First Record of Subgenus Pronocerodes Plavilstshikov (Coleoptera: Cerambycidae: Ropalopus) from Korea

이승현,오승환,이민혁,승진배,이승환,Lee, Seunghyun,Oh, Seunghwan,Lee, Minhyeuk,Seung, Jinbae,Lee, Seunghwan Korean Society of Applied Entomology 2021 한국응용곤충학회지 Vol.60 No.3

하늘소아과 검정삼나무하늘소속의 미기록아속인 호리검정삼나무하늘소아속(신칭)에 속하는 Ropalopus (Pronocerodes) aurantiicollis Plavilstshikov, 1940의 한반도 분포를 처음으로 보고한다. 형태적 기재와 사진, 국내 검정삼나무하늘소속의 검색표를 함께 제공한다. The subgenus Pronocerodes Plavilstshikov (Coleoptera: Cerambycidae: Cerambycinae) is reported from Korea for the first time with a species of Ropalopus (Pronocerodes) aurantiicollis Plavilstshikov, 1940. The morphological information is provided with a key to the Korean Ropalopus and photographs of an adult specimen.

MOCVD를 이용한 금속 촉매 종류에 따른 β-Ga₂O₃ 나노 와이어의 제작과 특성

이승현,이서영,정용호,이효종,안형수,양민,Lee, Seunghyun,Lee, Seoyoung,Jeong, Yongho,Lee, Hyojong,Ahn, Hyungsoo,Yang, Min 한국결정성장학회 2017 한국결정성장학회지 Vol.27 No.1

Metal organic chemical vapor deposition(MOCVD) 방법을 이용하여 금속 촉매에 따른 ${\beta}-Ga_2O_3$ 나노 와이어의 제작과 특성에 대해 연구하였다. 본 연구의 성장 조건에서 ${\beta}-Ga_2O_3$ 나노 와이어의 성장이 가능한 금속 촉매는 Au, Cu 그리고 Ni이 있었으며 각 금속 촉매로 성장한 나노 와이어는 성장률과 형상에 많은 차이가 있었다. Ni 촉매 성장의 경우에는 Vapor-Solid(VS) 과정이 ${\beta}-Ga_2O_3$ 나노 와이어 성장의 주된 메커니즘이고 Au, Cu 촉매 성장의 경우에는 Vapor-Liquid-Solid(VLS) 과정이 주된 성장 메커니즘 임을 확인할 수 있었다. 또한, 촉매의 종류에 따라서 ${\beta}-Ga_2O_3$ 나노 와이어의 광학적 특성도 다르게 나타나는 것을 확인할 수 있었다. 반면, 동일한 성장 조건에서 Ti, Ag 그리고 Sn 금속은 나노 와이어 성장을 위한 촉매로 작용하지 못하였다. 본 연구에서는 금속 촉매에 따른 나노 와이어의 성장 가능 여부와 성장한 나노 와이어의 특성 변화가 금속 촉매의 녹는 점, 금속- Ga의 공융 점과 관련이 있음을 상태도와 연관 지어 밝혀내었다. Catalytic synthesis and properties of ${\beta}-Ga_2O_3$ nanowires grown by metal organic chemical vapor deposition are reported. Au, Ni and Cu catalysts were suitable for the growth of $Ga_2O_3$ nanowires under our experimental conditions. The $Ga_2O_3$ nanowires grown by using Au, Ni and Cu catalysts showed different growth rates and morphologies in each case. We found the $Ga_2O_3$ nanowires were grown by the Vapor-Solid (VS) process when Ni was used as a catalyst while the Vapor-Liquid-Solid (VLS) was a dominant process in case of Au and Cu catalysts. Also, we found nanowires showed different optical properties depend on catalytic metals. On the other hand, for the cases of Ti, Sn and Ag catalysts, nanowires could not be obtained under the same condition of Au, Cu and Ni catalytic synthesis. We found that these results are related to the different characteristics of each catalyst, such as, melting points and phase diagrams with gallium metal.

