• 에너지공학
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• 제16권1호
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• pp.32-39
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• 2007

석탄 열분해 공정은 석탄의 종류와 산지에 따른 변화가 커서 반응특성을 석탄의 모든 종류에 일반화시키기는 어려우며, 열분해, 가스화 및 연소현상이 동시에 발생하므로 석탄의 종류에 따라 운전조건을 변화시켜 실험장치로부터 최적의 반응 조건을 찾는 것이 중요하다. 본 연구에서는 키데코탄을 대상으로 압력 $2kg_{f}/cm^{2}$ 온도 $735{\sim}831^{\circ}C$의 가압유동층 반응기에서 가스화 반응을 수행하였으며 스팀공급량, 석탄공급량, 공기공급량 등 실험 변수에 따른 가스화 반응의 변화를 관찰하였다. 또한 여러 실험변수들의 변화에 따른 생성가스 성분의 변화를 정량적으로 분석하고, 생성가스 중 $H_{2}$와 CO의 농도를 기준으로 최적의 반응 조건을 결정하였다. 본 실험에서의 최적의 반응 조건은 공기/석탄 비 4.45, 스팀/석탄 비 0.21이었다. 가스화 반응보다 연소반응이 활발하게 일어나면 반응온도가 급격히 증가하므로 안정적인 가스화를 위하여 석탄과 스팀의 주입속도 조절이 매우 중요하였다. 연속운전을 위한 안정적인 운전조건에서 생산되는 발생가스의 CO의 농도는 약 18%, $H_{2}$의 농도는 약 17%였다.

• International Journal of Oral Biology
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• 제40권1호
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• pp.19-25
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• 2015

Osteocytes may function as mechanotransducers by regulating local osteoclastogenesis. Reduced availability of oxygen, i.e. hypoxia, could occur during disuse, bone development, and fracture. Receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) is an osteoblast/stromal cell derived essential factor for osteoclastogenesis. The hypoxia induced osteoclastogenesis via increased RANKL expression in osteoblasts was demonstrated. Hypoxic regulation of gene expression generally involves activation of the hypoxia-inducible factor (HIF) transcription pathway. In the present study, we investigated whether hypoxia regulates RANKL expression in murine osteocytes and HIF-$1{\alpha}$ mediates hypoxia-induced RANKL expression by transactivating RANKL promoter, to elucidate the role of osteocyte in osteoclastogenesis in the context of hypoxic condition. The expression levels of RANKL mRNA and protein, as well as hypoxia inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) protein, were significantly increased in hypoxic condition in MLO-Y4s. Constitutively active HIF-$1{\alpha}$ alone significantly increased the levels of RANKL expression in MLO-Y4s under normoxic conditions, whereas dominant negative HIF-$1{\alpha}$ blocked hypoxia-induced RANKL expression. To further explore to find if HIF-$1{\alpha}$ directly regulates RANKL transcription, a luciferase reporter assay was conducted. Hypoxia significantly increased RANKL promoter activity, whereas mutations of putative HIF-$1{\alpha}$ binding elements in RANKL promoter prevented this hypoxia-induced RANKL promoter activity in MLO-Y4s. These results suggest that HIF-$1{\alpha}$ mediates hypoxia-induced up-regulation of RANKL expression, and that in osteocytes of mechanically unloaded bone, hypoxia enhances osteoclastogenesis, at least in part, via an increased RANKL expression in osteocytes.

• 한국항해학회지
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• 제19권2호
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• pp.23-75
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• 1995

