배치형과 연속흐름형에 의한 토양 중 RDX의 아임계 분해특성 비교연구

최재헌,이환,이철효,김주엽,박정훈,조영태,Choi, Jae-Heon,Lee, Hwan,Lee, Cheol-Hyo,Kim, Ju-Yup,Park, Jeong-Hun,Jo, Young-Tae 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.6

The purpose of this study is to compare the degradation characteristics by subcritical water of RDX contaminated soil using batch mode and dynamic mode devices. First, upon application of RDX contaminated soil, RDX treatment efficiency was increased with increasing the temperature in both modes. At 150℃, the treatment efficiency was 99.9%. RDX degradation efficiency got higher with lower ratio of solid to liquid. However, the treatment efficiency in the dynamic mode tended to be decreased at a certain ratio of solid to liquid or lower. The treatment efficiency was increased when it took longer time for the reactions in both modes. As the results of analysis on concentration of treated water after subcritical water degradation, the RDX recovery rate of dynamic and batch modes at 150℃ was 10.5% and 1.5%, respectively. However, both modes showed very similar recovery rates at 175℃ or higher. RDX degradation products were analyzed in treated water after it was treated with subcritical water. According to the results, RDX degradation mechanism was mostly oxidation reaction and reduction reaction was partially involved. Therefore, it suggested that most of RDX in soil was degraded by oxidation of subcritical water upon extraction. According to this result, it was found that both batch and dynamic modes were very effectively applied in the treatment of explosive contaminated soil.

단롤법으로 제조한 AISI 310 스테인레스강의 급냉 조직에 관한 연구

최재헌,오명석,조성석,이용호 ( J . H . Choi,M . S . Oh,S . S . J,Y . H . Lee ) 한국열처리공학회 1996 熱處理工學會誌 Vol.9 No.1

Melt-quenching of steels leads to various metallographic effects such as refinement of grain size, extension of the solid solubility of carbon and alloying elements, and is expected to improve the mechanical properties of conventional steels. Furthermore, this technique is a useful method for producing sheet directly from liquid state. And it will lend itself to development as a continuous cast process which offers significant savings in energy and product costs. The purpose of this study is to present the microstructures of melt-quenched austenitic stainless steels. As the results of this study. the morphology of melt-quenched microstructure show that the roll contact area is columnar structure. and the free surface area is dendrite structure. As the line speed increases, the ratio of d_(colunnar)/d_(total) increases from 0.12 to 0.60, but the ribbon thickness decreases from 150㎛ to 30㎛.

저개발 국가로부터의 여성결혼이주와 결혼중개업체의 특성

최재헌 ( Jae Heon Choi ) 한국도시지리학회 2007 한국도시지리학회지 Vol.10 No.2

논문 : 용산 미군기지의 문화유산 가치와 도시발전 방향

최재헌 ( Jae Heon Choi ),남영우 ( Young Woo Nam ) 한국도시지리학회 2014 한국도시지리학회지 Vol.17 No.2

본 연구는 용산 미군기지가 갖는 문화유산 가치를 장소성을 가지는 유산으로 파악하여 지리적 환경과 도시발달사를 고려한 지역 변천에 초점을 맞추어 용산 미군기지의 상징성과 문화유산 가치를 고찰해보고 바람직한 개발 방향을 논의하였다. 용산 미군기지 일대는 13세기 몽골군의 병참기지로부터, 조선시대의 강촌, 도성관문, 물류유통기지로서의 성격을 거쳐, 일제강점기에 군사경관이 형성되고 외세에 의한 식민기지로서 특징이 나타나며, 해방 이후에는 군사경관이 유지된 성역화된 군사기지, 금단의 경관으로서의 특징을 보인다. 현재에는 과거의 경관요소가 그대로 남아있는 화석화된 경관(fossil landscape)으로서 외세에 의한 천이의 공간이기도 하다. 용산 미군기지의 발전 방향은 개발위주, 보존위주, 절충적 입장에서 접근이 가능하다. 그러나 향후 용산의 다양한 층위를 고려하여 유산 가치를 보존하는 방안을 강구하고 세계유산으로 등재 조건을 충족할 수 있는 완전성과 진정성을 확보하며, 지역 상징성을 유지하면서 교육적 가치와 정체성 확보를 위한 활용 가치를 극대화할 수 있어야 한다. This paper intends to discuss the various directions of urban development of Yongsan military base, highlighting the heritage value in the context of urban development and regional changes in each time period including Joseon Dynasty, open port period, Japanese Colonial Times and after the liberalization. Yongsan military base has shifted from military storage yard in the 13th century, to river port as a gateway city in Joseon Dynasty, to a military base during the Japanese Colonial Times, and has been continuously keeping a forbidden military space for the US forces after the liberalization. It can be defined as a fossil landscape, functioning as a space of succession for foreign military forces in different time periods. Either development oriented, preservation oriented or eclectic approach can be adopted for future development. However, it needs to figure out the most appropriate way of both preserving cultural heritage for multi-layered structure of Yongsan military base and confirming integrity and authenticity for possible inscription on the World Heritage List in the context to keep symbolic meaning as well as to enhance place identity and educational value for future generation.