Data-driven health condition and RUL prognosis for liquid filtration systems

이승현,Seungju Lee,Kwonneung Lee,Sangwon Lee,Jaemin Chung,김창완,윤장혁 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.4

Because the clogging of filters leads to degradation and failure of mechanical systems, it is important to assess the health condition of a filter and predict its remaining useful life (RUL). Despite prior studies of liquid filtration systems, adequate attention has not been paid to data-driven health condition and RUL prognosis. Therefore, this study suggests a datadriven prognosis approach for liquid filtration systems. We define a health index (HI) for the filter under study and then predict HI values from the degradation point to the end-of-life using recurrent neural network algorithms, thereby yielding the filter’s RUL. As a result, the bidirectional LSTM achieved the best performance, and the RUL measured through HI prediction was close to the actual RUL. The proposed approach can be used for the maintenance of liquid filtration systems in various industries.

홍삼·백년초 복합물이 관절염 개선에 미치는 효과

이승현,이창현,김홍준,김영식,신민지,김지현,마상용,이세연,권진,오찬호,Lee, Seung-Hyeon,Lee, Chang-Hyun,Kim, Hong-Jun,Kim, Young-Sik,Shin, Min-Ji,Kim, Ji-Hyun,Ma, Sang-Yong,Lee, Se-Youn,Kwon, Jin,Oh, Chan-Ho 대한한의학방제학회 2021 大韓韓醫學方劑學會誌 Vol.29 No.2

Objectives : This study was conducted to evaluate the efficacy of a complex mixture of natural substances of ginseng and baeknyeoncho on the arthritic rats. Methods : In vitro experiments were conducted to ensure the stability of the complex. After setting toxicity and concentration by MTT assay, the antioxidant effect was measured through DPPH and ABTS radical scavenging activity. To confirm the anti-inflammatory effects of the complex, levels of nitric oxide (NO) and pro-inflammatory cytokines (IL-1β, TNF-α) were measured in LPS-treated macrophage cell lines (RAW264.7). We injected monosodium iodoacetate (MIA) 50 μl (60 mg/ml) into knee joints of rats to induce osteoarthritis. The rats were divided into three groups (normal (n=5), control (n=5), and OR (n=5) group). The control group consumed 2 mg/kg of physiological saline once a day for 4 weeks, and the OR group was mixed at a concentration of 416.5 mg/kg of Baengnyeoncho (O) and 208.25 mg/kg of red ginseng (R) and ingested 1 mL each 5 days a week. Results : This complex increased the DPPH and ABTS radical scavenging rate. The complex decreased NO production and pro-inflammatory cytokine production of macrophages. In the OR group, the secretion of cytokine in serum was decreased. In histopathological examination, the joint tissue of the composite showed less damage to the synovial membrane, cartilage, and fibrous tissue than the control group. Conclusions : As a result of this study, natural complexes have antioxidant, anti-inflammatory and cartilage protection effects. Therefore, we expect the complex to be effective in treating osteoarthritis.

양성자 치료 시 방사선 작업 종사자에게 미치는 방사선 피폭에 대한 평가

이승현,장요종,김태윤,정도형,최계숙,Lee, Seung-Hyun,Jang, Yo-Jong,Kim, Tae-Yoon,Jeong, Do-Hyung,Choi, Gye-Suk 대한방사선치료학회 2012 대한방사선치료학회지 Vol.24 No.2