A major change occuring in the workplace is the willingness of union leaders, managers, and workers to experiment with various work schedules and to work toward the improvement in the QWL(quality of work life). In this study, the writer measures the level of QWL, embodies components of QWL, testifies the difference of QWL according to the demographical traits, and develops some scales to measure QWL in merchant ships. To achieve objectives of the paper, 11 hypotheses were established and a questionnaire was used, 894 proper data was obtained from 2, 910 Korean seamen working in merchant ships. Results of analyses are as follows : 1) The components of QWL in merchant ships are job, employee satisfaction, wage, welfare, working condition, supervise, colleague relations, initiative, and organization management. 2) Seamen of merchant ships are satisfied with job, supervise, colleague relations, and organization management. They are dissatisfied employee satisfaction, wage, welfare, and working condition. 3) According to demographical traits, the number of the factors significant difference(P<0.05) among components of QWL are 9 for type of ships, 8 ages of seamen, 7 for married or single, nationality of ships, and education level respectively, 5 for seamen career, for 4 rank on board and trading route of ships respectively, 2 for whether union or not and whether union involvement or not respectively, and 1 for department on board. 4) Results which tested hypotheses are as follows : For the components of QWL, married men are more satisfactory than an unmarried men, officers are more dissatisfactory than ratings, old men are more satisfactory than young men, men in high education level are more dissatisfactory than men in low education level, those who are much careers as a seaman are more satisfactory than those who are little careers as a seaman. There are significant differences in the components of QWL according to nationality and type of ships. There are insignificant differences in the components of QWL according to the shipboard department, whether union is or not, whether union involvement is or not, and trading route of ships.

• East Asian mathematical journal
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• 제25권2호
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• pp.179-196
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• 2009

Let E be a uniformly convex Banach space and K a nonempty closed convex subset which is also a nonexpansive retract of E. For i = 1, 2, 3, let $T_i:K{\rightarrow}E$ be an asymptotically nonexpansive mappings with sequence ${\{k_n^{(i)}\}\subset[1,{\infty})$ such that $\sum_{n-1}^{\infty}(k_n^{(i)}-1)$ < ${\infty},\;k_{n}^{(i)}{\rightarrow}1$, as $n{\rightarrow}\infty$ and F(T)=$\bigcap_{i=3}^3F(T_i){\neq}{\phi}$ (the set of all common xed points of $T_i$, i = 1, 2, 3). Let {$a_n$},{$b_n$} and {$c_n$} are three real sequences in [0, 1] such that $\in{\leq}\;a_n,\;b_n,\;c_n\;{\leq}\;1-\in$ for $n{\in}N$ and some ${\in}{\geq}0$. Starting with arbitrary $x_1{\in}K$, define sequence {$x_n$} by setting {$$x_{n+1}=P((1-a_n)x_n+a_nT_1(PT_1)^{n-1}y_n)$$ $$y_n=P((1-b_n)x_n+a_nT_2(PT_2)^{n-1}z_n)$$ $$z_n=P((1-c_n)x_n+c_nT_3(PT_3)^{n-1}x_n)$$. Assume that one of the following conditions holds: (1) E satises the Opial property, (2) E has Frechet dierentiable norm, (3) $E^*$ has Kedec -Klee property, where $E^*$ is dual of E. Then sequence {$x_n$} converges weakly to some p${\in}$F(T).

• World Technopolis Review
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• 제2권2호
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• pp.96-108
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• 2013

Egypt has been known as the light house of science and innovation not only in the Middle East but to the world across ages. Recently, there have been many ups and downs that positioned Egypt in a lower rank that it actually deserves according to its long history. This review entitles the current condition of science, technology and innovation in Egypt and the consequent setting up of best practices of science and technology parks (STPs) experiences. Egypt's science, technology and innovation (STI) system is highly centralized and dominated by the public sector, with R&D happening mostly in state-run universities and research centers supervised by the Ministry of Higher Education and Ministry of Scientific Research. R&D indicators state that Egypt ranking is 40th worldwide for the published articles (around 10,000 papers in 2011), while the numbers of issued patents (350 local and 50 international in 2011) is still far beyond expected. STPs in Egypt are addressed in this review by three examples; smart village in Cairo, Investment zone in Borg El-Arab City and Technology Valley in Ismailia. The three models are discussed in details and a suggested road map for developing more STPs is estimated.

