• Geomechanics and Engineering
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• 제18권5호
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• pp.545-554
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• 2019

The customary approach used in the blast vibration analysis is to derive empirical relations between the peak particle velocities of blast-induced waves and the scaled distance, and to develop patterns limiting the amounts of explosives. During the periods when excavations involving blasting were performed at sites far from residential areas and infrastructure works, this method based on empirical correlations could be effective in reducing vibrations. However, blasting procedures applied by the fast-moving mining and construction industries today can be very close to, in particular cities, residential areas, pipelines, geothermal sites, etc., and this reveals the need to minimize blast vibrations not only by limiting the use of explosives, but also employing new scientific and technological methods. The conventional methodology in minimizing blast vibrations involves the steps of i) measuring by seismograph peak particle velocity induced by blasting, ii) defining ground transmission constants between the blasting area and the target station, iii) finding out the empirical relation involving the propagation of seismic waves, and iv) employing this relation to identify highest amount of explosive that may safely be fired at a time for blasting. This paper addresses practical difficulties during the implementation of this conventional method, particularly the defects and errors in data evaluation and analysis; illustrates the disadvantages of the method; emphasizes essential considerations in case the method is implemented; and finally discusses methods that would fit better to the conditions and demands of the present time compared to the conventional method that intrinsically hosts the abovementioned disadvantages.

• 한국대기환경학회지
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• 제28권5호
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• pp.495-505
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• 2012

Modeling the effects of high-rise buildings on thermo-dynamic conditions and meteorological fields over a coastal urban area was conducted using the modified meso-urban meteorological model (Urbanized MM5; uMM5) with the urban canopy parameterization (UCP) and the high-resolution inputs (urban morphology, land-use/land-cover sub-grid distribution, and high-quality digital elevation model data sets). Sensitivity simulations was performed during a typical sea-breeze episode (4~8 August 2006). Comparison between simulations with real urban morphology and changed urban morphology (i.e. high-rise buildings to low residential houses) showed that high-rise buildings could play an important role in urban heat island and land-sea breeze circulation. The major changes in urban meteorologic conditions are followings: significant increase in daytime temperature nearly by $1.0^{\circ}C$ due to sensible heat flux emitted from high density residential houses, decrease in nighttime temperature nearly by $1.0^{\circ}C$ because of the reduction in the storage heat flux emitted from high-rise buildings, and large increase in wind speed (maximum 2 m $s^{-1}$) during the daytime due to lessen drag-force or increased gradient temperature over coastal area.

• 한국응급구조학회지
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• 제10권1호
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• pp.13-21
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• 2006

Purpose: This study aims to examine characteristics and actual conditions of patients using emergency room at farming and fishing villages, solve overcrowding of emergency room at the tertiary hospital and activate local emergency clinics. Methods: It examines department of diagnosis and treatment, vehicles used, sex, age, residential area, visit hour, length of stay, presence or absence of trauma, measures after first aid and degree of severity based on medical records of 6,740 patients using emergency room at farming and fishing villages from Jan. 1 to Dec. 31, 2005. Conclusion : 1. Sex distribution of patients of emergency room was male 54.9% and female 45.1% and age distribution between over 40 and below 50 was most as 15.9%. 2. Transport means to emergency room were 91.4 of private car and others (public transport and going on foot), 7.5 of 119, 129 and police car and 1.0% of ambulance. 3. According to distribution of residential areas of emergency patients, 38.9% were Eup area, 42.1% Myeon area, 11.4% distant area and 7.5% adjacent area. 4. According to distribution of emergency patients by department of diagnosis and treatment, internal medicine was most as 35.8% and 55% of patients visited emergency room from 3:31 p.m. to 11:30 p.m.. 5. According to total hours of diagnosis and treatment of subjects, 51.2% were within 30min. and cases of non-trauma disease were 68.2%. 6. According to degree of emergency of emergency patients, non-emergency cases were 65.3%, urgent cases 27.7% and emergency cases 7.0% and 74.2% of patients returned home after first aid and 20.6% of them hospitalized. In conclusion, characteristics and diversification of patients should be examined and efforts by government and local medical institutions which must organize emergency system and facility and personnel levels suitable to regional conditions are needed in order to prevent overcrowding of emergency center of the tertiary hospital and activate local emergency center.

