• New & Renewable Energy
• /
• v.10 no.2
• /
• pp.40-47
• /
• 2014

This study is intended to analyze the appropriate scope for 9.9MW biomass cogeneration, feasibility and sensitivity according to changing market situation. In the study, the heat load is classified into three types to predict heat sales and find out the appropriate scope of thermal business that is operated in CHP 34.42 Gcal/h, PLBwg 70 Gcal/h of cogeneration. the feasibility is estimated based on internal rate of return (IRR) and net present value(NPV). the sensitivity is analyzed in terms of biomass fuel cost, unit price of heating cost, investment cost, SMP unit price and REC unit price.

• Journal of the Korean housing association
• /
• v.18 no.2
• /
• pp.129-136
• /
• 2007

This study, as a case study of four university dormitories in Gwangju, examined the situation of interior space and conducted a quantitative survey investigating importance about the interior space and assessment factors of residential environment on users. Then user satisfaction at the assessment factors of residential environment was analyzed to draw problems and explore improvement. The results showed the following problems that should be resolved: Bedrooms should increase the area of convex space; toilets and bathrooms should be changed into a cluster type at least in common use by floor; rest space should reinforce heating and cooling system; robby space should become mixed space for various user's behavior; private fitness rooms should be planned as group fitness space; private libraries should reinforce lighting facilities; and computer rooms should complement and improve HVAC.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.3
• /
• pp.473-479
• /
• 2015

Thermal relays are sometimes used instead of long time overcurrent relays for motor protection. But, it is difficult for any relay design engineer to adequately approximate motor heating curves which represent the average of a difficult-to-define thermal zone. Thermal relays frequently may not provide sufficient protection on heavy overloads. Digital multifunction relays are microprocessor-based devices. These relays offer highly reliable and advanced protection of motors. If a situation can be mathematically described, the microprocessor in a digital relay can be programmed to tackle that problem. Today's motor protection is accomplished with digital protective relays. Digital relays offer additional, highly important features to complement protection. The best way to prevent short in motor is to not overheat and degrade the insulation.

• Solar Energy
• /
• v.6 no.2
• /
• pp.33-42
• /
• 1986

The purpose of this paper is to research the performance of the energy in a case of the earth bermed House designed to be suitable for Korean situation in comparison with a conventional housing. The result of this study can be summerized as follows; 1) Heating energy of the earth bermed house is saved 40.1% than that of the conventional housing in Korea. 2) The time-lag of the earth bermed house is 57 minutes longer than that of a conventional housing on account of the thermal capacity, so the earth bermed house has much more satisfactory thermostatic mitigation effect rather than the conventional housing.

• Journal of the Korean housing association
• /
• v.12 no.3
• /
• pp.75-83
• /
• 2001

The deteriorted high-rise apartments make a social problem in now days. As a result, and new alternative plan for deteriorted high-rise apartments such as the remodeling concept must be considered. This study aims to develop the remodeling items which is the guide lines when remodeling of the apartment will be conducted. Thorough the case studies of maintenance and repair status of the deteriorted apartments in seoul, reasonable guidelines for selection of remodeling items were developed. Physical maintenance items includes those that need major repair activity like wall painting, water proof roof, change/repairs/implement of heating system, boiler, city gas pipelines, cold and hot water pipes, elevators, cleaning of water tanks. The period of repair is shorter than the durable year of law or codes. As a result of the study, basic maintenance items and actual repair period were proposed. This result will be the basic guidelines for remodeling items.

• Journal of the Semiconductor & Display Technology
• /
• v.23 no.1
• /
• pp.52-55
• /
• 2024

In this paper, a state change study was conducted through Frequency Domain Reflectometry (FDR) technology for the process chamber of plasma equipment for semiconductor manufacturing. In the experiment, by direct connecting the network analyzer to the RF matcher input of the 300 mm plasma enhanced chemical vapor deposition (PECVD) chamber, S11 was measured in a situation where plasma was not applied, and the frequency domain reacting to the chamber state change was searched. Response factors to changes in the status, such as temperature, spacing of the heating chuck, internal pressure difference, and process gas supply state were confirmed. Through this, the frequency domain in which a change in the reflection value was detected through repeated experiments. The reliability of the measured micro-displacement was verified through reproducibility experiments.

