COVID-19가 건설프로젝트 리스크에 미치는 영향

이재현,이성현,이동훈,Lee, Jae-Hyun,Lee, Seong-Hyeon,Lee, Donghoon 한국건설안전학회 2021 한국건설안전학회 논문집 Vol.4 No.1

COVID-19, which is currently in vogue, is a pandemic with the largest number of deaths since the establishment of the "World Health Organization". It is also expected to have a significant impact on countless construction projects. After COVID-19 hit the construction industry, the risk that they needed to cover, decreased every year. However, the prolonged COVID-19 increased the risks of air delays, material supply, and economic losses. The exact measurements will be needed to be identified and the risks of the current construction projects must have a mitigated risk with a greater proportion. Therefore, the purpose of this study is to analyze and identify the risks that have influenced construction projects to the domestic construction companies due to COVID-19. Based on the risks of the previous construction projects, risk case studies, and risks related to COVID-19, are extracted through surveys, weights. Each risk factor are calculated based on the AHP analysis technique. Thus, it is expected that the results of the risk research on construction projects will change due to COVID-19. It will be presented to cope with the current situation and later pandemic situations.

두툽상어 췌장에 출현하는 내분비세포의 면역조직화학적 연구

이재현,이남수,이형식,김종법,Lee, Jae-hyun,Lee, Nam-soo,Lee, Hyeung-sik,Kim, Jong-beom The Korean Society of Veterinary Science 1991 대한수의학회지 Vol.31 No.1

The pancreatic endocrine cells of the cat-shark, S. torazame, were studied using immunohistochemical method. Five kinds of endocrine cells (glucagon-, somatostatin-, insulin-, 5-HT-and BPP-immunoreactive cells) identified in this study. The chracteristic findings of the distributions of five immunoreactive cells were as follows. Glucagon-immunoreactive cells were detected as clustering group in the epithelia of the interlobular duct and singly the pancreatic acini, respectively. Insulin -immunoreactive cells were moderately observed in the epithelia of the interlobular duct or in the periphery of the islet. Somatostatin-immunoreactive cells were distributed in single or mass groups in the epithelia of the interlobular duct and the exocrine gland of the pancreas. A very few 5-HTimmunoreactive cells were seen in the periphery of the islet and the acini of the pancreas-BPP-immunoreactive cell was singly located in the periphery of the pancreatic islet, but GAS/CCK-and Chromogranin-immunoreactive cells were not found in this study.

고슴도치 위점막의 내분비세포에 관한 면역조직화학적 연구

이재현,이형식,이남수,김종범,Lee, Jae-hyun,Lee, Hyeung-sik,Lee, Nam-soo,Kim, Jong-beom 대한수의학회 1991 대한수의학회지 Vol.31 No.1

한국산 고슴도치의 위점막에 분포하는 내분비세포에 대해 면역조직화학적으로 관찰하였던바, gastrin, somatostatin, 5-HT, glucagon, BPP, motilin, GIP 등 7종의 면역반응세포들이 동정되었으며, 이들 세포들의 부위별 분포와 출현빈도의 특정은 다음과 같다. Gastrin 면역반웅세포는 유문부에서만 아주 다수로 출현하였으며, somatostatin 면역반응세포는 유문부에서 다수, 분문부와 위저부에서는 중등도의 출현올 볼 수 있었다. 5-HT 면역반응세포는 분문부와 유문부에서 다수, 위저부에서는 중등도로 출현하였다. glucagon 면역반응세포는 위저부에서 소수로 그리고 유문부에서 극히 소수로 출현하였고, BPP 면역반응세포는 유문부에 다수로, 위저부에 중등도로 분문부에 소수로 분포하였다. motilin 면역반응세포는 유문부와 위저부에서 소수 또는 극소수로 출현하였으며, GIP 면역반응세포는 유문부에서만 소수의 분포를 볼 수 있었다.

