• 한국구조물진단유지관리공학회 논문집
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• 제6권1호
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• pp.205-212
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• 2002

The deterioration rate of concrete structures in urban area is accelerated due to rapid urbanization and environmental pollution. Repair materials and methods newly introduced in Korea should be investigated whether they are appropriate for the urban environment in Korea. The creek concrete structures are exposed in severe environmental condition than others. Based on these background in mind, the study is focused on evaluation of performance on repair materials used to rehabilitate creek concrete structures. To evaluate the performance of repair materials, four kinds of repair materials were selected based on polymer emulsion. This experimental study was conducted on fundamental performance such as setting time, compressive strength, bending strength, bonding strength, thermal expansion coefficient, and durability performance such as chloride diffusion, carbonation, chemical attack, and steel corrosion rate. On the basis of this study, the optimal repair material which is proper to the environment condition can be selected and service life of creek concrete structures can be extended. As a result, the life cycle cost can be reduced and the waste of material resources will be cut down.

• 보건행정학회지
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• 제1권1호
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• pp.27-41
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• 1991

The purpose of this study is to estimate cesarean section rate in Korea and analyze characteristics of health care institution which affect regional variation in the rate. We have searched vaginal and cesarean section deliveries among Diagnosis Related Group dat based upon insurance claim bills which have been submitted to Korean Insurance Corporation for two years since March, 1985. The results are as follows: 1. Out of all delivery cases of 87,500, cesarean section rate was 16.3% (14,299 cases). 2. Cesarean section rate varied according to size and ownership of health care institutions. In above 6- bed sized hospitals, the rate was at about 20% higher than small sized institutions, but rather in hospitals that have more than 500 beds, it was somewhat low. Classified by the hospital ownership, the rate was low at 18.4% in hospitals of religious organization and highest at private or corporate hospitals. 3. This study shows large regional variation in cesarean section rate; there are two times differences between region with the highest and lowest rate. Strongly related factors in that variation was the ownership of health care institution and urbanization variables. Low level of cesarean section rate in a region is explained by high proportion of delivery cases at institutions of religious organization and at insitutions in county level site. This result shows that apart from medical conditions of patients, indications of cesarean section differs from health care providers, and especially ownership of institution strongly affect them. Cesarean section rate in Korea is supposed to be at high level and development of utilization review programs to keep appropriate cesarean section rate is needed.

• 상하수도학회지
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• 제19권5호
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• pp.647-654
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• 2005

Recently, the economic losses caused by inundation are increasing due to the urbanization and industrialization, i.e., intensive land utilization and concentration of population and properties. It is regarded that the role of the storm sewer systems in urban areas becomes more important as one of the effective countermeasures for reducing the inundation losses. In this study, the effects of rainfall design frequency enhancement on the construction cost of the storm sewer systems were analyzed by increasing the design frequency from the present design frequency of the sewer systems, which is 5~10 years, to 15 years, 20 years and 30 years. The change rate functions of the design discharge and construction cost based on the various design frequencies were derived by regression analysis. According to the analysis, change the rate of design discharge at 15, 20, 30 years rainfall design frequencies were increased by 10%, 17.1%, and 27.2%, respectively, when compared to that at 10 year frequency. Furthermore, it was found that by increasing the design frequency from 10 years to 15 years, 20 years and 30 years, the construction costs were increased by 5.0%, 8.0% and 12.4%, respectively. Finally, their reliabilities need to be tested by applying the rate functions to the real storm sewer districts.

• 한국물환경학회지
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• 제33권5호
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• pp.563-571
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• 2017

Because of the rapid progress of urbanization in recent decades, the proportion of impervious areas in cities has increased. As a result, hydrological properties of urban streams have changed and non-point pollution sources have increased, that have had considerable influence on human life and ecosystems. To manage these situations, application of non-point pollution reduction facilities and LID facilities are expanding recently. In this study, it is investigated if rainfall interception rate used in design of non-point pollution reduction facilities can be applied to design of LID facilities. For this purpose, EPA SWMM is constructed for part of Noksan National Industrial Complex area wherein long-term observed storm water data can be obtained and storm water interception rates for various design capacities of a bio-retention LID facility reservoirs are estimated. While sensitivity of storm water interception rate according to design specifications of bio-retention facility is not large, sensitivity of storm water interception rate according to regional rainfall characteristics is relatively large. As a result of comparing present rainfall interception rate estimation method with the one proposed in this study, the present method is highly likely to overestimate performance of the bio-retention facility. Finally, a new storm water interception rate formula for bio-retention LID facility is proposed.

