Flowers Called Nowhere 장우철

장우철 메이데이 2021 Paper Vol.260 No.-

Therapeutic potential of autologous mesenchymal stem cells derived from synovial fluid in patients with degenerative arthritis

장우철,박상인,전선영,이의진,함현주,배윤진,김란,박문수,정용안,임노아,유승식,이민영,김종민,황기철,윤지순,맹이소 한국통합생물학회 2013 Animal cells and systems Vol.17 No.5

The possibility to isolate synovial fluid-derived mesenchymal stem cells (SFMSCs) from patients with degenerative arthropathy has been an interest since synovial fluid (SF) from osteoarthritis (OA) patients offered a unique stem-cell resource for therapeutic applications. In this study, we successfully isolated, cytogenetically and molecularly characterized, and followed the differentiation potency of human mesenchymal stem cells (MSCs) from SF. The morphology of proliferating SFMSCs showed fibroblast-like morphology, and both the population doubling time (DT) and viability of MSCs from bone marrow, adipose, and SF did not differ. The immunophenotype of SFMSCs was confirmed by the positive expression of CD44, CD73, CD90, CD105, and CD106 by flow cytometry and immunocytochemistry, and the expression of the hematopoietic markers, CD34 and CD45, was not found. In all MSCs from three different origins, we measured the mRNA expression of developmentally important transcript factors such as KLF4, c-Myc, Sox2, and OCT4. SFMSCs from OA patients showed normal chromosomal number, structure, and telomerase activity. SFMSCs showed multipotent capacity, and was differentiated into neurocyte, adipocyte, osteocyte, and chondrocyte in vitro, as demonstrated by specific stains and expression of molecular markers. In addition, SFMSCs also have the capacity to secrete immunomodulating factors (IL-4, IL-10, IL-13, and transforming growth factor-b (TGF-b)) involved in the therapy of rheumatoid arthritis (RA). These results demonstrate that SFMSCs from OA-patients might provide therapeutic options for RA and OA.

K개의 집합에 연결이 있는 네트에 K(K-1)/2의 비용을 주는 경우의 네트워크의 다중 분할

장우철,김인기,김경식,Jang, Woo-Choul,Kim, In-Ki,Kim, Kyung-Sik 대한전자공학회 1994 전자공학회논문지-B Vol.b31 No.11

본 논문에서는 네트워크의 노드들을 여러 집합으로 분할할 때 서로 다른 k개의 집합 사이를 연결하는 네트에 대해 비용을 k(k-1)/2로 주는 경우, 즉 완전 그래프 형태의 비용을 주는 경우의 분할 알고리듬을 제시한다. 이 문제는 Sanchis의 다중 부날 문제$^{[5]}$중의 하나로서 분산처리 시스템의 자원 할당에 적용될 수 있다. 제시된 알고리듬은 Fiduccia, Mattheyses 알고리듬$^{[3]}$을 확장하여 일시에 다중 분할하는 기법을 사용하였으며 네트워크의 크기에 선형으로 비례하는 시간 복잡도와 공간 복잡도를 가진다. 제시된 알고리듬의 성능을 평가하기 위해 네트별로 노드들을 그룹화시키는 클러스터 성장 방식과 결과를 비교했다. 실험 결과 일시에 다중 분할하는 제시된 알고리듬이 우수한 결과를 내었다. In this paper, we propose an algorithm on partitioning a network into several subsets where the cost of a net which connects nodes in k subsets is given as k(k-1)/2 indicating the typical pattern of complete graphs. This problem is one of generalizations for multiple-way partitioning proposed by Sanchis. $^{[5]}$ Its solution can be applied to resource allocation problem in distributed systems. The proposed algorithm expanded the algorithm of Fiduccia and Mattheyses$^{[3]}$ to handle the multiple-way partitioning simultaneously. It has time and space complexity linear to the size of the network. To evaluate the performance of the proposed algorithm, we implemented also a traditional cluster growth method which groups connected nodes for nets, and compared experimental results with those of the proposed algorithm. The proposed algorithm shows some enhancement made.

