• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.5
• /
• pp.97-102
• /
• 2018

Combat vehicles require high levels of maneuverability, firepower, armor, and operability. A high-performance power system is required for optimal maneuverability. The fuel pump which supplies fuel stably is very important to achieve this. The fuel pump consists of a pump part, a motor part, and a control part. It is equipped with a BLDC motor. Numerous failures of the fuel pump occurred during vehicle operation when exposed to vibration, shock, and high temperature. The cause of failure was confirmed to be stator slip of the BLDC motor. Stator slip is a consequence of the interference loss between the stator and the housing of the motor part in an high temperature environment. The failure of the fuel pump was solved through size control of the motor housing and the stator. We performed vibration testing at high temperature for verification. This study contributes to improving the reliability of combat vehicles.

• Journal of Environmental Science International
• /
• v.30 no.3
• /
• pp.289-293
• /
• 2021

This study was conducted to investigate the distribution of duck production in duck housing as a function of the breeding period. The items in duck production distribution included body weight, feed intake, feed conversion ratio, and average duck production. All data were based on eight cycles (June and December, 2017; February, June, August, September, and November, 2018; February, 2019) at Farm Site 1 through 7. The most optimal results in the duck production distribution were observed at Site 1 for weight gain, feed intake, and feed efficiency. This could be explained by the fact that Site 1 was well managed in environmental improvement and sustainability. Based on these data, selective alternatives to improve duck production in duck farms are recommended as follows: first, proper management and recording of litter used as a flooring material are required, and second, continuous management such as temperature, relative humidity and ventilation is needed. Lastly, it is necessary to change duck facilities by introducing environmental management techniques. Furthermore, efforts to improve the overall facilities and management of duck breeding farms through additional field studies are needed in the future.

• Design & Manufacturing
• /
• v.15 no.4
• /
• pp.32-36
• /
• 2021

In this study, the cause of the decrease in transmittance of the outer lens among the causes of the decrease in the amount of light in the automobile headlamp was identified, and the improvement method was selected to determine the effect. The causes of defects that lower the transmittance of the outer lens are divided into a moisture problem and a haze problem. The moisture problem is caused by the temperature difference between the inside and the outside of the head lamp, and the haze problem occurs when the heat inside the head lamp evaporates the haze component contained in the plastic material and attaches it to the outer lens. In order to improve the haze problem that occurs in plastic raw materials, the structures of the bulb light source type headlamp and the LED chip light source type headlamp were analyzed. Among them, the housing material of the LED chip light source type headlamp, which is structurally prone to haze gas, was selected as the test target. In the mass-production injection process of the housing, the drying process was selected as a method to minimize haze gas without adding a separate production process. After extracting a sample every drying time at a constant drying temperature, the sample was put into a haze tester and the residual amount of haze gas was measured. As a result, it was confirmed that the residual amount of Haze gas in the material decreased as the drying time increased.

• International conference on construction engineering and project management
• /
• 2007.03a
• /
• pp.711-720
• /
• 2007

Apartment housing in the Korean domestic construction industry has had various and high-quality finishing work since the enforcement of price deregulation in 1998. Before the enforcement of price deregulation, feasibility studies of housing projects have not had particular difficulties as uniform description of finishing work items were reflected and finishing work cost also was equalized. However, the recent distinction of finishing work based on the same floor plan brings about project cost variation, along with many effects on construction management due to project cost increment. Accordingly, this paper suggests the improved plan of cost management to control the feasibility study result consistently during the life cycle of a project through an analysis based on cost management phase due to cost blackout, appearing at the commencement of a project, cost gradation caused by high-quality finishing work item, and cost reduction due to the degradation of finishing work after analysis of current apartment construction process focused on finishing work using the IDEF process analysis technique.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.5
• /
• pp.748-754
• /
• 2018

Objective: The preference evaluation of cattle is an important factor for estimation and improvement of the grazing amounts of newly introduced or bred grasses or cultivars in barn. This study was performed to assess the grazing behavior (the amount of grazing and/or the grazing speed) of cattle as indirect method using newly bred Brachiaria ruziziensis tetraploid strain 'OKI-1'(BR) hay as treatment group and Cloris gayana 'Callide' (CG) hay as control group. It also compared the feasibility of using behavioral differences between two groups as one criteria for evaluating preference by Japanese black cattle in barn. Methods: Three experiments were carried out using 12 growing Japanese Black cattle including 6 males and 6 females. In each experiment, the four Japanese Black cattle (2 males and 2 females) were placed in separated stall and allowed to graze BR and CG in manger that was separated into two portions for about 30 min. The position and behavior of the cattle were recorded, and weighed the residual of each gay at 15 and 30 minutes after experiment start. Results: The BR was superior to CG in chemical composition such as protein, fibers and non-fibrous carbohydrate. The cattle, over all, tended to prefer BR over CG in the first half 15 minutes in terms of the time spent and amount of grazing. Additionally, growing cattle exhibited neophilia for BR bred newly. Conclusion: These findings indicated the current approach could be applied for one of criteria to evaluate the preference of hay by Japanese black cattle under indoor housing environment.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2009.11a
• /
• pp.104-108
• /
• 2009