식민지 시대 민족 지성 최현배의 사상과 국어 연구의 배경 - 민족주의적 낭만주의자로서의 사상을 중심으로 -

이재현 ( Jae Hyun Lee ) 한민족문화학회 2003 한민족문화연구 Vol.12 No.-

한국산 고슴도치 분문부와 위저부의 내분비세포에 관한 전자현미경적 연구

이재현,이형식,이남수,김종범,Lee, Jae-hyun,Lee, Hyeung-sik,Lee, Nam-soo,Kim, Jong-beom The Korean Society of Veterinary Science 1990 大韓獸醫學會誌 Vol.30 No.4

한국산 고슴도치의 분문부와 위저부에 있어서 내분비세포를 전자현미경적으로 관찰하였던 바 EC, ECL, $D_1$, G 및 A-1ike 세포 등 5종의 세포가 동정되었다. EC 세포는 높은 전자밀도의 다형태성 과립을 가지며, 과립내에는 더 높은 천자밀도의 dense body가 보였고, 과립의 크기는 170~500nm였다. ECL 세포는 원형 또는 난원형의 과립을 가지며, 과립 내용물은 전자밀도가 높고 편재하거나 공포상으로 출현하였고, 과립의 크기는 220~450nm였다. $D_1$ 세포는 원형의 과립을 가지며, 과립의 전자밀도는 낮거나 중등도였고, 과립의 크기는 140~400nm였다. G 세포는 원형 또는 난원형의 과립을 가지며, 중등도의 전자밀도를 나다내는 과립은 내용물과 한계막 사이에 좁은 halo를 보였고, 과립의 크기는 200~400nm였다. A-like 세포는 원형의 과립을 가지며, 이들 과립은 높은 전자밀도를 나타내었고, 내용물과 한계막은 밀착하였으며, 과립의 크기는 170~260nm였다. Endocrine cells in the cardiac and fundic regions of the Korean hedgehog were studied ultrastructurally. Five types of endocrine cells classified as EC, ECL, $D_1$. G and A-like cells were identified in these regions. EC cells contained pleomorphic granules, 170~500nm in diameter, with high electron density and highly dense bodies in a dense matrix. ECL cells were characterized by the presence of round or oval granules, 220~450nm in diameter, with high electron density. Some granules of ECL cells showed a small amounts of contents or empty. $D_1$ cells contained round and relatively small granules, 140~400nm in diameter, with low to moderate electron density. G cells were characterized by the presence of round or oval granules, 200~400nm in diameter, with moderate electron density. Some granules of these cells showed a narrow halo between the limiting membrane and the granular matrix. A-like cells contained round granules, 170~260nm in diameter, With high electron density. The granules of these cells showed homogeneous matrix surrounded by the tight membrane.

과도한 마모를 보이는 환자에서, 임플란트를 활용해 수직 고경을 증가시키며 shortened dental arch 개념을 적용한 보철 수복 증례

이재현,김태수,이철원,이원섭,이수영,Lee, Jae Hyun,Kim, Tae Su,Lee, Chul Won,Lee, Won Sup,Lee, Su Young 대한치과보철학회 2016 대한치과보철학회지 Vol.54 No.1

Excessive occlusal wear can result in unacceptable damage to the residual teeth structure, anterior guidance and masticatory function. An 86-year-old man presented with worn dentition and anterior deep bite due to loss of the posterior support. Two implants covered by Korean national health insurance, fixed partial denture and direct composite resin were used to restore the dentition, instead of removable prosthesis. The occlusal vertical dimension was increased by 2 mm in the premolar area and shortened dental arch concept was applied. This treatment was a less expensive alternative to full-mouth rehabilitation with positive esthetic and functional outcomes after 7 months of follow-up.