Survival of hypoxic human mesenchymal stem cells is enhanced by a positive feedback loop involving miR-210 and hypoxia-inducible factor 1

장우철,이민영,황기철,이창연,박준희,박문서,맹이소,윤치순,정용안 대한수의학회 2013 Journal of Veterinary Science Vol.14 No.1

The use of mesenchymal stem cells (MSCs) has emerged as a potential new treatment for myocardial infarction. However, the poor viability of MSCs after transplantation critically limits the efficacy of this new strategy. The expression of microRNA-210 (miR-210) is induced by hypoxia and is important for cell survival under hypoxic conditions. Hypoxia increases the levels of hypoxia inducible factor-1 (HIF-1) protein and miR-210 in human MSCs (hMSCs). miR-210 positively regulates HIF-1α activity. Furthermore, miR-210 expression is also induced by hypoxia through the regulation of HIF-1α . To investigate the effect of miR-210 on hMSC survival under hypoxic conditions, survival rates along with signaling related to cell survival were evaluated in hMSCs over-expressing miR-210or ones that lacked HIF-1α expression. Elevated miR-210expression increased survival rates along with Akt and ERK activity in hMSCs with hypoxia. These data demonstrated that a positive feedback loop involving miR-210 and HIF-1αwas important for MSC survival under hypoxic conditions.

Enhanced Healing of Rat Calvarial Bone Defects with Hypoxic Conditioned Medium from Mesenchymal Stem Cells through Increased Endogenous Stem Cell Migration via Regulation of ICAM-1 TargetedmicroRNA- 221

장우철,이소명,김란,박상인,정유진,함온주,이지현,김지형,오세경,이민영,김종민,박문서,정용안,황기철,맹이소 한국분자세포생물학회 2015 Molecules and cells Vol.38 No.7

The use of conditioned medium from mesenchymal stem cells may be a feasible approach for regeneration of bone defects through secretion of various components of mesenchymal stem cells such as cytokines, chemokines, and growth factors. Mesenchymal stem cells secrete and accumulate multiple factors in conditioned medium under specific physiological conditions. In this study, we investigated whether the conditioned medium collected under hypoxic condition could effectively influence bone regeneration through enhanced migration and adhesion of endogenous mesenchymal stem cells. Cell migration and adhesion abilities were increased through overexpression of intercellular adhesion molecule-1 in hypoxic conditioned medium treated group. Intercellular adhesion molecule- 1 was upregulated by microRNA-221 in mesenchymalstem cells because microRNAs are key regulators of various biological functions via gene expression. To investigate the effects in vivo, evaluation of bone regeneration by computed tomography and histological assays revealed that osteogenesis was enhanced in the hypoxic conditioned medium group relative to the other groups. These results suggest that behavioral changes of endogenous mesenchymal stem cells through microRNA-221 targetedintercellular adhesion molecule-1 expression under hypoxic conditions may be a potential treatment for patients with bone defects.

버섯 형태를 갖는 광대역 ENG 영차 공진 안테나

장우철(Woo-Cheol Chang),이범선(Bomson Lee) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.9

