• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.668-672
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• 2001

The utility interactive sinewave modulated inverter for the solar photovoltaic (PV) power conversion and conditioning with a new high frequency pulse modulated link is presented for domestic residential applications. As compared with the conventional full-bridge hard switching PWM inverter with a high frequency AC link, the simplest single-ended quasi-resonant soft switching sinewave modulated inverter with a duty cycle pulse control is implemented, resulting in size and weight reduction and low-cost. This paper presents a prototype circuit of the single-ended zero voltage soft switching sinewave inverter for solar power conditioner and its operating principle. In addition, this paper proposes a control system to deliver high quality output current. Major design of each component and the power loss analysis under actual power processing is also discussed from an experimental point of view. A newly developed interactive sinewave power processor which has $92.5\%$ efficiencty at 4kW output is demonstrated. It is designed 540mm-300mm-125mm in size, and 20kg in weight.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.2
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• pp.9-17
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• 2020

The ratio of the deterioration housing in rural area was 29.6%, but it was 18.3% in urban area based on a 2018 survey. In consideration of the point, this study aims to analyze the actual condition of indoor air quality in rural houses to provide basic data for improving the indoor air environment. It was investigated 15housings of Hongseong-gun, Chungchengnam-do. To investigate the correlation between indoor air quality and housing type, both the field survey of housing type and precision diagnosis of concentration of indoor air pollutants such as HCHO, TVOC, Fine dust(PM-10, PM-2.5), CO₂, Radon. The results of this study are as follows. First, according to the average value of each element of rural old housing, the construction year was distributed in 1939~2004, and 12households(80%) living in houses older than 30years have passed for about 46years. As for the housing area, more than 12houses(80%) of 60㎡ or more and 3 houses (20%) of less than 60㎡ were often living in relatively small-scale housing. Second, as a result of measuring indoor air pollutants in rural houses, substances exceeding the standard values were found in HCHO, TVOC, CO₂. Third, in the case of Fine dust and Radon, none of such factors were exceeded the standard. Fourth, there was no significant difference in indoor air quality depending on housing type in rural houses. This paper is expected to contribute to the regional development projects and effective implementation of rural policies.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.328-333
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• 2006

A few methodologies have been recently developed to estimate the environmental affect when various materials and components are used in building life cycle. The direct survey method has limitations to analyze the environmental problems because of the limit of survey scope and cost. Therefore, another indirect method has been developed as alternatives. The indirect method is represented as input-output analysis. This paper aimed at analyzing the estimation the environmental affect of building materials and works at building construction, utilizing the input-output analysis as a indirect estimation method. The results suggested that the building works is overally responsible for the energy consumption and $CO_2$ emission. In other words, Over the 80% of the total consumption and $CO_2$ emission are resulted at the building work.

• Journal of the Korean housing association
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• v.14 no.5
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• pp.65-74
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• 2003

Recently, the environmental conservation has been emphasized over the world. Building industry should carefully reflected the development focused on the economic aspect as well as the environmental considerations. Therefore, it requires the technology development to mitigate the environmental pollution through the reducement of the energy and resources usage amount over the building life cycle. For these, it should be required to set up the analysis methodology to grasp the amount of the environmental pollution and energy and resources in each step of building life cycle. In this paper, it aimed at preparing the analysis process and analyzing the embodied energy and $CO_2$ and $SO_x$ emission according to the building work, field work, mechanical and electrical work on the new building and remodelling, utilizing the inventory analysis which is one of the LCA process.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.17-28
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• 2009

PEB system is more economical when compared with structures commonly used Hot rolled and welded light H-beam was introduced in the Standard Livestock Housing. This study suggested more economical technology for structural design by the reduction of live load, relief of deflection limit and reduction of importance factor. And, when applying wind Load as a result of examination with Low Rise Building Systems Manual considering open model, we can know that when the wind load is big, enclosed model is more stable than open model. In short, Suggesting more economical model and providing the method to reduce natural disaster, by the application of PEB system and the development of technology for structural design, are considered to strengthen the competitive power of farmhouse.

• Journal of Korea Foundry Society
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• v.24 no.6
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• pp.347-355
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• 2004

In the die casting process, the flow of liquid metal has significant influence on the quality of casting products and die life. For the optimal process design of automobile gear housing, various analyses were performed in this study by using computer simulation code, MAGMAsoft. The simulation has been focused on the molten metal behaviors during the mold filling and solidification stages for the sound casting products. Also the internal defects were predicted by application of air pressure and feeding criteria.

• Journal of Sensor Science and Technology
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• v.11 no.3
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• pp.138-144
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• 2002

The silicon piezoresistive pressure sensor is made by semiconductor process to obtain stainless steel isolated type pressure sensor. The sensor is loaded on a stainless steel housing with glass molding, $50\;{\mu}m$ stainless steel thin film is welded, and the stainless steel housing encapsulated by silicone oil. The performance of fabricated the pressure sensor has 10 bar pressure range. The XTR105 of exclusive transmitter chip is used the pressure transmitter that output current is 4 - 20 mA. The accuracy is ${\pm}5%$ FS, however, the accuracy is ${\pm}1%$ FS when the sensor is compensated temperature.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.8-15
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• 2021

Cold forging is a method in which molding is performed at room temperature. It has a high material recovery rate and dimensional precision and produces excellent surface quality, and it is mainly used for the production of bolted or housing products. The lifespan of cold forging molds is generally determined by the wear of the mold, plastic deformation of the mold, and fatigue strength. Cold forging molds are frequently damaged due to fatigue destruction rather than wear and plastic deformation in a high-temperature environment as it is molded at room temperature without preheating the raw material and mold. Based on the results analyzed through FEM, an effective mold structure design method was proposed by analyzing the changes in tensile and compressive stresses on molds according to the number of molds and reinforcement rings and comparing the product geometry and mold stress using three existing mold models.

• Journal of Biosystems Engineering
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• v.24 no.5
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• pp.425-430
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• 1999

Complex environmental control systems were developed, which control properly the pig's environment in windowless pig-housing based on the thermoregulatory behaviors of pigs and concentrations of noxious gases (CO2 and NH3). The this study was conducted to assess the performance of complex environmental control systems by raising weaned piglets and growing pigs under different seasonal conditions. Average daily gain of pigs in the experimental pig-housing was slightly higher than that of pigs in the conventional pig-housing. Average daily gain was not significantly different in winter and spring(P＞0.05), but was significantly different in summer(P＜0.05). Feed conversion rate of pigs in the experimental pig-housing was smaller than that of pigs in the conventional pig-housing. Feed conversion rate was not significantly different in environment for weaned piglets and growing pigs resulted in the improved daily gain, feed conversion rate, and carcass quality of the finishing pigs. These results showed that the performance of the complex environmental control systems in windowless pig-housing was excellent for weaned piglets and growing pigs.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.209-222
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• 2020

The purpose of this paper is to predict the future changes of housing through the Delphi technique. The targets to predict were set by housing type, housing space, housing demand, and architectural technology. The results were as follows: ① The influences of social and value perspectives on the change of housing type, space, and demand would be high, on the other hands, the influence of political perspective would be low. ② In terms of housing type, the increase in demand for downsizing housing for high-rise buildings and the possibility of realizing remote medical support services and homecare using big data are highly predicted. That is, ③ it is anticipated that IoTs will have a significant influences on future housing changes, and ④ enactment of co-housing and related laws by the sharing economy, services for maintenance through the supply of high-rise and high-density homes, housing support for residents, and advanced lease markets by developed architectural technology are expected as anticipated forms of future housing.