• Journal of Korean Society of Environmental Engineers
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• v.32 no.7
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• pp.690-698
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• 2010

Contamination of groundwater resources by organic chemicals has become an issue of increasing environmental concern. Surfactant-enhanced aquifer remediation (SEAR) is widely recognized as one of the most promising techniques to remediate organic contaminations in-situ. Solutions of surfactant or surfactant with polymer are used to dramatically expedite the process, which in turn, may reduce the treatment time of a site compared to use of water alone. In the design of surfactant-based technologies for remediation of organic contaminated aquifers, it is very important to have a considerable analysis using extensive numerical simulations prior to full-scale implementation. This study investigated the formation and flow of microemulsions during SEAR of organic-contaminated aquifer using the finite difference model UTCHEM, a three-dimensional, multicomponent, multiphase, compositional model. The remediation process variables considered in this study were the sequence of injection fluids, the injection and extraction rate, the concentrations of polymer in surfactant slug and chase water, and the duration of surfactant injection. For each variable, temporal changes in injection and production wells and spatial distributions of relative saturations in the organic phase were compared. Cleanup time and cumulative organic recovery were also quantified. The study would provide useful information to design strategies for the remediation of nonaqueous phase liquid-contaminated aquifers.

• Proceedings of the Korean Professional Engineer Association Conference
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• 1995.12b
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• pp.30-48
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• 1995

서울시는 국가의 수도로서 이제 6n년의 역사를 맞이하였다. 뛰어난 산수와 자연 경관을 가진 서울시의 자연은 근세이후 도시의 발전에 따른 점차적으로 훼손되어 왔으며, 특히 1960년대 이후의 도시성장기에 시행된 개발 위주의 도시 정책은 공원 녹지의 잠식을 가속화시켜 본래의 자연은 양적, 질적 측면에 많은 피해가 발생되었다. 또한 도시 정책의 부분으로서 공원 녹지 정책은 개발 위주의 도시 정책에 밀려 제기능을 발휘 할 수 없었으며, 정책에 있어서도 목표와 미래 방향에 대한 뚜렷한 비전을 제시하지 못하였다. 현재 공원 녹지와 관련된 정책 환경을 볼 때, 각종의 도시개발 사업, 지방 자치제 시행에 따를 도시의 난 개발은 부족한 공원녹지를 더욱 잠식하는 위협요소가 되고 있으며, 토지수요에 대한 공급의 한계 상황에 직면해 있는 시점에서 개발론자 들은 공원 녹지를 개발의 주요대상으로 인식하는 자세를 견지하고 있다. 그러나 최근 들어 지구 환경의 문제의 대두, 환경에 대한 시민의 관심, 정책 집행자들의 환경 보전과 관리의 움직임이 나타나기 시작하고 있어 서울시의 공원 녹지의 미래 전망을 밝게 해주는 긍정적인 요소가 되고 있다. 2000년대를 바라본 현시점에서 도시의 기간 요소로서 공원 녹지는 단지 존재만의 가치가 아니라 적정한 기능을 부여하고 이용의 활성화를 통한 공원 녹지의 새로운 탄생이 요구되고 있다. 이것은 공원 녹지정책 측면에서 공원 녹지의 양적 측면에서의 풍요로움과 질적 측면에서의 기능성의 회복과 도시 구성적 측면에서의 공원 녹지의 네트워크의 구성이라는 3가지의 정책 이슈를 제기한다. 양적 측면에서 녹의 풍요로움을 확보하기 위해서는 기존의 공급 지표 위주의 정책보다는 공원 녹지의 총량적인 관리 체제를 통한 전 도시적 차원의 공원녹지 관리 시스템이 필요하며, 공원 녹지로서 잠재 가치를 가지고 있는 새로운 유형의 공원 녹지의 조성과 각종 개발사업에 대한 공원 녹지의 잠식 방지를 위한 명확한 사회적인 공감대의 형성이 요구된다. 질적 측면에서는 공원 녹지의 기능성의 회복이라는 측면과 시대에 부합되는 새로운 기능 및 가치의 부여가 필요하며, 이를 위해서는 공원의 매력, 공원의 시설기능 증진, 녹지의 질의 향상 및 녹지 가치의 증진에 대한 다양한 시책이 요구된다. 구성적 측면에서는 공원녹지의 개별적 존재보다는 공원 녹지를 상호간 유기적인 계통을 확보하여 공원 녹지의 네트워크를 형성하여 도시 속의 산재된 고립된 섬으로서의 공원 녹지가 아닌 시민생활에 늘 가까이 있는 생활 속의 공원녹지로 재편되어야 한다. 이러한 정책의 의제는 양적 측면에서 보전(CONSERVATION)과 창출(CREATION), 질적 측면에서 쇄신(RENOVATION)과 복구(RESTORATION), 그리고 구성적 측면에서 공원 녹지의 연결(CONNECTION)과 시민 참여에 의한 운동(MOVEMENT)이라는 정책 개념의 구현을 통해 가능하다. 이러한 정책 개념과 의제를 가지고 서울시 공원 녹지 정책을 구체화시키기 위해서 푸르름의 새로운 탄생이라는 기치 아래 풍요로운 서울, 사랑 받는 공원, 생활 속의 녹지의 3대 목표, 공원 녹지의 보전, 잠재 공원 녹지의 창출, 공원의 활성화, 녹지의 복구, 경관 보전 및 복구, 공원 녹지의 네트워크, 도시 녹화의 7대 과제를 설정하고 미시설 공원 녹지 집행, 개발 사업시 공원 녹지의 확보, 환경 녹지의 총량 보호 관리, 도시 소공원 개발, 역사 문화 공원 조성, 하천 공간 복원, 공원 시설 기능 개선, 이용 프로그램 개발, 공원 관리 개선, 환경 피해 녹지의 회복, 도시 환경 림 조성, 녹지 기능 증진, 도시 자연 경관 보전, 공원 녹지체계 구성, 공원 녹지 공급 균형, 주변 환경 녹화, 가로 녹화의 17개 시책을 제안하였다. 이러한 정책사업의 원활한 추진을 위해서는 기존의 관주도의 일방적인 공원 녹지 행정이 아닌 시민의 참여를 통한 시민이 함께 하는 정 책 사업의 추진이 요구되며, 특히 민간 부문의 적극적 인 참여를 유도하기 위한 방안이 동시 에 강구되어야 한다. 또한 공공에서는 정 책 집행을 위한 조직과 행정의 개편, 예산의 확보 방안을 적극적으로 검토해야 한다. 현재 서울시는 지방자치제 시행에 따라 시 행정에 있어 많은 변화가 예고되고 있으며, 공원 녹지는 새로운 환경 변화에 부합되는 적절한 도시요소가 될 것으로 추정된다. 서울시 하천 복개의 금지, 하천공간의 복원에 대한 움직임, 환경 녹지 복구를 위한 사업의 시행, 민간부문의 환경 운동의 활성화 등 바람직 한 현상이 전개되고 있어, 공원 녹지는 미래의 도시 관리 에 있어 주요 관심사가 될 것이다.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.1
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• pp.33-52
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• 2022