본 논문에서는 microstrip line에서 광대역 특성을 갖는 ENG(Epsilon Negative) ZOR(Zeroth-Order Resonant) 안테나를 설계, 제작, 측정 및 비교, 분석하였다. 제안된 안테나는 mushroom 구조를 이용하여 설계하였고, 영차 공진 단일 셀의 공진 주파수는 12 ㎓이다. 안테나 크기는 7.65×1.31×2.37 ㎜(or 0.306×0.053×0.095 λ ? at 9.2 ㎓)이다. 설계 방법은 방사 손실을 고려한 전송 이론 모델링을 바탕으로 설계하였다. 정합을 위한 결합 커패시터를 사용해서 안테나 공진 주파수가 9.2 ㎓로 낮아졌으며, 이 주파수에서 측정된 대역폭은 1,831 ㎒(20.0 %)이며, 최대 이득은 7.1 ㏈i이다. This Letter presents a wideband ENG(Epsilon Negative) ZOR(Zeroth-Order Resonant) antenna designed on a microstrip line. It has a mushroom structure and its size is only 7.65×1.31×2.37 ㎜(or 0.306×0.053×0.095 λ ? at 12 ㎓) owing to zeroth-order resonance. The design procedures with closed form solutions are provided using transmission line theory considering radiation loss. The measured antenna bandwidth is about 20.0 % at 9.2 ㎓ and antenna gain is 7.1 ㏈i despite the compact size.

서비스 경험이 관계지향성에 미치는 영향에 관한 연구 : 가맹점주의 인게이지먼트 조절효과를 중심으로

장우철(Woo-Choul Chang),전성준(Chengjun Quan),박성남(Seong-Nam Park),강기두(Gi-Du Kang) 대한경영학회 2021 大韓經營學會誌 Vol.34 No.12

현재 대한민국의 프랜차이즈 산업은 선진화되고 체계적인 경영시스템 부족으로 인하여 질적인 발전이 정체되어 있다. 또한 국내에서는 프랜차이즈의 급속한 성장에 따라 사회적 발전과 함께 폐해도 다수 발생하고 있다. 하지만 외형적인 성장에 따른 프랜차이즈 산업에서 그에 따른 생산적이고 창의적인 다양한 시각에서의 프랜차이즈 학술연구가 활발하지 않는 것 또한 엄연한 현실이다. 본 연구는 그동안 논의되지 않았던 가맹점주의 서비스 경험에 따른 장기 관계지향성(재계약의도와 재무적 성과, 평당 매출액<실제 매출데이터>), 가맹점주의 인게이지먼트, 관계품질의 다양한 변수들이 상호 간의 미치는 영향을 확인하고자 하였다. 본 연구는 2가지 업종(커피, 치킨)을 대상으로 프랜차이즈 업종에 종사하는 264명의 가맹점주를 대상으로 서비스 경험이 장기 관계지향성에 미치는 영향에 대해서 검증하였다. 연구결과, 서비스 경험은 재계약의도와 재무적 성과에는 유의한 정(+)의 영향을 미치는 것으로 나타났으나 평당 매출액에는 유의한 영향을 미치지 않는 것으로 나타났다. 관계품질의 매개효과 분석결과, 관계품질은 서비스 경험과 재계약의도, 서비스 경험과 재무적 성과 사이에서만 매개효과가 있음을 확인하였다. 마지막으로 인게이지먼트의 조절효과 분석한 결과, 서비스경험이 재계약의도와 서비스 경험이 재무적 성과에 미치는 영향에 대해 조절효과가 있는 것으로 확인되었다. 기존 가맹본부와 가맹점의 관계를 논의한 다수의 연구들은 가맹본부의 입장에서 가맹점에 대한 가맹본부의 지원서비스에 대한 논문이 대다수를 차지하였다. 본 연구는 가맹본부와 가맹점주를 대등한 입장에서 설정하고 연구를 진행하였다는 점에서 차별점을 지니고 있으며 이에 따라 학술적이고 이론적인 시사점을 갖고 있다. The quality of the franchise industry in Korea is stagnant due to the lack of an advanced and systematic management system. However, in Korea, along with the rapid growth of franchises, a number of negative effects are occurring along with social development. However, it is also the reality that academic research on franchises from various productive and creative perspectives is not active in the franchise industry according to the external growth. This study tried to verify the effect of mutual variables of long-term relationship intention(Intention to renew the contract and financial performance, actual sales data) according to franchisees service experience, which were not previously discussed, and the variables of franchisees engagement and relationship quality. This study investigated the effect of service experience on long-term relationship intention for 264 franchisees in two kind of industries(coffee-shop and chicken). As a result of the study, it was found that service experience had a positive, significant effect on contract renewal intention and financial performance, but had no significant effect on sales per area. On the other hand, as a result of examining the mediating effect of relationship quality, it was confirmed that relationship quality had a mediating effect between service experience and contract renewal intention, service experience and financial performance. Also, as the result of confirming the moderating effect of engagement, it was verified that service experience had a moderating effect on the contract renewal intention and the effect of service experience on financial performance. This study is different in that the franchise headquarters and franchise owners were set and conducted on the same level and accordingly, it has academic and theoretical implications.