목 적: 기존의 광자선을 이용한 선형가속기와는 달리, 양성자 치료의 경우 물질과의 상호작용으로 발생되는 중성자를 비롯한 여러 핵종 등으로 인해 다량의 이차방사선이 생성되기 때문에 방사선 작업 종사자의 피폭은 더욱 주의 깊은 관심이 필요하다. 이에 방사선 측정 시에 널리 이용되고 있는 열형광선량계를 이용하여 방사선 작업 종사자의 피폭정도를 평가하고 이를 토대로 양성자 치료 시 방사선 피폭선량에 관한 기초 자료를 제시하고자 한다. 대상 및 방법: 본원의 양성자 치료실에서 근무한 방사선 작업 종사자를 대상으로 열형광선량계 뱃지를 이용해 피폭현황을 측정한 데이터를 비교했다. 양성자의 빔 라인 주변에서 발생하는 이차방사선의 신체부위별 피폭선량 분포를 알아보고자 신체부위(외안각, 목, 유두점, 배꼽, 등, 손목)에 가로, 세로가 각각 3 mm인 정사각형 모양의 열형광선량계를 부착하여 일일 8시간의 근무시간동안 유지하도록 하였고 총 80시간 측정하여 평균 데이터를 얻었다. 그리고 치료실 내 공간적인 방사선량의 분포를 보기 위하여 빔 사출구, PPS (Patient Positioning System), Pendant, 차폐체보관장, DIPS (Digital Image Positioning System) Console, 출입통로에 각각 열형광선랑계를 부착하고 일일 근무시간 동안의 평균 방사선량을 측정하였다. 결 과: 방사선 작업 종사자의 열형광선량계 뱃지로 측정된 피폭량을 조사한 결과 분기별 평균 0.174 mSv, 연평균 0.543 mSv로 나타났고 신체부위별로 측정한 결과에서 가장 많은 피폭량을 보인 곳은 목이였으며 가장 적은 피폭량을 보인 곳은 등(양견갑골 상각을 이은 선의 중간 지점)으로 나타났다. 작업 동선에 따른 공간적 방사선량을 알아본 결과에서는 빔 사출구 근처에서 상대적으로 높게 나타났고 거리가 멀어짐에 따라 줄어들었다. 결 론: 적은 양의 피폭일지라도 동일 장소에서 장기 근무하게 되면 피폭 누적량은 증가할 수밖에 없고 특정 부위의 누적량은 건강상의 위험을 가져다 줄 수도 있다. 그러므로 국제 방사선 방어 위원회가 권고하는 ALARA의 원칙에 따라 가능한 합리적으로 감소시킬 수 있도록 스스로 개인별 피폭관리에 철저를 기하고 피폭을 최소화시키는데 최선의 노력을 다해야 할 것이다. Purpose: Unlike the existing linear accelerator with photon, proton therapy produces a number of second radiation due to the kinds of nuclide including neutron that is produced from the interaction with matter, and more attention must be paid on the exposure level of radiation workers for this reason. Therefore, thermoluminescence dosimeter (TLD) that is being widely used to measure radiation was utilized to analyze the exposure level of the radiation workers and propose a basic data about the radiation exposure level during the proton therapy. Materials and Methods: The subjects were radiation workers who worked at the proton therapy center of National Cancer Center and TLD Badge was used to compare the measured data of exposure level. In order to check the dispersion of exposure dose on body parts from the second radiation coming out surrounding the beam line of proton, TLD (width and length: 3 mm each) was attached to on the body spots (lateral canthi, neck, nipples, umbilicus, back, wrists) and retained them for 8 working hours, and the average data was obtained after measuring them for 80 hours. Moreover, in order to look into the dispersion of spatial exposure in the treatment room, TLD was attached on the snout, PPS (Patient Positioning System), Pendant, block closet, DIPS (Digital Image Positioning System), Console, doors and measured its exposure dose level during the working hours per day. Results: As a result of measuring exposure level of TLD Badge of radiation workers, quarterly average was 0.174 mSv, yearly average was 0.543 mSv, and after measuring the exposure level of body spots, it showed that the highest exposed body spot was neck and the lowest exposed body spot was back (the middle point of a line connecting both scapula superior angles). Investigation into the spatial exposure according to the workers' movement revealed that the exposure level was highest near the snout and as the distance becomes distant, it went lower. Conclusion: Even a small amount of exposure will eventually increase cumulative dose and exposure dose on a specific body part can bring health risks if one works in a same location for a long period. Therefore, radiation workers must thoroughly manage exposure dose and try their best to minimize it according to ALARA (As Low As Reasonably Achievable) as the International Commission on Radiological Protection (ICRP) recommends.

중심장액맥락망막병증에서 다른 눈의 중심와아래 맥락막 두께

이승현,정혜원,김형찬,Seung Hyen Lee,Hyewon Chung,Hyung Chan Kim 대한안과학회 2012 대한안과학회지 Vol.53 No.7