• 한국콘텐츠학회논문지
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• 제13권10호
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• pp.556-564
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• 2013

본 연구는 미분양 아파트 수요자를 대상으로 선호요인을 분석하고 향후 민간측면에서 미분양 아파트 해소를 위한 마케팅 전략에 대해 연구하고자 한다. 연구방법은 미분양 아파트 수요자 선호요인을 도출한 뒤 컨조인트 분석을 통해 가장 중요하게 판단하는 요인과 상대적으로 포기할 수 있는 요인을 도출하였다. 분석결과, 첫째, 미분양 아파트 수요자들은 주택 구매 선택에 있어 미분양에 따른 혜택(분양가 인하 및 보장제)을 입지환경 및 거주환경 보다 우선적으로 고려하는 것으로 나타났다. 둘째, 미분양 아파트 수요자들은 입지환경과 관련해 대중교통 이용이 양호한 환경을 가장 중요하게 고려하며, 거주환경과 관련해서는 단지 내 친환경 수준을 중요하게 고려하는 것으로 나타났다. 셋째, 미분양 아파트인 만큼 가격전략에서는 납부조건 완화보다는 분양가 인하를 선호하는 것으로 나타났다. 마지막으로 홍보전략은 주택전시관이나 설명회를 통해 홍보하는 것이 가장 효과적인 것으로 분석되었다.

• 한국환경보건학회지
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• 제32권4호
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• pp.324-335
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• 2006

Five sampling sites were selected to investigate the distribution characteristics of air pollutants with pollution sources and weather conditions in Ulsan. $SO_2,\;NO_2,\;O_3,\;CO,\;PM_{10}$ concentrations and weather conditions with time were analyzed by using several statistical methods. Also, the distribution characteristics of ambient air quality were estimated by pollution-rose and multi-regression analysis. As a result of the analysis, $NO_2,\;CO\;and\;PM_{10}$ concentrations were high in winter season, whereas $SO_2\;and\;O_3$ concentrations were high in summer season. This concentration distribution was caused by the unfavorable geographical location, which the residential area was located at the downwind direction to industrial area. From the pollution-rose, we confirmed that each pollutant influenced the downwind residential areas because of seasonal wind direction. $SO_2$ concentration has shown positive correlation of $0.2{\simm}0.3$ for $NO_2,\;PM_{10}$ and temperature, while $O_3$ concentration has shown negative correlation. Also, $NO_2$ and CO concentrations, pollutants generated by combustion, have shown positive correlation, while $O_3$ concentration and temperature have shown negative correlation. Therefore, it could be suggested that a seasonal air quality policy and a new guideline of air quality was necessary in each season with wind directions to reduce the air pollution level in Ulsan.

• KIEAE Journal
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• 제15권4호
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• pp.91-104
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• 2015

Recently, various researches for the improvement of Han-ok performance carried out. But, most of them are tend to come from the viewpoint of suppliers rather than that of Han-ok habitants. It means that environmental elements which real habitants feel are not reflected in the design of initial Han-ok design. Therefore, it is necessary that many researchers should analyze the degree of dwelling satisfaction derived from real life. Purpose: The purpose of this study is to find the avaliable factors that need to be considered in the process of initial Han-ok design and construction through the analysis on the living performance satisfaction ratio of modern New Han-ok's habitants. Method: To achieve this goal, surveys were carried out in 83 Han-oks which actual habitants were living, located in 14 happy villages Jeonnam province. Following are survey items about residential environmental conditions; kinds of wall material, gap(connection joint between wall and wood columns) reinforcement or not, kinds of window, kinds of facilities around windows, kinds of heating source, heating types(single, multiple), financial burdens, selective heating or not and so on. Result: The results of this study may be used to improve the living performance satisfaction ratio of new Han-ok habitants and as a basis for the specifying the desired thermal comfort environment of dwelling.