완전 그래프 형태로의 일시 다중 분할 ( A Simultaneous Multiple-Way Partitioning of a Network into Complete Graph Style Sub-Blocks )

김인기,장우철,김경식 대한전자공학회 1993 대한전자공학회 학술대회 Vol.1993 No.1

온라인 조사에 의한 컨셉 테스트 타당성 검증: 오프라인 조사와 비교

현인경,장우철,김근배,이상진 대한경영학회 2023 大韓經營學會誌 Vol.36 No.1

The main purpose of this research is to empirically verify the validity of the online concept test by directly comparing the online and off-line surveys in the concept test, a type of consumer survey when developing new products. The effect of the presentation of illustration on purchase intention and understanding in the concept test, a type of consumer survey before launch, was investigated by survey types(online Vs. off-line) when developing a new product. For this research, the experiment was designed with the 2x2 between-subjects factorial design. The independent variable was the presentation of the illustration, the moderator variable was the survey type. There are two dependent variables. The one is purchase intention and the other is the degree of understanding. As a result of the research, it was confirmed that there was no difference in the presentation of product and service illustration in both the online and off-line surveys in terms of purchase intention. In the concept test, it was confirmed again that the illustration, that is, whether an illustration was presented or not, did not show the significant difference in the purchase intention of consumers. This means that feasibility can be secured even if the off-line concept test is directly applied online test. It also means that you don't necessarily have to present an illustration when doing an online survey. This was confirmed again that during the concept test, the presentation of the illustration did not affect the purchase intention of consumers. In particular, in the case of the service concept test, the presentation of illustration was analyzed to be highly evaluated in terms of differentiation, which means that when designing the differentiated service concept, the question of differentiation must be included in the concept test. Additionally, it was confirmed that there was no difference in the presentation of illustration in terms of purchase intentions in both product and service, online and off-line surveys. The results of the research degree of understanding, it was confirmed that there was a statistically significant difference between product and service in the results of whether or not illustration was presented. Also, in the case of testing the service concept, the presentation of illustration was highly evaluated in the differentiation category. This means that, unlike the existing marketing literature research, when designing the differentiated service concept, the question of differentiation should not necessarily be excluded from the concept test. Through this study, it is expected that it will provide practical help to the managers of research companies and marketers, and help researchers diversify their academic interests in the existing traditional survey.

