Urban Tree Canopy Classification Using Remote Sensing

Seung Gyu Jeong,Hyeok Su Kwon,Dong Kun Lee,Jong Hoon Park 한국인간·식물·환경학회 2016 인간식물환경학회지 Vol.19 No.1

Tree canopy is a valuable component consisting of urban ecosystem. The purpose of this study was to classify urban tree canopy (UTC) by using high resolution imagery and object-oriented classification (OOC), which was used to classify the different land cover types. With an urban canopy mapping system based on OOC and Decision Tree Classification (DTC), a site mapping was carried out by merging spectral data of high resolution imagery. This methodological approach showed high classification accuracy to distinguish small patches and continuous UTC boundaries on the high resolution imagery. For shadow removal, decision tree classification with various environmental variables such as brightness channel and band combination could effectively work. Our proposed methodology can be successfully used for the assessment and restoration of fragmented urban ecosystem and offer an opportunity to obtain high classification accuracy for the distinction of UTC components in urban landscape areas.

일체형 링크 구조의 LP-EGR 밸브가 적용된 엔진의 NOx 저감 특성

정병규(Jeong Byeong Gyu),오광철(Oh Kwang Cheol),원장혁(Won Jang Hyeok),허형석(Heo Hyung Seok),배석정(Bae Seok Jeong),강필근(Kang Pil Geun),김호영(Kim Ho Young),박진한(Park Jin Han) 한국자동차공학회 2020 한국자동차공학회 부문종합 학술대회 Vol.2020 No.7

미세 살수판을 이용한 손 살균 디바이스 개발

정태혁(Tae-Hyeok Jeong),김규린(Gyu-Rin Kim),한정은(Jeong-Eun Han),양수원(Su-Won Yang),강태구(Tae-Koo Kang) 대한전기학회 2020 대한전기학회 워크샵 Vol.2020 No.7

Spin-orbit torque of W-V alloy based magnetic heterostructures

Jeong Kyu Lee,Gyu Won Kim,Taehyun Kim,Min Hyeok Lee,In Ho Cha,Jiung Cho,Young Keun Kim 한국자기학회 2022 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.2

Initial clinical outcomes of proton beam radiotherapy for hepatocellular carcinoma

Jeong Il Yu,Gyu Sang Yoo,Sungkoo Cho,Sang Hoon Jung,Youngyih Han,Seyjoon Park,Boram Lee,Wonseok Kang,Dong Hyun Sinn,Yong-Han Paik,Geum-Youn Gwak,Moon Seok Choi,Joon Hyeok Lee,Kwang Cheol Koh,Seung Woo 대한방사선종양학회 2018 Radiation Oncology Journal Vol.36 No.1

Purpose: This study aimed to evaluate the initial outcomes of proton beam therapy (PBT) for hepatocellular carcinoma (HCC) in terms of tumor response and safety. Materials and Methods: HCC patients who were not indicated for standard curative local modalities and who were treated with PBT at Samsung Medical Center from January 2016 to February 2017 were enrolled. Toxicity was scored using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Tumor response was evaluated using modified Response Evaluation Criteria in Solid Tumors (mRECIST). Results: A total of 101 HCC patients treated with PBT were included. Patients were treated with an equivalent dose of 62–92 GyE 10 . Liver function status was not significantly affected after PBT. Greater than 80% of patients had Child-Pugh class A and albumin-bilirubin (ALBI) grade 1 up to 3-months after PBT. Of 78 patients followed for three months after PBT, infield complete and partial responses were achieved in 54 (69.2%) and 14 (17.9%) patients, respectively. Conclusion: PBT treatment of HCC patients showed a favorable infield complete response rate of 69.2% with acceptable acute toxicity. An additional follow-up study of these patients will be conducted.

Incidental Finding of a Small Schwannoma Originating From the Recurrent Laryngeal Nerve During Thyroidectomy: A Case Report

Gyu Hwa Kim,Ho Jung Jeong,Jin Seok Lee,Hyeok Jun Yun,Yong Sang Lee,Hang-Seok Chang 대한내분비외과학회 2023 The Koreran journal of Endocrine Surgery Vol.23 No.4

Schwannomas are rare tumors that originate from peripheral nerves of the nerve root sheath, mostly in the head, neck, or extremities. Schwannomas originating from recurrent laryngeal nerves are rare. Herein, we report a case of a mass in the recurrent laryngeal nerve, expected to be a schwannoma, incidentally found during thyroidectomy in a patient with thyroid cancer. No surgical treatment was performed for the tumor, and the patient is currently under close observation without any symptoms before or after the surgery.