NPC 인버터의 DC-link 커패시터 전류 리플 감소를 위한 전압 변조 방법 비교 평가

최재헌(Jae-Heon Choi),최의민(Ui-Min Choi) 전력전자학회 2021 전력전자학술대회 논문집 Vol.2021 No.11

DC-link 커패시터는 전력 변환 시스템에서 신뢰성이 취약한 소자 중 하나이다. 커패시터의 수명은 동작 온도가 상승할수록 감소하며 전류 리플에 의한 손실은 커패시터 온도를 상승시키는 주요 원인이다. 따라서 NPC 인버터의 DC-link 커패시터의 전류 리플을 감소시켜 커패시터의 수명을 향상시키기 위한 다양한 연구들이 수행되고 있다. 그러나 전류 리플을 감소시키기 위한 전압 변조 방법들은 인버터 출력 품질을 저하시키는 단점이 존재한다. 본 논문에서는 3-레벨 NPC 인버터의 DC-link 커패시터의 전류 리플을 감소시키기 위해 제안된 공간 벡터 전압 변조 방법들을 비교 분석한다. 제안된 방법들이 적용되었을 때, 커패시터 전류 리플에 의한 전력 손실을 분석하고 이에 의한 예측 수명과 NPC 인버터 출력 전류의 THD에 미치는 영향을 비교 분석한다.

세계유산적 가치의 관점에서 본 산성도시 남한산성의 경관 분석

최재헌 ( Jae Heon Choi ),이혜은 ( Hae Un Rii ) 한국도시지리학회 2013 한국도시지리학회지 Vol.16 No.1

This paper analyzed the multi-layered features of Namhansanseong‘s landscape both by times and functions form the viewpoint of outstanding universal value as world heritage, which are assumed to be composed of military defensive, governing and folks attributes. Form military attributes, Namhansanseong was a valley-crossing mountain city that utilized natural terrains for defensive facilities as well as a protype mo9del for East Asian fortress technology. Form governing attributes, it was functioned as both a temporary capital city and administrative center for Gwangju-gun. Moreover, Namhansanseong was a representative of cultural tradition of Korea, self-reliance spirit and territorial protection spirit of Buddhism in Joseon Dynasty. Analyzing 94 landscape components in Namhansanseong landscape revealed dominant military defensive layer followed by governing and folks layer in numbers. The initial military landscape was formed during the reign of King Injo in 17th century while major military defensive components after introduction of gun powder artillery were completely added in the reign of King Sukjong in 18th century Other folks components including pavilions were dominantly built in 19th century of King Sunjo. 본 논문은 세계유산적 가치의 관점에서 산성도시 남한상성의 경관요소를 군사경관, 통치경관, 민속경관으로 구분하고 시대별, 기능별 다층위성을 규명하는 것을 목적으로 하였다. 군사적 측면에서 남한산성은 자연 지세를 방어시설의 일부로 활용한 포곡식 신성이며, 동아시아 성곽 축성술의 발달을 보여주는 모델이다. 통치적 측면에서는 임시 수도이면서 읍치로서의 행정 중심지 기능을 수행하였고, 민속적 측면에서 주민들의 전통과 호국 불교사상, 조선의 자주정신이 발현된 곳이다. 산성도시로서의 남한산성 경관은 시대별 변청상과 기능별 경관요소가 중첩되어 있으며, 94개 경관요소를 분석하면 군사-통치-미속 경관 순으로 그 특징이 나타난 다. 시대적 층위에서는17세기 인조 때에 군사 경관요소의 기반이 형성되었고, 1681년 숙종 재위기에 화포에 대응한 군사 경관요소의 설치가 완비되었으며, 순조 이후에는 누정 등 민속 경관요소가 주로 형성되었다.

태양광 시스템의 미션 프로파일 고려한 3-레벨 NPC 인버터의 DC-link 커패시터 신뢰성 비교 분석

최재헌(Jae-Heon Choi),최의민(Ui-Min Choi) 전력전자학회 2022 전력전자학회 논문지 Vol.27 No.6

논문 : 중기 밀턴의 종교적, 윤리적, 정치적 이상주의 -그의 영웅적 소네트와 산문의 관련성을 중심으로

최재헌 ( Jae Hun Choi ) 한국영어영문학회 2010 영어 영문학 Vol.56 No.1

내면의 갈등과 신과의 대화: 존 던의 종교시와 산문

최재헌 ( Jae Hun Choi ) 한국밀턴과 근세영문학회(구 한국밀턴학회) 2006 중세근세영문학 Vol.16 No.1

에이드리엔 리치의 레즈비언/페미니스트 시와 시학

최재헌(Choi Jae-Hun) 신영어영문학회 2002 신영어영문학 Vol.21 No.-

Since her first collection of poetry, A Change of World (1951), appeared, Adrienne Rich has been a major and influential figure in the literary world. As a poet, feminist thinker, and political activist, she has been not only providing some of the best-written poetry of recent times, but also has written some of the most scholarly books of feminist criticism, such as Of Woman Born: Motherhood as Experience and Institution (1976) and On Lies, Secrets and Silence (1979). Her essays provide an important context for her poems. Rich’s style and subject matter have undergone significant changes. From the 1970s, Rich began to identify herself as a radical feminist and develop a distinctively woman’s voice. Rich also became aware of the need for a poetic language to explore and rename the unique experiences of women hitherto silenced or unrepresented in literature. So she attempted to shape a language capable of articulating the maternal and feminine experience. Feminist scholars responded in various ways to Rich’s controversial essay “Compulsory Heterosexuality and Lesbian Existence” (1980), but it has become a cornerstone of feminist and lesbian theorizing. She not only offered a critical analysis of heterosexuality, but reconceptualized lesbian love as natural and normal. Now a politically active lesbian, Rich has accordingly narrowed her poetic perspective to accommodate that position. Rich is both controversial and celebrated for her activism, and developed into not only one of the most widely read but also the most widely resisted woman poets of the century.