effect were analyzed and estimated by literature studies, field measurements and computer simulations.

• KIEAE Journal
• /
• 제10권4호
• /
• pp.117-122
• /
• 2010

In these days numerous super tall buildings are under construction or being planned in Middle East and Asian countries. Some of them are planned as an ultra high-rise building that goes over 600m tall, including Burj Khalifa, the tallest building in the world. External environment such as wind speed, temperature and humidity of the super tall building varies due to its vertical height. Therefore, it is necessary to consider these environmental changes to estimate building heating and cooling load. This paper analyzes how vertical microclimate difference affects building heating and cooling load in super tall building by simulation using radiosonde climate data. Besides, the correlation between air-tightness of building envelope and building load was analyzed for a super tall building.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제51권1호
• /
• pp.22-30
• /
• 2002

ln this paper, it was reported the developed results of the monitoring unit for 72.5kY GIS which it is one part of the monitoring system for the substation that Korea Railway Company is promoting. In order to monitor the operational status of GIS, four parameters were chosen: the number of times of the circuit breaker switching, tightness of the gas-sealed units (circuit breaker / disconnecting switch / earthing switch), the number of times of the lightning arrestor operating and the leakage current of the lighting arrester. We constructed the monitoring system that can be judged the operating condition of the GIS from the signal of the suitable sensor for the purpose. Therefore, it is possible to on line monitoring for the condition of the GlS without efforts of the Periodic inspection.

• Communications for Statistical Applications and Methods
• /
• 제16권3호
• /
• pp.529-540
• /
• 2009

In this paper, we present some results on weak laws of large numbers for weighted sums of fuzzy random variables taking values in the space of fuzzy numbers of the real line R. We first give improvements of WLLN for weighted sums of convex-compactly uniformly integrable fuzzy random variables obtained by Joo and Hyun (2005). And then, we consider the case that the averages of expectations of fuzzy random variables converges. As results, WLLN for weighted sums of convexly tight or identically distributed case is obtained.

• 설비공학논문집
• /
• 제22권6호
• /
• pp.361-368
• /
• 2010

Due to the insulation and the air-tightness requirement in modern buildings have resulted NBS(New Building Syndrome) and SBS(Sick Building Syndrome) of IAQ problems. Therefore, energy efficient way of solving such IAQ issues are of major concern in these days and building industries. This paper introduces a method to improve thermal performance with a DI(Dynamic Insulation) concept. The characteristic of the dynamic insulation is that the lower U-value as the higher air velocity through the DI in a micro level. A thermal performance monitoring study has been conducted to show the energy impact of porous DI over the static insulation material. The results show that up to 45% could be improved in the case with DI compared to the conventional insulation.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
• /
• pp.129-134
• /
• 2008

Generally the window of the building is an objective of mining and having a distant view and also for a circulation it will can open and shut because becomes the structure insulation, the meat detailed drawing it does a very difficult portion, it is. And, recently the use of heat recovery ventilator has increased rapidly for improvement of air Quality and energy saving in building. But, the high efficient heat exchange will be more increasable than water vapors which were only occurred residential active. Purpose of this study is measurement of thermal performance about heat-recovery system integrated window. The result of the window thermal resistance is 1.80 $W/m^2K$ by KS F 2278. Air tightness is 5.96 m3/m2h at 4 Pa by KS F 2292.

• Journal of Welding and Joining
• /
• 제33권6호
• /
• pp.42-48
• /
• 2015

Reduced activation ferritic/martensitic steels are recognized as the primary candidate structural materials for fusion blanket systems. Welding is an inevitable for breeding blanket for pressure tightness and radioisotope confinement. Especially, TIG welding was chosen for sealing because it has the largest gap allowance compared to the other welding methods, and its properties are controllable by feed wire and welding conditions. In this study, the low cycle fatigue test using two-type gage such as extensometer and strain gage was applied to the TIG welded joint of F82H steel, for evaluating fatigue damage accumulation behavior of the HAZs. As the result, the over-tempered HAZ have shown a higher fatigue damage accumulation compared with other materials at all the testing conditions.

• 상하수도학회지
• /
• 제26권3호
• /
• pp.343-354
• /
• 2012

A electro-foaming fusion wrap fitting for polyethylene sewer pipe was built and foaming mechanism has been studied. A foaming sheet, supporting sheet and clamping band is assembled into a all-in-one structured electro-foaming fusion wrap fitting. To specify foaming and fusion of electro-foaming fusion wrap for PE sewer pipe, series of fusion tests were performed in various conditions. A parallel plate compression test up to 50 % of inner diameter deflection has been performed to check integrity of fusion quality and it was found that there were no visible signs of crack in wrapped area of fitting. Also air tightness test based on KS M 3511-2 has been performed to evaluate perfectness of wrap fusion quality and we found there were no pressure drop up to 10 times higher value than KS standard regulation.

• Journal of Chest Surgery
• /
• 제11권1호
• /
• pp.26-34
• /
• 1978

We observed 82 cases of primary lung cancer clinically and statistically, which had been experienced at the dept. of thoracic surgery, Chonnam University Hospital, during the period of 13 years from 1964 to 1967. The results obtained were as follows: Peak incidence of age was from 5th decade to 6th decade, and the ratio of male to female was 3: 1. The frequency of lung cancer was higher in the heavy smoker than in the lighter smoker, and undifferentiated carcinoma showed low resectability in spite of the shorter clinical duration. Major symptoms were coughing and chest tightness & pain, especially coughing was initial symptom in the majority of patients. Of the 82 cases, operation was performed in the 32 cases [39%], but resection was possible in the 22 cases [27%]. The delaying factors led patients to an inoperable stage were physician’s misdiagnosis of bronchogenic carcinoma due to non-specific symptoms and signs of the patients, old age patients were dependence on herb medicine, and poor economical condition of the patients in our region especially. Basic conditions of treatment in lung cancer were early detection & early surgery, so, chest P-A would be checked per 3 to 6 months interval associated with sputum cytology in the smoker over 45 age routinely.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2002년도 춘계 총회 및 학술발표회
• /
• pp.35-41
• /
• 2002

Dense oxygen ionic conducting materials can be used for oxygen separation membranes at high temperatures. However, they show relatively low permeation flux because of their large resistances. To reduce resistances and improve the oxygen permeation flux, thin dense yttria-stabilized-zirconia (YSZ)/Pd composite dual-phase membranes were fabricated by a new approach that combines the reservoir method and chemical vapor deposition (CVD). A thin porous YSZ layer was coated on a porous alumina support by dip-coating the YSZ suspension. A continuous Pd phase was formed inside pores of the YSZ layer by the reservoir method. The residual pores of the YSZ/Pd layer were plugged with yttria/zirconia by CVD to ensure the gas tightness of the membranes. The oxygen permeation fluxes through these composite membrane were 2.0$\times$10$^{-8}$ mol/cm$^2$.s and 4.8$\times$10$^{-8}$ mol/cm$^2$.s at 105$0^{\circ}C$ when air and oxygen were used as the permeate gases, respectively. These oxygen permeation values are about 1 order of magnitude higher than those of pure YSZ membranes prepared under similar conditions.