Spin-orbit torque properties of W-V alloy based magnetic heterostructures

Jeong Kyu Lee,Gyu Won Kim,Taehyun Kim,Min Hyeok Lee,In Ho Cha,Jiung Cho,Young Keun Kim 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.2

β-W is considered the most promising transition metal due to its outstanding charge-to-spin conversion efficiency. Despite this exceptional property, alloys based on β-W as a spin current generating layer have been rarely studied due to their lack of phase stability. This study examines various properties of W-V alloy layers in W100-xVx (5)/CoFeB (2.5)/MgO (1)/Ta (2) magnetic heterostructures with different W-V compositions. Samples were sputtered onto thermally oxidized Si wafers under a base pressure below 5 × 10<SUP>-9</SUP> Torr. Diverse W100-xVx compositions were fabricated by changing sputtering power densities of W and V targets during co-deposition. X-ray diffraction verified the existence of β-W up to a V content of 20 at%. It also confirmed that Co-V alloys are formed when V content exceeded 60 at%. Spin-orbit torque properties were analyzed by harmonics Hall measurement. Out of all the samples measured, the sample with W content of 80 at% and V of 20 at% showed the maximum damping-like torque efficiency of -0.45 ± 0.04. ξDL decreased drastically when V content exceeded 20 at% because phase transition from β-W to α-W occurred. We also fabricated heterostructures of W (5)/CoFeB (0.9)/MgO (1)/Ta (2) and W80V20 (5)/CoFeB (0.9)/MgO (1)/Ta (2) to obtain perpendicular magnetic anisotropy. These samples were used to acquire optical microscope images and determine switching current densities. We utilized Magneto-Optic Kerr Effect microscope to observe and obtain current-induced spin-orbit torque switching images for the W80V20 alloy-based sample. The change in the contrast of the images successfully depicted the magnetization switching of the ferromagnetic CoFeB layers. The switching current (current density) was 11 mA (2.2 × 10<SUP>7</SUP> A cm<SUP>-2</SUP>) and 6 mA (1.2 × 10<SUP>7</SUP> A cm<SUP>-2</SUP>) for β-W and W80V20, respectively. The switching current is clearly reduced when W80V20 is used instead of pristine W. We hope that this work will play as a key role in the field of spintronics in the future. 〈그림 본문참조〉

Growth of CH₃NH₃PbI₃ cuboids with controlled size for high-efficiency perovskite solar cells

Im, Jeong-Hyeok,Jang, In-Hyuk,Pellet, Norman,Grä,tzel, Michael,Park, Nam-Gyu Nature Publishing Group, a division of Macmillan P 2014 Nature nanotechnology Vol.9 No.11

Perovskite solar cells with submicrometre-thick CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> or CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3–</SUB><SUB>x</SUB>Cl<SUB>x</SUB> active layers show a power conversion efficiency as high as 15%. However, compared to the best-performing device, the average efficiency was as low as 12%, with a large standard deviation (s.d.). Here, we report perovskite solar cells with an average efficiency exceeding 16% and best efficiency of 17%. This was enabled by the growth of CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> cuboids with a controlled size via a two-step spin-coating procedure. Spin-coating of a solution of CH<SUB>3</SUB>NH<SUB>3</SUB>I with different concentrations follows the spin-coating of PbI<SUB>2</SUB>, and the cuboid size of CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> is found to strongly depend on the concentration of CH<SUB>3</SUB>NH<SUB>3</SUB>I. Light-harvesting efficiency and charge-carrier extraction are significantly affected by the cuboid size. Under simulated one-sun illumination, average efficiencies of 16.4% (s.d. ± 0.35), 16.3% (s.d. ± 0.44) and 13.5% (s.d. ± 0.34) are obtained from solutions of CH<SUB>3</SUB>NH<SUB>3</SUB>I with concentrations of 0.038 M, 0.050 M and 0.063 M, respectively. By controlling the size of the cuboids of CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> during their growth, we achieved the best efficiency of 17.01% with a photocurrent density of 21.64 mA cm<SUP>–2</SUP>, open-circuit photovoltage of 1.056 V and fill factor of 0.741.