Purpose: To determine the relationship between subfoveal choroidal thickness of fellow eyes and choroidal vascular hyperpermeability in unilateral central serous chorioretinopathy (CSC). Methods: Thirty patients with unilateral CSC and 28 normal subjects underwent enhanced depth imaging spectral-domain optical coherence tomography to evaluate bilateral subfoveal choroidal thickness. The subfoveal choroidal thickness was measured from the outer RPE border to the inner sclera border. Choroidal vascular hyperpermeability was visualized with indocyanine green angiography (ICGA) and analyzed. Results: The mean subfoveal choroidal thickness in the affected eyes (439.6 ± 136.5 μm) was significantly thicker than that in fellow eyes (340.0 ± 103.3 μm, p = 0.002), and both showed statistically significant difference compared with normal subjects (266.5 ± 111.5 μm, p < 0.001, p = 0.019). The subfoveal choroidal thickness of fellow eyes with choroidal vascular hyperpermeability was 370.0 ± 176.5 μm, which differed significantly (p = 0.037) from the choroid without choroidal vascular hyperpermeability. The choroidal thickness of acute CSC was 441.6 ± 118.6 μm, and that of chronic CSC was 454 ± 166.5 μm, a difference that was not statistically significant (p = 0.676). Conclusions: The subfoveal choroid with hyperpermeability was thicker than that without hyperpermeability on ICGA in the fellow eyes of patients with unilateral CSC. Enhanced depth imaging spectral-domain optical coherence tomography can indirectly evaluate the effects of choroidal hyperpermeability by noninvasively measuring the choroidal thickness. J Korean Ophthalmol Soc 2012;53(7):982-987

분리형 부재 옹벽 설계 프로그램 개발

이승현,윤찬영,Lee. Seung-Hyun,Yune. Chan-Young 한국방재학회 2011 한국방재학회논문집 Vol.11 No.5

본 연구에서는 지압형 보강재를 갖는 분리형 부재 옹벽의 설계에 있어 검토해야 할 세부 검토항목을 살펴보고 설계 프로그램을 개발하였다. 분리형 부재 옹벽의 설계시 세부 설계내용은 외적 안정성 검토, 내적 안정성 검토 그리고 국부적 안정성 검토의 세 가지로 대별할 수 있다. 설계 프로그램에 반영된 외적 안정성 검토는 통상적인 옹벽에 대한 검토와 큰 차이는 없다. 내적 안정성 검토에서 고려해야 할 보강재의 인장파괴에 대한 검토와 인발에 대한 검토 세부 사항을 살펴보았고 국부적 안정성 검토에서 고려해야 할 보강재와 전면부재 사이의 연결강도에 대한 검토와 전면부재의 접촉면 사이의 전단강도에 관련한 벌징(bulging)에 대한 검토 세부 사항을 살펴보고 이를 개발된 프로그램에 구현하였다. 또한, 설계 예를 제시하여 입력자료와 검토결과를 나타냄으로써 개발된 프로그램의 이해를 증진시키고자 하였다. In this study, detailed design requirements for segmental retaining wall (SRW) which were concerned with external stability, internal stability, and local stability were investigated and a computer program for designing the SRW was developed as well. There are little differences in the estimation of the external stability between the algorithm of the developed program and the conventional method for the design of the SRW. Methods for accounting tension failure and pullout of the reinforcement were incorporated in the developed program, which were essentials in the internal stability. Methods for accounting the connection strength between a reinforcement and a facing block and for accounting the bulging concerned with the shear strength of the interface between two blocks were also incorporated in the developed program, which are essentials in the local stability. Design example run by the developed program is presented in order to enhance the knowledge of the developed program.

