Quantum Phase Transitions in an ionic Hubbard Model in One Dimension

이지우,Ji-Woo Lee 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.4

We study quantum phase transitions in an ionic Hubbard model in one dimension. This model accounts for the electrons in the alternating potentials with a lattice period of 2. For a specified alternating potential of strength Δ, we change the local repulsion between spin-up and spin-down electrons U for the model to exhibit a quantum phase transition from a band insulator to Mott insulator. Via exact diagonalization with a modified Lanczos method, we find that the ground-state energy shows a level crossing at half-filling as we tune U. We obtain a phase diagram of the model by finite-size scaling method. Also we find an interesting feature of double occupancy around the phase transitions.

자연기반해법 적용에 따른 강원도 양구군 해안면의 비점오염 저감 효과 추정

이지우,박찬,Lee, Ji-Woo,Park, Chan 한국환경복원기술학회 2022 한국환경복원기술학회지 Vol.25 No.3

The Ministry of Environment has been working to reduce the impact on biodiversity, ecosystems, and social costs caused by soil runoff from highland Agricultural fields by setting up non-point pollution source management districts. To reduce soil loss, runoff path reduction technology has been applied, but it has been less cost effective. In addition, non-point pollution sources cause environmental conflicts in downstream areas, and recently highland Agricultural fields are becoming vulnerable to climate change. The Ministry of Environment is promoting the optimal management plan in earnest to convert arable land into forests and grasslands, but since non-point pollution is not a simple environmental problem, it is necessary to approach it from the aspect of NbS(Nature-Based Solution). In this study, a scenario for applying the nature-based solution was established for three subwatersheds west of Haean-myeon, Yanggu-gun, Gangwon-do. The soil loss distribution was spatialized through GeoWEPP and the amount of soil loss was compared for the non-point pollution reduction effect of mixed forests and grasslands. When cultivated land with a slope of 20% or more and ginseng fields were restored to perennial grasslands and mixed forests, non-point pollution reduction effects of about 32% and 29.000 tons compared to the current land use were shown. Also, it was confirmed that mixed forest rather than perennial grassland is an effective nature-based solution to reduce non-point pollution.

조직혁신에 관한 연구모형의 개발과 연구명제의 설정

최만기(Man Kee Choe),이지우(Ji Woo Lee) 한국경영학회 1998 經營學硏究 Vol.27 No.5

As the 21st, century approaches, globalization and change to are information and knowledge society have accelerated hypercompetitive environments. Under such environments, to survive and grow organizations should maintain continuous innovation. Although organizational innovation has attracted many scholars and managers for long time, the research of organizational innovation has not been accumulated because of nonexistence of a comprehensive and systematic model on organizational innovation. This study, therefore, has provided underlying logics of designing Choe and Lee`s integrated model of organizational innovation based on comprehensive review of existing studies. This study has also generated important propositions underlying the model focusing on organizational innovation per se. This study. further, has exemplified hypotheses derived from each proposition for future studies.

Workflow Technology and Employee Responses : A Comparison Across Dimensions and Levels

Lee Ji Woo(이지우) 啓明大學校 産業經營硏究所 2011 會計情報리뷰 Vol.- No.17

기술의 다양한, 측면들이 종업원들의 과업특성지각과 직무관련 태도에 미치는 영향을 살펴보았다. 기술의 변화성과 분석가능성이 불확실성, 복잡성, 그리고 상호의존성에 비해 더 큰 영향을 미치는 것으로 밝혀졌다. 그리고 단위부서 수준의 기술과 개인 수준의 기술이 동시에 영향을 주는 것으로 나타났다. 이런 효과는 거시적(global)지표나 부서 구성원들 평가를 합친(aggregated) 지표 중 어느 것을 사용하는지 상관없이 나타났다. 그리고 개인 수준이 기술에 대한 평가를 합친 것보다 단위부서 수준의 기술에 대한 평가를 합쳐 부서수준 기술 지표로 사용했을 때 보다 충실한 예측이 가능한 것을 밝혀졌다.

주류 및 음료에서의 퍼클로레이트 모니터링

이지우(Ji-Woo Lee),오성희(Sung-Hee Oh),Mandy Pawlas,오정은(Jeong-Eun Oh) 한국환경독성학회 2010 한국독성학회 심포지움 및 학술발표회 Vol.2010 No.11

직무열의(Job engagement)의 연구 동향과 과제

이지우(Lee, Ji Woo) 계명대학교 산학연구소 2010 經營經濟 Vol.43 No.1

The value of engagement would seem to lie in its foundation in positive psychology. Too often management and organizational psychologist focused on problems and deficits with organizational members. Work engagement has emerged as a potentially important employee performance and organizational behavior topic. A growing body of evidence supports the relationship between engagement of employee at work and organizational outcomes, including job performance and organizational effectiveness. In order to build upon a potentially significant area in employee performance research, a review of the literature examining the current state of knowledge about engagement at work IS conducted. Forty rune studies are identified and their findings are analyzed. This review focuses on three lines of engagement research and highlights the nature of the construct, determinants, and consequences of work engagement. Work engagement gives practitioners and organizational leaders the opportunity to focus on positive aspects of the workplace and to concentrate on developing interventions that foster organizational members’ happiness and well-being. The issues and recommendation for future research are also provided.