The History and Culture Park and the Lee Kun-hee Donation Hall will be built in Songhyeon-dong, Seoul. Political games from the Joseon Dynasty to the present greatly influenced the historicity of Songhyeon-dong. However, place analysis was limited to changes in landowners and land uses rather than a historical context. Therefore, this study analyzed the context in which the placeness of Songhyeon-dong changed according to the emergence of cultural hegemony using the perspective of modern cultural geography and comparative history. As a result of the analysis, cultural hegemony in historical transitions, such as Sinocentrism, maritime expansion, civil revolutions, imperialism, nationalism, popular art, and neoliberalism, was found to have created new intellectuals in Bukchon, including Songhyeon-dong, and influenced social systems and spatial policies. In this social relations, the placeness of Songhyeon-dong changed as follows. First, the founding forces of Joseon created pine forests as Bibo Forests to invocate the permanence of the dynasty. In the late Joseon dynasty, it was an era of maritime expansion, and as Joseon's yeonhaeng increased, a garden for the Gyeonghwasejok, who enjoyed the culture of the Qing dynasty, was built. Although pine forests and gardens disappeared due to the development of housing complexes as the population soared during the Japanese colonial era, Cha Gyeong's landscape aesthetics, which harmonized artificial gardens and external nature, are worth reinterpreting in modern times. Second, the wave of modernization created a new school in Bukchon and a boarding house in Songhyeon-dong owned by a pro-Japanese faction. Angukdongcheon-gil, next to Songhyeon-dong, was where thinkers who promoted civil revolution and national self-determination exchanged ideas. Songhyeon-dong, the largest boarding house, served as a residence for students to participate in the March 1st Movement and was the cradle of the resulting culture of student movements. The appearance of the old road is preserved, so it is a significant part of the regeneration of walking in the historic city center, connecting Gwanghwamun-Bukchon-Insadong -Donhwamunro. Third, from the cultural rule of the Government General of Joseon to the Military Government, Songhyeon-dong acted as a passage to western culture with the Joseon Siksan Bank's cultural housing and staff accommodations at the U.S. Embassy. Ancient and contemporary art coexisted in the surrounding area, so the modern and contemporary art market was formed. The Lee Kun-hee Donation Hall is expected to form a cultural belt for citizens with the gallery, Bukchon Hanok Village, the Craft Museum, and the Modern Museum of Art. Discourses and challenges are needed to recreate the place in harmony with the forests, gardens, the street of citizens' birth, history and culture park, the art museum, and the surrounding walking network.