흙-못치기 공법을 적용한 사면의 거동 비교

이승현,Lee. Seung-Hyun 한국방재학회 2011 한국방재학회논문집 Vol.11 No.4

흙-못치기 공법을 적용한 사면에 대해 법면을 숏크리트로 처리한 사면과 프리캐스트 콘크리트 전면판을 적용한 사면의 경우로 나누어 실물 현장시험이 수행되었다. 현장시험결과 얻은 하중-침하곡선을 비교해 볼 때 전면판을 적용한 경우 하중지지능력이 우수함을 알 수 있었다. 현장시험시 재하판에 가해진 총하중에 대해 재하판의 침하양상은 전면판을 적용한 경우 연성기초가 모래지반에 놓이는 경우와 같은 침하분포를 보인다. 숏크리트를 적용한 경우, 재하판의 침하량은 유사한 총하중 수준에서 전면판을 적용한 침하량에 비해 크고 부등침하의 경향도 크다. 전면판 적용시 보강면에 설치한 하중계에 의한 하중분포와 변형률계에 의한 계측결과, 재하판의 침하양상 그리고 경사계에 의한 수평변위양상을 종합적으로 고려해 볼 때 전면판을 적용할 경우 숏크리트를 적용할 때보다 국부적인 변위를 억제하고 보다 넓은 보강면에 하중을 분산시키는 것으로 생각된다. Full scale field load tests were conducted on two kinds of slopes reinforced with soil nail. One of the two slope is the slope with surface treated by shotcrete. The other slope has a surface placed by precast concrete panel. By comparing load-settlement curves, load bearing capacity for the case of pecast concrete panel was bigger than that for the case of shotcrete. Settlemet distribution of loading plate for the case of precast concrete panel was similar to that for the case in which flexible footing lies on sand. Settlement for the case of shotcrete was bigger than that for the case of the precast concrete panel and also was the differential settlement. By considering overall the test data of all the measurements related with load cell, strain gauge, settlement of loading plate and inclinometer, precast concrete panel has the advantage of load sharing in larger area and restriction of local displacement to the shotcrete treated case.

테마파크를 실감미디어 개발을 통해 구현하였을 때 발전 가능성 - 소외 공간을 중점으로 탐구

이승현,Lee, Seung-Hyun 국제문화기술진흥원 2022 The Journal of the Convergence on Culture Technolo Vol.8 No.6

As the theme of a theme park space with limited space emerged as a keyword, many experiments and research were conducted in the field. In the domestic market, not only the creation of new spaces, but also the need to develop marginalized spaces and seek complementary points through new interpretations of actual spaces, but they show physical limitations. This study newly redefined and analyzed the concept of space by approaching and interpreting virtual space as a new space. By exploring real-world examples and analyzing the results, we also derive the results that the possibility of realistic media in the virtual world is an exemplary alternative to complementing the expansion and limitations of the space. Realistic media has a wide range of content provision in selective development such as AR and VR, and the theme park's characteristic of providing various contents for quarterly concepts even if the development budget and time are small, which has a significant impact on the development of realistic media. Currently, theme parks are attracting countless majors and officials related to realistic media through metaverse. As it is attracting attention in such a new market, we look forward to seeing a lot of research and experiments in the project.

이기종의 모바일 IP 네트워크에서 끊김없는 프록시 기반의 핸드오프 기법

이승현,신동렬,정종필,Lee, Seung-Hyun,Shin, Dong-Ryeol,Jeong, Jong-Pil 한국정보처리학회 2012 정보처리학회논문지 C : 정보통신,정보보안 Vol.19 No.1

향후의 차세대 무선 네트워크(NGWN) 환경에서는 음성을 비롯한 모든 정보들이 ALL-IP 망에서 동작하게 될 것이며, 현재는 이러한 과도기로서 IP 네트워크에서 사용자로 하여금 끊김없는 서비스를 유지하기 위한 망의 중요성 및 이기종 네트워크 간의 핸드오프에 대한 중요성이 커지고 있다. 이에 본 논문에서는 NGWN에서 여러 기법 중 핸드오프 성능을 높일 수 있는 끊김없는 PMIPv6 기반의 프록시 모델을 이용한 SePH를 제안한다. SePH의 특징으로는 핸드오프 과정 중 탐색 과정을 줄임으로서 끊김없는 IP 기반의 이동성을 효율적으로 지원할 수 있다. 제안한 SePH 기법의 성능 평가는 현재 이동성 관리 프로토콜에 비해 처리량, 핸드오프 지연시간, 패킷손실 및 시그널링 오버헤드 등의 이동성 관리 측면에서 QoS 향상을 보여준다. In Next Generation Wireless Networks (NGWN), lots of information, such as voice and video data, will be used in All-IP networks. It is important note that seamless service for users and handoff between heterogeneous networks must be taken into account in such environments. Therefore, in this paper, we propose a SePH(Seamless Proxy based Handoff) using PMIPv6-based proxy model which is enable to improve the performance of handoff in NGWN. The SePH can efficiently support seamless and IP-based mobility by reducing the search process. The performance results show that our proposed scheme outperforms in terms of QoS (Quality of Service) such as throughput, handoff latency, packet loss, and signaling overhead comparing to the existing schemes.