지난 10년 간 인사·조직 연구의 발전과 앞으로의 과제

이지우(Lee, Ji-Woo) 계명대학교 산학연구소 2010 계명대학교 산업경영연구소 단행본 Vol.- No.-

This study is performed to evaluate the achievement of the research on Organizational Behavior and Human Resource Management during the first 10 years of the 2000s. From 2000 to 2009, 366 OB/HRM articles were published in three major academic journal of those fields, Korean Journal of Management, Journal of Human resource Management, Korean Management Review. Based upon the main purpose and contents of the articles, 221 are divided into OB and 145 into HRM area. The OB papers are classified into 58 categories, whereas the HRM articles are divided into 40 categories by their man research focus. Among OB area, Organizational Citizenship Behavior, emotional labor, and stress are found as the research topics studied most for the last 10 years. Human resource management practice and system and temporary working are most widely studies area in the field of HRM for the same period. The current state of knowledge about OB/HRM are discussed and issues and recommendation for future research are provided.

작업집단내 동료간 과업수행관계의 영향요인들

이지우 ( Ji Woo Lee ) 한국인적자원관리학회 2009 인적자원관리연구 Vol.16 No.2

조현병 환자, 치매 노인과 일반 노인의 얼굴자극평가(FSA) 반응특성

이지우(Lee Ji-woo),김갑숙(Kim Gab-sook) 한국미술치료학회 2020 美術治療硏究 Vol.27 No.3

본 연구는 조현병 환자, 치매 노인과 일반 노인의 FSA(Face Stimulus Assessment) 반응특성의 차이를 살펴보고 FSA가 조현병 환자, 치매 노인과 일반 노인을 타당하게 구별할 수 있는지를 알아보고자 하였다. 이를 위하여 2017년 5월부터 2017년 10월까지 조현병과 치매를 진단받고 입원한 환자 각각 50명과 일반 노인 50명으로 총 150명을 대상으로 FSA 검사를 실시하였다. 자료 분석은 각 집단에 따른 FSA 반응의 차이를 알아보기 위한 교차분석과 FSA 변인들의 변별력을 알아보기 위한 판별분석을 실시하였다. 연구의 결과는 다음과 같다. 집단에 따라 FSA 그림 1, 2에서 12개의 모든 변인인 ‘색칠 정도’, ‘색의 적절성’, ‘에너지’, ‘논리성’, ‘사실성’, ‘발달단계’, ‘세부사항’, ‘선의 질’, ‘보속성’, ‘그림의 형태’, ‘그림의 정서적 내용’, ‘사용한 색의 수’에서 유의미한 차이가 나타났다. FSA 그림 1에서 이 변인들이 집단을 예측할 수 있는 전체 판별력은 88.6%이며, 조현병 환자는 90.0%, 치매 노인은 84.0%, 일반 노인은 90.0%였다. FSA 그림 2에서 이 변인들이 집단을 예측할 수 있는 전체 판별력은 85.3%이며, 조현병 환자는 72%, 치매 노인과 일반 노인은 92%였다. 이상에서와 같이 FSA는 집단별 특징을 잘 나타내고 있어 치매나 조현병 진단 시 신경심리검사에서 확인하기 어려운 비언어적 정서를 파악하는데 활용될 수 있음을 확인하였다. The aim of this study was to investigate the differences in the characteristics of the responses to Face Stimulus Assessment(FSA) drawings among patients with schizophrenia, older people with dementia, and normal older people. For this purpose, the FSA test was conducted with a total of 150 participants from May to October 2017. The participants consisted of 50 schizophrenia patients and 50 dementia patients in a Psychiatric Hospital and 50 normal older people from Senior Welfare Center. To analyze the data, cross-tabulation analysis and discriminant analysis were carried out. The results of this study were as follows: With respect to FSA Drawings 1 and 2, there were statistically significant differences among the three groups in all 12 variables: “prominence of color,” “color fit,” “implied energy,” “logic,” “realism,” “developmental level,” “details of objects & environment,” “line quality,” “perseveration,” “drawing type,” “emotional content,” and “number of used colors.” In the case of FSA Drawing 1, the overall discriminant power of these variables to discriminate groups was 88.6%, with 90.0% for schizophrenia patients, 84.0% for dementia patients, and 90.0% for normal older people, respectively. In the case of FSA Drawing 2, the overall discriminant power of these variables to discriminate groups was 85.3%, with 72% for schizophrenia patients and 92.0% for dementia patients and normal older people, respectively. Each group was well characterized by the FSA.

RELATIONSHIP BETWEEN LEADER-MEMBER EXCHANCE AND CAREER OUTCOMES

Ji-Woo Lee(李枝雨) 계명대학교 산학연구소 1991 經營經濟 Vol.24 No.1