• Atmosphere
• /
• v.26 no.4
• /
• pp.577-598
• /
• 2016

Observational and numerical studies have been carried out to understand the cause and development processes of the heavy rainfall over the middle Korean Peninsula during 0300 LST-1500 LST 29 June 2011 (LST = UTC + 0900). The heavy rainfall event occurred as the synoptic-scale ridge extended from Western Pacific Subtropical High (WPSH) was maintained over East Asia. Observational analysis indicates that the heavy rainfall is mainly due to scattered convective systems, formed over the Yellow Sea, traveling northeastward across the middle peninsula without further organization into larger systems during 0300 LST-0800 LST, and mesoscale convective systems (MCSs) over the Yellow Sea, transformed into a squall line, traveling eastward during 0800 LST-1500 LST. Organization of convective systems into MCSs can be found over the area of mesoscale trough and convergence zone in the northern end of the low-level jet (LLJ) after 0600 LST. Both observational and numerical investigations indicate that a strong LLJ extended from the East China Sea to the Yellow Sea plays an essential role for the occurrence of heavy rainfall. The strong LLJ develops in between the WPSH and a pressure trough over eastern China. Numerical experiments indicate that the land-sea contrast of solar heating of surface and latent heating due to convective developments are the major factors for the development of the pressure trough in eastern China. Numerical study has also revealed that the mountainous terrain including the mountain complex in the northern Korean Peninsula contributes to the increase of rainfall amount in the middle part of the peninsula.

• Journal of Environmental Science International
• /
• v.27 no.9
• /
• pp.763-770
• /
• 2018

Bioremediation in situ is heavily dependent on the oxygenic environment which would privide the dwelling microorganism with sufficient oxygen. The situation could be easily resolved with supply of an Oxygen Releasing Compound (ORC). In this paper we prepared that sort of material out of oyster shell powder (mostly calcium carbonate) that prevails every shore areas of the country. We used two different oxidizing methods in the first step of the whole manufacturing process-conventional heating in a furnace and an ultrasound generator to obtain calcium oxide. Then that calcium oxide was further oxidized into calcium peroxide which may release oxygen under a moisturized condition. The oxygen releasing experiments were run to test the performance of our products, and to determine the gas kinetics during the experiments. Interestingly, calcium peroxide derived from ultrasound treatment was much more energy-effective as ORC than that from furnace heating although the heat derived process was better than that of ultrasound in terms of oxygen content and its releasing rate. We also found that most of the data collected from the gas releasing experiments fairly supported an ordinary $1^{st}$ order kinetics to oxygen concentration, which shaped a sharp discharge of oxygen at the very early moment of each test.

• Journal of the Korean Home Economics Association
• /
• v.41 no.7
• /
• pp.59-71
• /
• 2003

Koreans were started moving to Yunhaju in Russia for escaping from tyrannical rule and famine in 1860's in Korea. Social and political situation of Russia were made it very hard to get to know about Korean's life there so far. But it was known that Korean Diaspora has been kept traditional way of living in without contacts between Korea for 140 years. This study examined the dwellings of Korean Diaspora in Yunhaju through reviewing related documents and records firstly and had a time to visit places which Koreans lived since 1860's for example Posyet(equation omitted), Suifen(equation omitted), Ussuriisk(equation omitted), Vladivostok(equation omitted), Partizansk(equation omitted) and took interviews with Koreans who lived there pre 1930's. Results of research were as following : 1) A first place to settle down for Koreans in Yunhaju was Posye(equation omitted) and scattered as time goes by far away from there. 2) Koreans were helping each other for living and they had their own self managing organizations in village there. 3) The villages which was made in Yunhaju by Koreans in the beginning were similar to traditional ones in Korea. 4) It was verified that dwellings which was built by Koreans in Yunhaju were similar to ones in north area in Korea. At that time lots of Korean Diaspora came from north part and they kept their own traditional way of building houses there for a long time. 5) Korean Diaspora have been kept traditional heating system ‘Ondol’ in their various types of houses until now in Yunhaju. Moreover, it is known that Russians prefer to set ‘Ondol’ in their houses recently as a very special and expensive heating system. This study would be a very good opportunity to standing out Korean history of housing in Yunhaju as well as evaluating their identification as Koreans. For this, it is needed to take more deep research in specific areas which could see more various types of housing and could compare ones between two countries.

• Journal of Fisheries and Marine Sciences Education
• /
• v.16 no.2
• /
• pp.181-186
• /
• 2004

The current situation of heating and cooling system of the classrooms of our country is rather poor compared not only to those of the developed nation's classrooms but also in case of other buildings such as financial institutions, office compounds. In winter, especially students have been in hatred state with respect to their health due to the fact that the heater is operated by petroleum. Korea has been heavily dependent on foreign nations for the very fact of importing energy in the form of oil or natural gas. So it is important to conserve energy and the picture with respect to energy remains similar till today as it was in long past periods. The purpose of this study is to contribute actively in energy economy and facilitate towards a healthy school life of students and other institutions proving a system of extracting energy from river water and then converting it into heat which can stand as an effective alternate of expensive oil or gas. Installing oil-stove based heating system at classrooms of school could get considerable attentation in several respects. The proposed heat energy could be collected unlimitedly both in time and in amount. The stable and uninterrupted heat energy from river water, optimally utilizing the typical-regional and geographical characteristics has the potential to be long-lasting in duration, cheap in energy economy and beneficial to health as well.