정보기술과 자원·환경의 관리

정규호(Jeong, Gyu-Ho),허남혁(Heo, Nam-Hyeok) 한국공간환경학회 2005 공간과 사회 Vol.24 No.-

본 논문은 생태위기의 지구화와 경제의 세계화가 만들어내는 급속한 변화의 흐름 속에서 지속가능한 자원관리의 중요성에 주목하면서, 특히 정보기술이 자원 이용 및 관리 측면에 가져다 줄 새로운 가능성과 기회요인을 포착하여 지속가능 한 사회로 나아가기 위한 방향과 정책적 과제들을 거시적으로 살펴보는 데 초점을 맞추고 있다. 우리나라의 자원·환경관리 정책은 사후처방적 수준에서 사전예방적 수준의 초기 단계로 접어들었다. 국가경제규모와 국민의 소비수준에 비추어 생태학적 자립기반이 매우 취약한 상황에서 앞으로 보다 적극적인 자원·환경관리 노력이 필요 하다. 지난 10여 년 동안 국민들의 환경에 대한 관심이 높아지고 지속가능한 발전이 국가 정책과 기업의 생산 활동에 중요한 가치로 자리 잡아 왔지만 인식과 실천 간의 괴리 현상이 여전히 크기 때문이다. 따라서 우리나라가 지속가능한 사회로 가기 위해서는 보다 강한 지속가능성을 정착시키기 위한 기술 혁신과 함께 사회제도 영역의 생태적 재구조화(ecological restructuring)를 통한 질적 전환 노력이 병행될 필요가 있다. 그리고 이러한 변화에 있어 인터넷, GIS, RS 등 정보기술의 발달은 학습과 성찰을 통한 사전예방적 관리, 자율과 참여를 통한 민주적 관리, 소통과 협력을 통한 통합적 관리의 가능성을 높여 줌으로써, 지속가능한 자원·환경관리 체계를 구축하는데 중요한 역할을 할 것으로 기대된다. 그러나 정보기술의 사용에 있어 그 경로에 대한 무분별한 수용보다는 사회적인 논의와 합의를 통해 정보기술을 활용할 때에만 정보기술이 가져올 부작용을 최소화할 수 있다. This article focuses on the importance of sustainable resource management, especially new possibilities and opportunities of resource use and management brought by IT, considering policy implications and the direction for sustainable society on macro-scale. The resource and environmental management policy of Korea has stepped into the early stage of precaution. We need more positive efforts for resource and environmental management considering our fragile ecological self-sufficiency comparing with our economic scale and consumption level. Although the growth of environmental consciousness and the positioning of the concept of sustainable development in the national policy and corporate production activities in Korea during the last decade, the gap between the consciousness and practices is still wide. For Korea to be more sustainable society, we need ecological restructuring of social institution sphere for qualitative transformation as well as technological innovations for stronger sustainability. the development of IT such as internet, GIS, RS is expected to play the significant role for constructing sustainable resource and environmental management system by promoting the possibility of precautional management through learning and reflection, democratic management through autonomy and participation, integrative management through communication and cooperation. However, the negative side-effects of IT could be minimized only through social discussion and consensus rather than undiscriminated acceptance.

Highly Efficient Monolithic Dye-Sensitized Solar Cells

Kwon, Jeong,Park, Nam-Gyu,Lee, Jun Young,Ko, Min Jae,Park, Jong Hyeok American Chemical Society 2013 ACS APPLIED MATERIALS & INTERFACES Vol.5 No.6

<P>Monolithic dye-sensitized solar cells (M-DSSCs) provide an effective way to reduce the fabrication cost of general DSSCs since they do not require transparent conducting oxide substrates for the counter electrode. However, conventional monolithic devices have low efficiency because of the impediments resulting from counter electrode materials and spacer layers. Here, we demonstrate highly efficient M-DSSCs featuring a highly conductive polymer combined with macroporous polymer spacer layers. With M-DSSCs based on a PEDOT/polymer spacer layer, a power conversion efficiency of 7.73% was achieved, which is, to the best of our knowledge, the highest efficiency for M-DSSCs to date. Further, PEDOT/polymer spacer layers were applied to flexible DSSCs and their cell performance was investigated.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2013/aamick.2013.5.issue-6/am302974z/production/images/medium/am-2012-02974z_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am302974z'>ACS Electronic Supporting Info</A></P>