Rapid urbanization resulted in expansion of urban area and increase of population bringing deepened housing shortage. Supply-oriented housing policy made apartment a representative residential space in Korea in spite of the short history of apartment. This study analyzed the shape and arrangement of main building by year and the microclimate in the complex depending on the number of floors. The purpose of this study was to present the basic data in developing apartment complex to solve problems like the stagnation of pollution source and the rise of temperature due to the declined ventilation in apartment complex, and the worsened urban heat island phenomenon due to the impeded flow of wind. This study rearranged the shape and arrangement of main building by year and the tendency of the number of floors by year in the process of change, by generalizing the process of change of apartment complex, a representative modern residential space through preliminary research. Based on it, 8 object lot by age was selected and simulated by using Envi-met. Simulation identified that the change of apartment complex takes place having a positive effect on microclimate in the apartment complex and the microclimate in the apartment complex is influenced a lot by the shape of complex. If in future apartment complex plan, a systematic legal criteria of design is made about the shape and arrangement of main building, it might have a positive effect on the improvement of microclimate in the apartment complex, a representative residential space in Korea.

• Korean Journal of Construction Engineering and Management
• /
• v.7 no.3 s.31
• /
• pp.149-158
• /
• 2006

For construction projects, it is required to estimate the Environmental Management Cost(EMC) for pollution prevention, using the calculation standards prescribed in the Construction Technology Management Law(CTML). However, the EMC standards are difficult to utilize without definite site information. Therefore, it is needed a new calculation method reflecting project site information. According to the definition of EMC in the CTML, this study identifies the EMC items and classifies them into the pollution types such as air, water, noise, waste and others. With this EMC classification, the stud:』 analyzes using the SPSS the EMC for the 78 new multi-housing projects, which were executed during the past three years, 2000-2002. And then an EMC estimating matrix is developed with simple information such as site location and size of area from historical data. The proposed matrix can be effectively used to check and control budgeting and estimating the EMC of the multi-housing projects. In addition, the proposed EMC matrix are validated through a case study.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.20 no.6
• /
• pp.67-77
• /
• 2017

Demands for housing has diversified recently due to low birth rate and the growth of aging population. Also, a share of idle houses and obsolete houses over 20 years old is gradually rising. Therefore, there is a need for a sustainable, environment-friendly improvement policy that is in line with a new housing paradigm and avoids full-scale new construction, such as a customized housing renovation plan considering local economic circumstances. Therefore, afforestation system applicable to buildings are assessed positively, but lack objective performance evaluation. Through one-year, long-term monitoring of replicated obsolete buildings that have poor insulation performance, this study calculated monthly average power consumption and analyzed power charges by applying pricing plans before and after the revision of progressive tax in order to examine economic effects expected by applying the afforestation system. In the obsolete buildings, the study showed that monthly average power consumption was reduced by 16.6kWh with 5.2% average reduction rate. Highest reduction was made in July at 11.3%. Aggregate monthly power consumption charges were relatively high in winter before and after the revision of progressive tax. Power charges reduction effect was highest in March when monthly power consumption was reduced to 300kWh level by applying the afforestation system.

• Journal of the Korean Institute of Rural Architecture
• /
• v.20 no.2
• /
• pp.37-48
• /
• 2018

As part of the housing policy on the concentration of large cities due to economic growth, large-scale construction was carried out for many years, but the focus of the quality improvement was largely on the quality supply. With criticism that such large-scale housing construction is distorting urban and rural landscape, it was forced from 2000 to apply the district unit plan to the development of housing sites with a certain scale and the district unit plan. In addition, it evaluated how the rural and urban landscape would look during the planning of the District Unit Plan, and how the resulting space would have an objective effect on urban and rural areas and how it would be evaluated for harmony. Therefore, this study applies and evaluates the weighted value of each inspection point selected by Lee lim jung (2016) to compare and analyze the actual application of the inspection point and the review report. As a result, it was assessed that no rational landscape planning was established because many simulation presentations were made at the lower priority point, and little was presented at the higher priority. The view point weights were distributed in the Landscape Review of the District Unit Plan with a score of up to 36 points from the lowest of 6 points, which resulted in the view simulation being reviewed in terms of various aspects.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2008.11a
• /
• pp.140-143
• /
• 2008

As the number of family living alone is expected to soar due to a change in socio-demographics like divorce, more middle-aged women returning to work, homes become smaller and so on. In addition to in 2020 these people will be increase so that 85 percent of the Koreans compose elderly living alone who is over 65. This study aims at developing a sharing-typed elderly people-centered rental model which is accessible in the community integration dimension as an alternative and finding out theirconscious, their need about residence. and we need to check about their major requirements on improvement step by step. so that we suggest the desirable way on the existing multi house. The model provides benefits in the social, economical and pragmatic dimensions as the families living alone get together and living with others, Particularly, as a residence model which reduces a psychological loneliness and at the same time enables the elderly to continue to live a life in the community while they live together with other people, this model could be a strategy which supports the "Aging in Place." This study is in progress via small group workshop which debate gradually about special subject with similar group member. So we can find the residence's preference on living environment in various condition and the member can imagine freely on their future living arrangement by giving the various informations which can be proceed in future. The workshop proceed three times. at the first workshop, we're check their living environment and satisfaction level. and second time we give the knowledge about shared-type rental house then discuss about the model. and last time we're listen to the residence's opinion.