랫트에서 Clonorchis sinensis 감염이 간 oval cell 의 증식에 미치는 영향

이재현,윤병일,박민경,김신나,이준상,주경환,김한종,Lee, Jae-Hyun,Yoon, Byung-Il,Park, Min-Kyung,Kim, Shin-A,Lee, Joon-Sang,Joo, Kyoung-Hwan,Kim, Han-Jong 한국수의병리학회 1998 한국수의병리학회지 Vol.2 No.2

The prevalence of primary liver carcinoma (PLC) is relatively high in Clonorchis sinensis (CS) endemic areas in Korea. PLC is a malignant tumor which can be subclassified into hepatocellular carcinoma and cholangiocarcinoma(CC). CC has been associated with clonorchiasis, but it is unclear whether clonorchiasis is associated with hepatocarcinogenesis. This experiment was designed to investigate relationships between clonorchiasis and early changes of hepatocarcinogenesis. Sixteen Sprague-Dawley rats weighing 150g were divided into two groups of 8 rats in each. All rats were fed choline-devoid(CD) diet for 4 weeks. Group 1 was given 0.015-0.020% diethylnitrosamine(DEN) as drinking water for 1 week. After one week, the rats were treated orally with 1% N-acetylaminofluorene(AAF) (5 times per week for 2 weeks). Group 2 was treated equally to group 1 except for CS infection during AAF treatment. Two rats in each group were sacrificed at 4th, 5th, 6th and 7th week of the experiment. Livers were stained with OV -6, proliferating cell nuclear antigen(PCNA) and GST-p. Results were as follows: Group 2 livers showed more oval cell proliferation in parenchyma and portal areas at the 4th, 5th, 6th and 7th weeks than did livers of group 1 (p<0.01). PCNA was mostly localized in oval cell populations, rather than hepatocytes and biliary cells. The ratio of oval cells to hepatocytes was much higher in group 2 than in group l(p<0.01 The ratio of hepatocytes to biliary cells is higher in group 2 than in group 1 (p<0.05), More group 2 acidophilic foci reacted to GST-p monoclonal antibody than in the noninfected group. It appeared that CS infection promoted potentially precancerous acidophilic foci and oval cell proliferation.

한국재래산양 갑상샘에 있어서 Calcitonin면역 반응세포의 개체발생

이재현,구세광,이형식,Lee, Jae-hyun,Ku, Sae-kwang,Lee, Hyeung-sik 대한수의학회 1996 대한수의학회지 Vol.36 No.3

The development of calcitonin, serotonin(5-HT) and bovine chromogranin (BCG)-immunoreactive cells was investigated in the thyroid glands of Korean native goat from fetus to adult, using an immunohistochemical method. Moderate number of calcitonin-immunoreactive cells were present in the thyroid glands from 1 month to 6 months after birth, whereas a few in the adult. They were not present in the thyroid glands of fetus and 1 day after birth. A number of 5-HT- and BCG-immunoreactive cells were present in the thyroid glands of Korean native goat from fetus to adult. They were increased in number with age. BCG-immunoreactive cells were weakly reacted in fetus and 1 day after birth, while these cell were strongly stained from 1 month to adult. These findings suggest that calcitonin-, 5-HT- and BCG-immunoreactive cells were present in the thyroid gland of Korean native goat.