• 한국농촌건축학회논문집
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• 제16권4호
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• pp.91-98
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• 2014

In this study, the current conditions of the farming and fishing village housing improvement projects that were promoted for the last five years were examined, the results of the survey conducted among the promoters of the farming and fishing village housing improvement projects with regard to their level of satisfaction were analyzed, and the outcomes of the housing improvement projects and the improvement needs were derived for utilization as basic data for preparing an improvement plan for "the farming and fishing village housing improvement projects". Below are the results of this study and the proposals based on such. In view of the reality that the recipients of the farming and fishing village housing improvement projects are limited to the rural residents who are able to repay their loans, ways of actualizing the current loan limit of 60 million won should be prepared, taking into account the actual construction cost. Moreover, as the rural residents do not live on monthly salaries, the repayment periods of their loans should be adjusted to make them payable on a quarterly or a semi-annual basis, reflecting the reality of the farming villages, where loan repayment is based on the residents' yearly income. Further, policies guaranteeing the residential rights of those belonging to the low-income bracket who are unable to repay their loans must be established at the soonest possible time. In view of the realities in the farming villages, where there are 640,000 houses that are over 31 years old, the supply of 10,000 houses as part of the housing improvement projects is grossly inadequate. Of course, it cannot be said that all the residents who are living in worn-out houses have the necessary conditions for receiving support from the housing improvement fund. Therefore, policies supporting the speedy improvement of worn-out houses and guaranteeing the residential rights of those belonging to the low-income bracket are urgently needed.

• 한국실내디자인학회논문집
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• 제28호
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• pp.92-99
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• 2001

During last 4 decades of industrial development, apartment has been rapidly disseminated throughout the nation. Its main progress, however, only appeared in quantity, not in quality. To promote housing industry in more way and to enhance peoples' life quality through the better housing environment, housing plan should be based on living items including furniture, appliances and etc. Not enough research has been done to find out living items for better house plan development and furniture design. Among living items, furniture reflects both directly and indirectly people's lifestyle and way of living. This study attempted to find out the pattern of furniture possession which people own in their bedrooms. An in depth questionnaire survey of 600 households was carried during the year 2000. A variety of patterns were found which indicated diverse living conditions within a very similar uniform multifamily apartment complex. The result of this study will be helpful to understand the living conditions in a more systematic way and to generate new concept for both residential unit plan and furniture design.

• 산업기술연구
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• 제17권
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• pp.5-10
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• 1997

Fatigue tests were performed to investigate how much vary the fatigue limit under the different surface conditions on Carbon Steel(SM55C). Four types of specimen which have different surface roughness each other, Series A by turning, Series B by grinding, Series C by polishing and Series D by roller finishing showed the fatigue limit of 265, 320, 335 and 365MPa, respectively. Series D show 36% higher than Series A, which is caused by compressive residential stress on the surface. Therefore, roller finishing machining is helpful not only increase the fatigue limit but also improve the surface roughness. Moreover, to predict the fatigue limit under the conditions of knowing surface roughness and hardness of specimen, ${\sqrt{area}}$ area parameter method is very useful.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.822-828
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• 2001

Three-phase four-wire electrical distribution systems are widely employed in manufacturing plants, commercial and residential buildings. Due to the nonlinear loads connected to the distribution system, the neutral conductor carries excessive harmonic currents even under balanced loading since the triplen harmonics in phase currents do not cancel each other. This may result in wiring failure of the neutral conductor and overloading of the distribution transformer. In response to these concerns, a cost-effective neutral current harmonic suppressor system has been proposed [6]. This paper proposes an improved control method for the harmonic suppressor system under unbalanced load conditions. The proposed control method compensates for only the harmonic components in the neutral conductor, and the zero-sequence fundamental component due to unbalanced loading is prevented from flowing through the harmonic suppressor system. This remedies overloading and power loss of the system. The experimental results on a prototype validate the proposed control approach.