• 한국해양학회지:바다
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• 제10권4호
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• pp.196-203
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• 2005

부산항의 와편모조류 시스트를 연구하기 위하여 2003년에 11개 정점에서 표층 퇴적물을, 1개 정점에서 수직 퇴적물을 채집하였다. 표층 퇴적물에서 동정된 와편모조류 시스트는 총 12속 22종으로 $210\~869\;cysts/g$의 농도로 분포하고 있었다. 외항의 정점보다 내항의 정점에서 타가영양종의 비율이 높게 나타났는데, 이는 인근 하천으로부터 항내로 유입되는 오염물질과 방파제 건설로 인한 해수 교환율 저하로 외항보다는 내항의 수질이 악화되어 있는 상태를 반영한다. 수직 퇴적물의 퇴적속도는 2.0 mm/yr로 대략 지난 260년간을 나타내고 있었다. 와편모조류 시스트는 9속 18종으로 $79\~446\;cysts/g$의 농도 범위를 보이고 있었다. 수직 퇴적물 시료에서 $14\~15cm$($1928\~1933$년)층을 기준으로 하부보다 상부에서 시스트 농도가 낮고 타가영양종의 비율이 증가하였는데 이는 1930년대부터 시작된 연구해역의 산업화, 도시화 현상을 반영하는1 것이라 사료된다.

• 생명과학회지
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• 제22권11호
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• pp.1435-1443
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• 2012

거제도 안골 골짜기와 뱃골 골짜기에서 식물 군락의 변화를 조사하였다. 알파-다양도와 감마-다양도는 서식지 단절의 크기와 정도에 따라 감소하였다. 우세종의 평균 종수도 서식지 단절에 따라 감소하였다. 상수리나무를 비롯한 참나무과 종들은 붉은토끼풀 같은 도입된 귀화식물의 증가에 따라 주요도가 감소하였다. 교란이 일어나지 않은 숲에서 성체 생존율의 몫이 증가함에 따라 탄력 예상치의 절대적 비는 2003년부터 2011년까지 증가하였다. 그러나 교란 집단에서는 비가 낮았다. Moran의 I값은 전반적으로 서식지 단절지역과 서식지전환 시기에서는 감소하였다. 결국 거제도에서 도시화에 따른 식물 군락은 환경이 교란되었을 때 보편종의 감소를 유발하였다.

• 교육시설 논문지
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• 제25권5호
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• pp.13-20
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• 2018

The purpose of this study is to provide a fundamental data and establish policies for the utilization of closed schools in Korea. The closed schools have been increased in Korea because not only the birth rate, and the number of students have been decreased, but also a greate number of people have moved to big cities or the elderly population is increasing. In this context, this research explores the current circumstance of Japan where experienced the similar phenomenon before Korea had. The results of this study are summarized as follows: The reason for the closed schools in Japan is a decrease in population due to the urbanization and reducing students themselves by aging. The recycling proportion of the closed schools is only approximately 62% in Japan. It means that fewer facilities have been recycled due to the transfer of the managemental departments and the lack of budgets for purchasing the closed schools. As the number of children decreases, but elderly people increases as the same time, it is necessary to positively examine the transition of the closed schools to new facilities for the elderly people. Even though the number of children had been declined, and it is recently turning back to an increasing of the residential children in 23 districts of Tokyo, there are still existing many closed schools. This phenomenon is caused by the decrease of the children and residential areas due to the aging and urbanization. For these reasons, there are many diverse demands for the practical and valuable recycling of the closed schools. However, it seems that there are few cases of successful disposal or transfer of management to other suitable ministry. Therefore, it is necessary for the closed schools to be remodeled the facilities required by current residents.