CSR 지향성의 척도개발에 관한 연구

이근태,장우철,서진희,강기두 한국기업경영학회 2016 기업경영연구 Vol.23 No.5

The radical changes in the managerial environment have requested modern organizations to treat the CSR as embedded organizational culture in their implementations of CSR. They have also indicated that doing so would be effective and efficient ways to address the whole issues of CSR. To this regard, the current study attempted to integrate the concepts of CSR and company's orientation to provide the new research construct(i.e., CSR Orientation). The current study reasoned that there are several overall aspect in CSR and company's orientation; therefore, it seems to be much more reasonable to have a succinct and parsimony construct per se. In order to identify the construct of CSR orientation, it was necessary to cleary understand the meanings of CSR and organizational culture. To this respect, extensive reviews of extant literature were implemented and specifically, several academic databases(e.g., EBSCO, RISS, KISS etc) were examined and reviewed. In so doing, tentative definition and structures of CSR orientation were proposed; but it has to be subject to be justified. Field interviews, therefore were employed to reflect the ideas and thoughts on CSR orientation from the perspectives of practitioners. In a practice of expert interview, especially, the content validity for CSR orientation was assessed. Above mentioned procedures make possible to identity and suggest the definition and measures of CSR orientation. While the measures of CSR orientation were developed by above mentioned procedure, the current study fully adapt the process for developing the scale proposed by Churchill(1979). Having a concrete definition and identifying the sub-constructs, in fact, fully followed the Churchill's proposition. In relation to the scale development, 10 sub-constructs and 126 measures of CSR orientation were initially developed; and examples of the constructs(and the numbers of developed measures) were rational(12), economic(10), employee(12), customers(14), social(15), environmental(12), orientation(12), structure(10), system(12) and competency(17). A total of 356 data collected from the employees at the big-sized companies located in Seoul were analyzed by SPSS and LISREL to implement such analyses as correlational analysis, reliability test, exploratory factor analysis, and confirmatory factor analysis. In order to purify and validate the data set, the data collected were randomly divided into two; one is for the data purification and another is for the data verification. The analyses for the 1st data set(n=184) showed that 44 items with 10 sub-construct were retained after several reiterative purification processes. Such psychometric properties as composite reliability, convergent validity, and discriminant validity were also assessed and the results showed that all appear to be reliable and valid. In order to confirm the proposed structure, the 2nd data set(n=172) was also empirically examined. In addition to assess the similar psychometric properties, nomological validity was examined by using this data set. Specifically the relationship between perceived performance and CSR orientation were examined. The results for the nomological validity testing showed that CSR orientation is significantly related with perceived performance so that a certain nomological network is formed. By conceptualizing and developing the measure for CSR orientation, the current study could shed some lights on several implications. Firstly, as indicated earlier, the current study provided the good foundation to consider the CSR as a key organizational culture. Secondly, it give some guidelines to the organizations as to which types of works should be done for being more socially responsible. As the other studies, the current study also appears to have research limitations and further studies are expected to address them. The current study assessed the CSR orientation only from the organizational perspective so that it would be necessary to asse... 21세기 급격한 경영환경의 변화에 직면하고 있는 기업들에 있어서 CSR 수행은 이제 조직 내에 배태된(embedded) 문화로 접근하여야 할 필요성이 있다는 점이 제기되고 있다. 이에 본 연구는 CSR(Corporate Social Responsibility)을 조직 문화적 관점에서 접근하기 위하여 해당 두 개념을 연결, 통합하는 새로운 개념인 ‘CSR 지향성‘을 연구개념을 제안하고 그 측정 척도개발을 시도하였다. 이를 위하여 선행연구들에서 해당 두 개념과구성차원들을 확인하였고, 기업경영 현장으로부터 조직문화로서 CSR 즉, ‘CSR 지향성’의 정의를 파악함과 동시에 그 구성차원 또한 확인하여 내용타당성을 확보하였다. 그리고 그에 대한 비교, 검토를 통해 새로운 ‘CSR 지향성’의 개념적 정의를 도출하는 것과 함께 그를 구성하는 10개의 구성차원이 파악되었다. 이어서 그 10개의구성차원을 설명할 수 있는 115개의 문항이 개발되어 데이터 수집이 이루어졌고 반복된 척도 정제 절차를 거쳐 ‘CSR 지향성’을 적절히 측정할 수 있는 44개의 척도가 최종적으로 개발되었으며, 이는 계량심리학적 속성분석을 통해 타당성과 신뢰성을 지닌 척도임이 입증되었다. 본 연구의 이 같은 개념의 제시와 척도개발은, 향후 보다 성공적인 CSR 수행을 위한 연구의 기초가 될 것이며 기업들에 있어서 효과성 있는 CSR 실천의 지침이 될 수 있으리라 기대한다.