Novel Transfer-Printing Process for Block Copolymer Nanopatterns Using Chemically Modified Graphene

고영천,김은지,선승원,김시몬,오영택,황준표,김봉훈 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

Among the various transfer-printing processes, a simple and primitive technique involves retrieving ultrathin nanomaterials, such as polymers, 2D materials, and quantum dots, floating on the surface of a liquid. In particular, this method has significant limitations as it is largely affected by the surface energy of a receiver substrate and inevitably generates numerous wrinkles during the printing process. In this work, we investigate a novel transfer-printing process for metal nanopattern arrays on chemically modified graphene (CMG) films using a block copolymer (BCP) nanotemplate and polydimethylsiloxane (PDMS) stamp. A metal nanopattern array fabricated with BCP lithography on a CMG film was thus successfully transferred to nonplanar (i.e., rough or curved) surfaces. The new transcription process method for nanomaterial thin films presented in this study is expected to be utilized for the development of various next-generation electronic/energy devices as it can be applied to flexible substrates or boards with complex 3D shapes.

뉴스테이 공급에 따른 주택시장 반응과 효과: 인천 미추홀구와 수원 권선구 지역에 관한 연구

고영천(Young Chon Koh),신종화(Jong Hwa Shin) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.5

본 연구는 2015년 도입된 뉴스테이 공급에 따른 입주 시점 전후에 대한 실증적 분석을 통해 뉴스테이 공급으로 인한 주택시장의 반응과 효과에 대한 정책적 시사점을 도출하고자 한다. 본 연구는 뉴스테이 사업이 적용된 인천 미추홀구 도화동, 수원 권선구 오목천동 지역과 미시행 지역은 유사지역인 인천 미추홀구 숭의동/주안동, 수원 권선구 호매실동/고색동으로 한정하여 입주일 기준으로 전후 12개월 동안의 공급에 따른 주택가격 변화에 대하여 분석하였다. 연구방법은 정책효과를 측정하는 대표적인 방법인 이중차분법을 활용하였다. 뉴스테이를 도입한 인천 미추홀구에서는 입주일을 기점으로 시행 지역인 도화동과 미시행 지역인 숭의동을 비교한 결과, 미시행 지역 가격보다 시행 지역의 가격수준이 높아 뉴스테이가 도화동에 도입되면서 인근지역(숭의동) 아파트 가격을 하강시키는 것으로 나타났다. 수원 권선구에서도 입주일을 기점으로 시행 지역인 오목천동과 미시행 지역인 고색동을 비교분석한 결과, 뉴스테이가 오목천동에 도입되면서 인근지역(고색동) 아파트 가격을 하강내지는 안정시키는 것으로 나타났다. 이러한 결과는 기업형 임대주택의 공급물량이 많아지면 주변 지역의 주택 가격을 하향 안정화 시킬 수 있는 것을 시사한다. This study analyzed the housing market before and after the New Stay movement which was introduced in 2015. In this study, the territories having a New Stay Project and non-involved territories were analyzed based on the apartment price changes according to supply for 12 months before and after the movement date. This study used the difference-in-differences statistical technique. A comparison was carried out in Michuhol-gu, Incheon between Dowha-dong where a New Stay Project was executed, and Sungeui-dong where no project was executed, based on the movement date. It was seen that the price level in the former territory was higher than the latter demonstrating that the introduction of the New Stay Project in Dowha-dong lowered the apartment prices nearby (Sungeui-dong). A comparison in Gwonseon-gu, Suwon between Omogcheon-dong where a New Stay Project was executed and Gosaek-dong where there was no such project, based on the movement date showed that the introduction of the New Stay Project in Omogcheon-dong seemed to lower or stabilize the apartment prices nearby (Gosaek-dong). These results imply that the apartment prices in nearby areas can be stabilized if the supply volume of company-type rental houses is increased.