• 산업경영시스템학회지
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• 제45권3호
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• pp.197-203
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• 2022

Urban space expansion is an important symbol of the urbanization process and has always been an important topic in urban studies. In addition, for sustainable city management, it is important to identify factors that can influence, such as the driving force and direction of urban space expansion, from the stage of establishing an urban development plan. To understand these factors, by observing the expansion process of a specific city, it is possible to sufficiently observe how the urban spatial dimension changes. Through a series of processes, the spatial growth characteristics of the city are analyzed, and the influence and results of important factors are analyzed. For this purpose, this paper examines the changes in the city's outer boundary and land use structure through monitoring data on urban areas of 14 cities in Hunan Province, China from 2000 to 2016. Temporal and spatial regularity according to the urban space expansion of these cities were analyzed, and a preliminary assessment was made on whether the urban space expansion is coordinated with the urban population growth. The assessment result showed: (1) The urban space of most cities has been extended rapidly in 2000-2015 however, the rate and the intensity of urban space expanding has been declining. (2) The construction of the industrial park is the core driving force of the urban space expanding, and the change of the urban space structure is manifested as enclave city expansion because that the industrial park is usually far away from the city center. (3) The population agglomeration is another driving force of the urban space expanding. At this time, the urban space expanding is like boundary extension. (4) Except Changsha city, all of the cities has a high urbanization-area-growth elastic coefficient. It means that most of the cities should enhance the land use degree.

• 한국항행학회논문지
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• 제27권4호
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• pp.330-336
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• 2023

급격한 도시화는 전 세계적으로 도시화가 빠르게 진행되면서 교통 혼잡 및 환경오염, 소음 공해 등의 도시문제가 대두하고 있으며, 이러한 도시 집중화 현상으로 시간 낭비와 이로 인한 경제적 손실이 발생하고 있다. 이를 해결하기 위한 도심 항공 모빌리티(UAM; Urban Air Mobility)는 3차원 미래형 도시 교통수단으로, 도로·철도·개인교통수단과 연계한(Seamless) 교통서비스(MaaS; Mobility as a Service)로 스마트시티의 중요한 교통축으로 자리 잡을 전망이다. 그러나 2023년 7월 현재, UAM 운용을 위한 공역체계, 버티포트 설계, 항법, 통신 등과 관련된 연구는 활발히 이루어지고 있으나, 조종사 교육·훈련에 대한 개념 정립, 교육·훈련 프로그램에 대한 연구는 거의 이루어지고 있지 않은 것이 현실이다. 이에 본 논문에서는 미국과 유럽의 수직이·착륙(VTOL) 조종사 교육·훈련 프로그램을 SWOT 분석 방법을 통해, 국내 조종사 양성체계에 적합한 방안을 제시하고자 한다.

• 한국습지학회지
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• 제15권4호
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• pp.535-541
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• 2013

도시화로 인한 불투수층의 증가는 강우시 유출량 증가, 침투량 감소, 증발산량 감소 등을 유발시키고, 다량의 비점오염물질을 유출시킨다. 이러한 도시화에 의한 환경영향을 최소화하기 위하여 환경부는 2012년 이후 그린빗물인프라(Green Stormwater Infrastructure, GSI)기법을 정책적으로 도입하여 자연적 물순환을 구축하고 비점오염 유출저감을 저감하고자 한다. 본 연구에서는 자연적 물순환 구축을 통한 비점오염저감을 위하여 다양한 강우사상에 적용 가능한 침투여과기술을 개발하고자 한다. 기술의 실제 적용성 평가에 앞서 연구실 규모의 기술평가를 실시하였으며, 8회의 유량변화를 통한 평가를 수행하였다. 연구실 실험결과, 시설의 침투수, 저류수 및 유출수의 오염물질별 평균 EMC의 저감효율은 모든 오염물질 항목에서 50~90%의 범위로 높게 나타났는데 이는 높은 침투유량(약 35%)과 저류량(39%)에 의한 유출저감에 의해 나타났다. 침투여과시설의 지속적 효율은 막힘현상의 최소화로 나타나는데 본 기술의 공극 막힘현상은 누적 TSS 양이 $8.3{\sim}9.0kg/m^2$의 범위에 도달할 때 발생하였으며, 이 값은 타 연구결과에 비해 큰 값으로 나타나 장기간 높은 효율을 유지할 수 있는 것으로 분석되었다. 초기침강지를 설치하지 않은 상태에서도 시설로부터 유출되는 시료내 평균 입경크기는 $10{\mu}m$로 나타났기에 침강지를 설치할 경우 입자제거에 효과적일 것으로 판단된다.