• The korean journal of orthodontics
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• v.36 no.5
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• pp.339-348
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• 2006

Objective: With development of the skeletal anchorage system, orthodontic mini-implant (OMI) assisted on masse sliding retraction has become part of general orthodontic treatment. But compared to the emphasis on successful anchorage preparation, the control of anterior teeth axis has not been emphasized enough. Methods: A 3-D finite element Base model of maxillary dental arch and a Lingual tipping model with lingually inclined anterior teeth were constructed. To evaluate factors influencing the axis of anterior teeth when OMI was used as anchorage, models were simulated with 2 mm or 5 mm retraction hooks and/or by the addition of 4 mm of compensating curve (CC) on the main archwire. The stress distribution on the roots and a 25000 times enlarged axis graph were evaluated. Results: Intrusive component of retraction force directed postero-superiorly from the 2 mm height hook did not reduce the lingual tipping of anterior teeth. When hook height was increased to 5 mm, lateral incisor showed crown-labial and root-lingual torque and uncontrolled tipping of the canine was increased.4 mm of CC added to the main archwire also induced crown-labial and root-lingual torque of the lateral incisor but uncontrolled tipping of the canine was decreased. Lingual tipping model showed very similar results compared with the Base model. Conclusion: The results of this study showed that height of the hook and compensating curve on the main archwire can influence the axis of anterior teeth. These data can be used as guidelines for clinical application.

• Maritime Security
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• v.4 no.1
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• pp.57-82
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• 2022

The objective of this treatise is to explore the limitations of the current navy manpower utilization system and the ways to improve it from the perspective of Generation Z. As Generation Z, following Millennials, has finally come of age, this new group is constituting a gradually greater proportion of military personnel. Due to the typical characteristics of naval operations, the harmony between Millennials and Generation Z, which is differentiated from Generation X in view of dispositions and traits, is one of the essential issues to be discussed. Generally, in a naval vessel, there are numerous pieces of equipment necessary to carry out a wide range of missions and a large number of crew members who operate them with consistent levels of fighting power. This is all while members are living together within the narrow space throughout the 24 hours of each day. Under such particular circumstances, any inter-generational conflicts may have a disruptive effect on the successful accomplishment of naval missions. Currently, new generations of military personnel are facing social difficulties in different aspects compared with the previous generations, and also have different viewpoints on the military. In this regard, in order to foster true harmony between generations, it is considered necessary to take a closer look at the inter-generational differences from their respective standpoints and to examine whether the military organization has taken adequate steps to respond to such changes. Accordingly, Chapters 1 and 2 cover the environments in which Millennials and Generation Z were raised during their childhood to young adulthood, which are distinct from those of older generations, their viewpoints formed based on such backgrounds, and the need to resolve various conflicts between generations. In Chapter 3, the current actions taken by overseas military powers to enhance the coexistence with Generation MZ are analyzed to find the significant implications they had. Chapter 4 examines the operation environments specific to the navy; identifies the potential barriers to achieving harmony between generations by assessing the current status of personnel utilization in the Korean navy in terms of the seaman, petty officer, and the officer, as well as policy; and outlines the solutions to drive harmony. Finally, Chapter 5 emphasizes the need to establish a genuine empathy between generations based on the understanding of unique inter-generational characteristics. This section also discusses the importance of addressing difficulties in utilizing technology-centered naval manpower, and forecasts a scenario of a naval organization that resolves the problem of utilizing naval personnel and the inter-generational conflicts in the future.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.1
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• pp.207-244
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• 2015

Aviation safety is the stage in which the risk of harm to persons or of property damage is reduced to, and maintained at or below, an acceptable level through a continuing process of hazard identification and risk management. Many accidents and incidents have been taking place since 2014, while there had been relatively safer skies before 2014. International civil aviation community has been exerting great efforts to deal with these emerging issues, thus enhancing and ensuring safety throughout the world over the years. The Preamble of the Chicago Convention emphasizes safety and order of international air transport, and so many Articles in the Convention are related to the safety. Furthermore, most of the Annexes to the Convention are International Standards and Recommended Practices pertaining to the safety. In particular, Annex 19, which was promulgated in Nov. 2013, dealing with safety management system. ICAO, as law-making body, has Air Navigation Commission, Council, Assembly to deliberate and make decisions regarding safety issues. It is also implementing USOAP and USAP to supervise safety functions of member States. After MH 370 disappeared in 2014, ICAO is developing Global Tracking System whereby there should be no loophole in tracking the location of aircraft anywhere in world with the information provided by many stakeholders concerned. MH 17 accident drove ICAO to install web-based repository where information relating to the operation in conflict zones is provided and shared. In addition, ICAO has been initiating various solutions to emerging issues such as ebola outbreak and operation under extreme meteorological conditions. Considering the necessity of protection and sharing of safety data and information to enhance safety level, ICAO is now suggesting enhanced provisions to do so, and getting feedback from member States. It has been observed that ICAO has been approaching issues towards problem-solving from four different dimensions. First regarding time, it analyses past experiences and best practices, and make solutions in short, mid and long terms. Second, from space perspective, ICAO covers States, region and the world as a whole. Third, regarding stakeholders it consults with and hear from as many entities as it could, including airlines, airports, community, consumers, manufacturers, air traffic control centers, air navigation service providers, industry and insurers. Last not but least, in terms of regulatory changes, it identifies best practices, guidance materials and provisions which could become standards and recommended practices.