민간주택분양가 상한제 정책효과분석

고영천(Koh, Young-Chon) 한국도시행정학회 2021 도시 행정 학보 Vol.34 No.2

본 연구는 민간주택 분양가상한제 정책 시행을 기준으로 아파트의 가격 변화를 살펴봄으로써 분양가 상한제 정책이 공동주택가격에 미치는 영향을 파악하여 합리적 · 효율적 정책 방향을 모색하고자 한다. 이를 위해 정책 시행일 기준인 2020년 7월 28일 전후 2개월 동안 강남구, 서초구, 송파구, 강동구의 강남 4구와 마포구, 용산구, 성동구의 주택 거래 자료를 사용하여 정책의 효과를 분석하였다. 민간주택 분양가상한제 도입의 효과는 이중차분법 분석모형을 적용하여 추정하였다. 분석결과, 주택규모와 한강지역에 상관없이 전체적으로 정책 미시행 지역보다 정책 시행 지역에서, 정책 시행 전보다 시행후에 아파트 가격 수준이 높아졌다. 그러나 실제 정책의 효과는 가격수준을 하락시키는 것으로 나타났는데, 주택규모에 따라서는 60㎡ 이하인 소형주택에서만, 한강 기준으로는 북쪽 지역에서만 정책이 가격수준을 하락시키는 것으로 나타나, 중 · 대형 주택과 한강이남 지역에서는 분양가 상한제의 가격 안정 효과가 없음을 확인할 수 있다. 결과적으로 민간주택 분양가상한제 정책은 소형 주택과 한강 북쪽에서는 유의미하게 분석할 수 있지만, 시장의 특성이 상이한 중 · 대형 규모의 아파트와 한강 남쪽에서는 유의하지 않다고 할 수 있다. This study is aimed to review the price change of apartments upon implementation of price ceiling policy for private houses so as to understand the effects of the policy on the apartment price and to seek the rational and efficient direction of the policy. To do so, the effects of the policy was analyzed for 2 months before and after the implementation date of the policy on July 28, 2020 using the house trading data in 4 Gangnams including Gangnam-gu, Seocho-gu, Songpa-gu, and Gangdong-gu; Mapo-gu; Yongsan-gu; and Seongdong-gu. The introduction effects of the price ceiling policy for private houses were predicted by the analysis model of difference-in-differences. Analysis results showed that price level of apartments in the policy implemented territories after the policy implementation had been raised compared to that in the policy unimplemented territories before its implementation regardless of the size of houses and location of Han-River. However, the actual effects of the policy showed to lower the price level only in small sized houses not bigger than 60㎡ and northern area to Han River, which confirmed no effect of the price ceiling policy on the price stabilization in mid-to-large sized houses and southern area to Han River. As a result, the price ceiling policy for private houses can be significant in small sized houses and northern area to Han River, but not in mid-to-large sized houses and southern area to Han River that have different market characteristics.

Single Nodular Pulmonary Amyloidosis: Case Report

이승현,고영천,정종필,박찬우,서석호,김종택,박대원,박철민,문승기,조신형,김세미,정아론 대한결핵및호흡기학회 2015 Tuberculosis and Respiratory Diseases Vol.78 No.4

Amyloidosis is defined as the presence of extra-cellular deposits of an insoluble fibrillar protein, amyloid. The pulmonary involvement of amyloidosis is usually classified as tracheobronchial, parenchymal nodular, or diffuse alveolar septal. A single nodular lesion can mimic various conditions, including malignancy, pulmonary tuberculosis, and fungal infection. To date, only one case of nodular pulmonary amyloidosis has been reported in Korea, a case involving multiple nodular lesions. Here, we report and discuss the case of a patient having single nodular amyloidosis.

Hierarchical Self-Assembly of Thickness-Modulated Block Copolymer for Controlling Orientations Inside Silicon Trenches

오영택,이정우,김시몬,고영천,박신,이세기,김봉훈 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

We study the orientation and ordering of nanodomains of a thickness-modulated lamellar block copolymer (BCP) thin film at each thickness region inside a topological nano/micropattern of bare silicon wafers without chemical pretreatments. With precise control of the thickness gradient of a BCP thin film and the width of a bare silicon trench, we successfully demonstrate (i) perfectly oriented lamellar nanodomains, (ii) pseudocylindrical nanopatterns as periodically aligned defects from the lamellar BCP thin film, and (iii) half-cylindrical nanostructure arrays leveraged by a trench sidewall with the strong preferential wetting of the PMMA block of the BCP. Our strategy has an advantage in fabricating diverse nanopatterns simultaneously compared to conventional BCP lithography utilizing chemical pretreatments. The proposed self-assembly nanopatterning process can be used in next-generation nanofabrication processes with minimized fabrication steps for low-cost manufacturing techniques.

Multimodal Sensing with a Three-Dimensional Structure

박준현,진호준,이정우,고영천,정민규,선승원,김봉훈 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

Sensors that reproduce the complex characteristics of cutaneous receptors in the skin have important potential in the context of artificial systems for controlled interactions with the physical environment. Multimodal responses with high sensitivity and wide dynamic range are essential for many such applications. This report introduces a simple, three-dimensional type of microelectromechanical sensor that incorporates monocrystalline silicon nanomembranes as piezoresistive elements. The technology provides high sensitivity measurements with millisecond response times, as supported by quantitative simulations. The fabrication and assembly processes allow scalable production of interconnected arrays of such devices with capabilities in spatiotemporal mapping. Integration with wireless data recording and transmission electronics allows operation with standard consumer devices.

Three-Dimensional Silicon Electronic Systems Fabricated by Compressive Buckling Process

이수언,진호준,성한상,고영천,박준현,정민규,김봉훈 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

The work reported here establishes further capabilities for directly embedding high-performance electronic devices into the resultant 3D constructs based on silicon nanomembranes as the active materials in custom devices or microscale components released from commercial wafer sources. Systematic experimental studies and theoretical analysis illustrate the key ideas through varied 3D architectures, from interconnected bridges and coils to extended chiral structures, each of which embed n-channel Si NM MOSFETs, Si NM diodes, and p-channel silicon MOSFETs. Examples in stretchable/deformable systems highlight additional features of these platforms. These strategies are immediately applicable to other wide-ranging classes of materials and device technologies that can be rendered in two-dimensional layouts, from systems for energy storage, to photovoltaics, optoelectronics, and others.