임베디드 시스템과 무선 랜을 이용한 이동성이 높은 재고단위의 위치관리 시스템 설계 및 구현

이재현,권경희,Lee, Jae-Hyun,Kwon, Kyung-Hee 한국정보처리학회 2002 정보처리학회논문지 A Vol.9 No.4

보관 중인 제품의 정확한 위치를 파악하는 것이 창고관리의 필수적인 요소이다. 그러나 제품이 빈번하게 위치를 변경하며 보관되는 경우에는 그 위치 파악이 어렵게 되며 이로 인해 효율적 창고관리가 불가능해진다. 본 논문에서는 임베디드 시스템과 무선 랜을 이용하여, 이러한 이동성이 높은 재고단위(SKU : Stock Keeping Unit)의 창고 내 위치관리에 응용할 수 있는 새로운 시스템을 제안한다. 시스템은 RFID(Radio Frequency IDentification)와 관리 단말기, 모바일 기기인 휴대폰과 PDA 그리고 중앙 관리 시스템으로 구성된다. 시스템의 사례로 이동성이 높은 재고단위의 모델인 대형 중고자동차의 위치관리시스템을 선택하였으며, 시스템이 운용되는 각 부서의 업무를 분석 후 기능별로 구현하였다. 본 연구를 통하여 무선 랜이 접목된 임베디드 시스템이 이동성 높은 재고단위의 입출고 상황과 창고 내에서의 위치를 실시간 적으로 정확하게 파악할 수 있어, 창고의 운영 및 관리를 체계적으로 처리할 수 있음을 보인다. It it essential to get the exact location information of products for a warehouse management. It is very hard, however, to know the location of products which change their location in warehouse frequently This causes the effective warehouse management to be almost impossible. In this paper, we suggest a new location management system for such a SKU(Stock Keeping Unit) with high mobility. The system is composed of RFID (Radio Frequency IDentification), a management terminal with wireless LAN, mobile devices (Cellular Phone & PDA), and a central management system. As a model of a SKU with high mobility, we selected a used-car stored in a large-scale warehouse. We designed and implanted used-car location management system. After analyzing the operations of each position in used-car warehouse where the system will run, we implemented each function. This research shows that an embedded system with wireless LAN is able to know the status of coming in and cut and location of a SKU with high mobility in warehouse very accurately in real time. Therefore, it makes the warehouse to be controlled systematically.

애드 혹 네트워크에서 링크밀도기반 클러스터 구축을 이용한 효율적인 플러딩

이재현,권경희,Lee, Jae-Hyun,Kwon, Kyung-Hee 한국정보처리학회 2007 정보처리학회논문지 C : 정보통신,정보보안 Vol.14 No.7

Although flooding has the disadvantages like a transmission of duplicated packets and a packet collision, it has been used frequently to find a path between a source and a sink node in a wireless ad hoc network. Clustering is one of the techniques that have been proposed to overcome those disadvantages. In this paper, we propose a new flooding mechanism in ad hoc networks using cluster formation based on the link density which means the number of neighbors within a node's radio reach. To reduce traffic overhead in the cluster is to make the number of non-flooding nodes as large as possible. Therefore, a node with the most links in a cluster will be elected as cluster header. This method will reduce the network traffic overhead with a reliable network performance. Simulation results using NS2 show that cluster formation based on the link density can reduce redundant flooding without loss of network performance. 플러딩 방식은 중복 패킷 전송 과 패킷 충돌 같은 근본적인 문제점을 가지고 있으면서도 무선 애드 혹 네트워크에서 임의의 싱크 노드에 대한 경로를 찾기 위해 자주 사용된다. 플러딩 방식이 가지고 있는 이러한 문제점을 개선하기 위한 방법들 중의 하나로 클러스터 플러딩 기법이 제안되어 사용되고 있다. 본 논문에서는 임의의 노드로부터 통신범위 안에 있는 노드들의 수인 노드들의 밀집도 이용하여 헤더를 선출하는 밀도기반 클러스터 플러딩 기법을 제안한다. 네트워크에서 발생하는 중복 패킷전송 및 패킷충돌과 같은 추가비용을 감소하는 방법은 플러딩을 하지 않는 비 플러딩(non-flooding) 노드를 가능한 한 많이 만드는 것이고, 이를 위해서는 가능한 많은 노드들을 멤버로 가지고 있는 클러스터 헤더를 선출하는 것이다. 제안한 방식은 신뢰할 수 있는 네트워크를 유지하고, 네트워크 트래픽의 효율성을 증가시킬 것이다. 본 논문에서는 NS2를 이용한 시뮬레이션을 통하여 기존의 클러스터 방식에 비해 밀도 기반 클러스터가 비 플러딩 노드의 수를 증가시켜 네트워크의 성능저하 없이 네트워크 트래픽의 효율성이 향상되는 것을 확인한다.