• 한국인터넷방송통신학회논문지
• /
• 제14권5호
• /
• pp.263-269
• /
• 2014

본 논문은 지금까지 미해결 문제로 알려진 정점 색칠 문제에 대한 Hadwiger 추측의 반증을 제시하였다. Hadwiger 추측은 "모든 $K_k$-minor free 그래프는 k-1개의 색으로 칠할 수 있다. 즉, $K_k$-마이너를 얻으면 ${\chi}(G)=k$이다." Hadwiger 추측을 적용하여 정점 색칠을 할 경우, 먼저 NP-완전 (NP-complete)인 $K_k$-마이너를 구하여 ${\chi}(G)=k$를 결정하고, 다시 NP-완전인 정점 색칠 문제를 풀어야 한다. Hadwiger 추측을 반증하기 위해 본 논문은 정점 색칠의 정확한 해를 O(V)의 선형시간으로 구하는 알고리즘을 제시하였다. 제안된 알고리즘은 그래프의 최소 차수를 가진 정점을 최대독립집합 (MIS)으로 하고, MIS 정점의 인접 정점 간선을 삭제한 축소된 그래프에 대해 이 과정을 반복하면서 하나의 색을 가진 MIS를 얻는다. 다음으로 MIS 정점의 간선을 삭제한 축소된 그래프에 대해 동일한 과정을 수행하여 MIS의 개수가 정점 채색수 ${\chi}(G)=k$가 되는 해를 얻는다. 제안된 알고리즘을 적용하여 NP-완전 문제인 완전 색칠 (total coloring) 채색수 ${\chi}^{{\prime}{\prime}}(G)$의 해를 구하는 알고리즘을 제안하였다. 제안된 알고리즘을 $K_4$-마이너 그래프에 적용한 결과 ${\chi}(G)=4$가 아닌 ${\chi}(G)=3$을 얻었다. 결국, Hadwiger 추측은 모든 그래프에 대해 적용되지 않음을 알 수 있다. 제안된 알고리즘은 마이너를 구하지 않으며, 주어진 그래프에 대해 직접 ${\chi}(G)=k$인 독립집합 마이너를 구하여 각 독립집합 정점들에 동일한 색을 배정하는 단순한 방법이다.

• 근관절건강학회지
• /
• 제15권1호
• /
• pp.5-23
• /
• 2008

Purpose: This study aims to conduct a systematic review of the physical, psychosocial and physiological effects of Tai Chi exercise in elderly. Method: 37 articles from Medline search of foreign journals (1966-2006) were surveyed by the key words 'Tai Chi', 'Tai-chi program' and 'Tai-chi and elderly' limiting the range to age 65 or older, choosing clinical trial and randomized controlled trial research in English articles. Four articles were excluded due to methodological study, pilot study and review. The research was analyzed according to health status of the subjects, styles and forms of Tai Chi exercises, factors for physical, psychosocial and physiological measures. Result: A short forming Yang style was commonly used in chronic diseases and health for elderly. Variable outcome measures were used in Tai Chi studies relating to balance, muscle strength, walking and mobility, flexibility and cardiorespiratory function in physical measure, quality of life, depression, self-efficacy, health status, cognition and impact questionnaire in psychosocial measure, lipids, insulin resistance and hormone in physiological measure. Conclusion: Tai Chi exercise appears to have physical and psychosocial benefits and also appears to be safe for elderly and chronic diseases. It is suggested that future studies analyze statistical part of systematic reviews through meta analysis.

• 대한수학회보
• /
• 제51권6호
• /
• pp.1615-1623
• /
• 2014

Let $G{\leq}S_n$ and ${\chi}$ be any nonzero complex valued function on G. We first study the irreducibility of the generalized matrix polynomial $d^G_{\chi}(X)$, where $X=(x_{ij})$ is an n-by-n matrix whose entries are $n^2$ commuting independent indeterminates over $\mathbb{C}$. In particular, we show that if $\mathcal{X}$ is an irreducible character of G, then $d^G_{\chi}(X)$ is an irreducible polynomial, where either $G=S_n$ or $G=A_n$ and $n{\neq}2$. We then give a necessary and sufficient condition for the equality of two generalized matrix functions on the set of the so-called ${\chi}$-singular (${\chi}$-nonsingular) matrices.

• 호남수학학술지
• /
• 제28권2호
• /
• pp.197-204
• /
• 2006

For the evaluation algebra $F[e^{{\pm}{\chi}}]_M$, if M={$\partial$}, the automorphism group $Aut_{non}$($F[e^{{\pm}{\chi}}]_M$) and $Der_{non}$($F[e^{{\pm}{\chi}}]_M$) of the evaluation algebra $F[e^{{\pm}{\chi}}]_M$ are found in the paper [12]. For M={${\partial}^n$}, we find $Aut_{non}$($F[e^{{\pm}{\chi}}]_M$) and $Der_{non}$($F[e^{{\pm}{\chi}}]_M$) of the evaluation algebra $F[e^{{\pm}{\chi}}]_M$ in this paper. We show that a derivation of some non-associative algebra is not inner.

• Journal of applied mathematics & informatics
• /
• 제6권3호
• /
• pp.859-866
• /
• 1999

In Eucliden k-space the cone of vectors x=($\chi$1, $\chi$2, ...,$\chi$k) satisfying $\chi$1$\leq$$\chi$ 2, $\leq$...$\leq$$\chi$k and {{{{ SUM { }`_{j } ^{k } }}= 1 $\chi$j=0 is generated by the vectors vj=(j-k,...j-k...j) having j-k's in its first j coordinates and j's for the remaining k-j coordinates for 1$\leq$j$\leq$i

• 한방비만학회지
• /
• 제6권2호
• /
• pp.43-49
• /
• 2006

Objective : This study was conducted to offer basic materials for the clinical study of Chi acupuncture (carboxytherapy). Methods : Recent clinical studies were reviewed for carboxytherapy (carbon dioxide therapy) and the ancient and present texts were reviewed for Chi acupuncture. Results and Conclusions : Chi acupuncture is oriental medical therapeutic treatment using carboxytherapy. Chi acupuncture refers to the transcutaneous administration of CO2 gas for therapeutical purposes relating to obesity, cellulites, local circulation and skin irregularity. Recent studies have demonstrated the effects of this therapy on adipose tissue by showing vasomotor effects, increasing local circulation and inducing a partial increase in tcPO2. Chi acupuncture influences the microcirculation and likely has a positive effect upon the physiological oxidative lipolytic process.

• Journal of Photoscience
• /
• 제9권2호
• /
• pp.74-77
• /
• 2002

Chlorophyll (Chi) d was assigned to an antenna pigment of red algae in 1943, but its presence and function in red algae have not been necessarily clear for a long time. In 1996, it was shown that Chi d functioned as a major antenna pigment in a peculiar oxygenic photosynthetic prokaryote, Acaryochloris marina, isolated as a symbiont of a colonial ascidian from coral reefs. This finding evoked the necessity for reexamination of the presence and function of Chi d in red algae. We found Chi d in methanol-extract from several marine red algae, and the relative content was high in one species, Ahnfeltiopsis flabelliformis. Absorption and fluorescence spectra, HPLC analysis, and NMR and mass spectroscopy characterized Chi d extracted from the red algal thalli, and those were essentially identical to those of Chi d isolated from A. marina. However, micro-spectrophotometric analysis suggested that Chi d was not an actual constituent of the red algae but came from epiphyte(s) attached to surface of red algal thalli.

• 정보관리연구
• /
• 제43권4호
• /
• pp.1-29
• /
• 2012

헬스리터러시(Health Literacy)는 적절한 건강진단을 위한 기본적인 건강정보 및 서비스를 획득하고 처리하고 이해할 수 있는 능력으로서, 사서들은 이용자뿐만 아니라 자신들의 헬스리터러시도 향상시켜야 한다. 이에 본 연구에서는 국내 공공도서관 사서에게 적합한 건강정보활용교육 프로그램 개발에 기여하고자 건강관련 교육프로그램을 개발하고 이를 사서교육에 적용하였으며, 그 효과를 측정하고 개선사항도 발견하였다. 그 결과, 공공도서관 사서의 CHI(Consumer Health Information) 관련 용어에 대한 친숙도 증가, 교육후 이용자에 대한 교육증가 및 내용의 다양화, CHI관련 서비스를 수행하기 위해 활용하는 정보원의 다양화 및 전문화, 참고서비스에 걸리는 시간 절감 및 전문지식 부족의 한계에 대한 부담 감소 등의 부분에서 효과가 있었던 것으로 나타났다. 그러나 본 연구는 사서대상 CHI관련 교육과 관련하여 국내에서 최초로 수행된 연구로 교육강사 및 주제의 다양성, 방법론 부분에서 많은 한계가 있었으며, 향후 보다 발전된 CHI관련 교육 프로그램의 개발이 요구된다고 할 수 있다.

• 성인간호학회지
• /
• 제23권3호
• /
• pp.288-297
• /
• 2011

Purpose: The purpose of this study was to explore the experiences of Tai Chi in women with osteoarthritis. Methods: Data were collected by face-to-face interview from 14 participants. Theoretical sampling was performed until the concepts were saturated. The main question was "How do you describe your experience of Tai Chi?" Data were analyzed using a grounded theory methodology. All interviews were audio taped and transcribed verbatim. Results: The Phenomenon is 'QI flowing'. The core category was identified with 'inspiring one's life with strength'. This series of processes was categorized into four stages: 'Challenging Tai chi', 'Doing one's best', 'Deplenishing (the word used in English and Tai chi is emptying one's mind) one's mind', 'Taking a Positive view of life'. Conclusion: The finding of this study will offer profound understanding about the reported tai chi's experience. Additional research should be done as to the role of Tai chi as a nursing intervention strategy for osteoarthritis patients.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권8호
• /
• pp.269-280
• /
• 2020

The study investigates Environmental Accounting Information (EAI) as well as factors affecting the environmental accounting implementation by the construction firms listed on the Ho Chi Minh Stock Exchange (HOSE), Vietnam. After eliminating seven enterprises that lacked data, the authors selected a sample of 112 observations from 28 construction businesses listed on the Ho Chi Minh Stock Exchange in the period 2015-2018. This study uses research data extracted from the companies' annual reports. Then, the data are analyzed by Stata 13 software, including descriptive statistics, correlation coefficient analysis, regression analysis of table data using estimation methods (Pooled OLS, REM, FEM), and testing of model defects (heteroskedasticity test, multicollinearity test, autocorrelation test). The results show that construction companies listed on the Ho Chi Minh Stock Exchange have out factors affecting the environmental accounting implementation by these enterprises, including independent audit firm and listed time. While the independent auditor firm has a positive and significant impact, the listed time has a negative influence. In addition, our study has confirmed the role of institutional factors affecting the disclosure level of EAI on the implementation of environmental accounting by construction enterprises listed on the Ho Chi Minh Stock Exchange.