• 대한간호학회지
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• 제6권2호
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• pp.10-17
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• 1976

High turnover rate of nurses working in the hospitals is one of the serious problems in nursing society at the present time which can result in reducing the economic condition of hospital and providing low quality nursing care. This study was designed identify the causes and turnover rate of 248 clinical staff nurses in relation to their rewards and incentives in 6 hospitals located in Seoul from Oct.1 to Oct. 20, 1975. Questionnaires and analyzing items were formulated on the basic of Mallow's hierarchy of basic needs which were grouped in three categories such as safety and social and psychological rewards and incentives. The data were analyzed by means of mean, Chi square, Percentage and F- ratio. The following results were obtained: 1) There were 69% of respondents who have definitely decided or hoped to leave the hospital. 2) Those who are in the range of 26 to 30 years of age showed the strongest desire to leave the hospital. 3) There was no significant difference between those who want to leave the hospital and those who want to remain in relation to age, educational background, past experience and expecting period of clinical work. However, the married nurses tend to remain in the hospital than the single. 4) When the rewards scores in the three categories were calculated, psychological rewards were placed in the first rank by the mean score 14.09 ; and each of safety rewards and social rewards were 9.06 and 4.84. When the scores in three categories were compared it was found that there was significant difference. (F〈0.01).

• 대한수학회지
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• 제53권2호
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• pp.331-346
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• 2016

The primary aim of this paper is to generalize a theorem of Hirzebruch for the complex 2-dimensional Bott manifolds, usually called Hirzebruch surfaces, to more general Bott towers of height n. To do so, we first show that all complex vector bundles of rank 2 over a Bott manifold are classified by their total Chern classes. As a consequence, in this paper we show that two Bott manifolds $B_n({\alpha}_1,{\ldots},{\alpha}_{n-1},{\alpha}_n)$ and $B_n({\alpha}_1,{\ldots},{\alpha}_{n-1},{\alpha}_n^{\prime})$ are isomorphic to each other, as Bott towers if and only if both ${\alpha}_n{\equiv}{\alpha}_n^{\prime}$ mod 2 and ${\alpha}_n^2=({\alpha}_n^{\prime})^2$ hold in the cohomology ring of $B_{n-1}({\alpha}_1,{\ldots},{\alpha}_{n-1})$ over integer coefficients. This result will complete a circle of ideas initiated in [11] by Ishida. We also give some partial affirmative remarks toward the assertion that under certain condition our main result still holds to be true for two Bott manifolds just diffeomorphic, but not necessarily isomorphic, to each other.

• 한국소음진동공학회논문집
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• 제13권11호
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• pp.890-896
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• 2003

It is said that the goal of the design of good acoustical environment is at first the reduction of undesirable sounds. and in addition the introduction of desirable sounds by which our minds are soothed. The task of creating the desirable sounds leads to the realization of a comfortable acoustic environment and the design of soundscape. It may be an important starting point of soundscape design to select suitable sounds for the target spaces. because each space has a different surrounding condition and requires a special ambient sound. This paper aims to survey preference of the environmental sounds suitable for the public spaces in urban areas such as parks. bus terminals. 35 kinds of natural sounds are. rated by 26 pairs of adjectives. The results of psycho-acoustic experiments are as follows. 1. The proper adjectives for expressing the environmental sounds are classified into 6 groups of comfort, pleasure, fullness. variety, distinctness. and naturalness. 2. Bird singing. murmuring of a stream, artificial sounds. singing of insects and animals are the affirmative rank of preference. 3. Green musics consisted of music and natural sounds are preferred to the pure natural sounds. 4. Sound level relative to background noise causes various preferences to natural sounds in public spaces.

• Nutrition Research and Practice
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• 제11권1호
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• pp.70-75
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• 2017

BACKGROUND: Immigration to South Korea from neighboring Asian countries has risen dramatically, primarily due to marriage between Korean men and foreign women. Although Filipino women rank fourth among married immigrant women, little is known about the health condition of this population. This manuscript focuses on the design and methods of Filipino women's diet and health study (FiLWHEL). SUBJECTS/METHODS: FiLWHEL is a cohort of Filipino women married to Korean men, aged 19 years old or over. The data collection comprised three parts: questionnaire, physical examination, and biospecimen collection. Questionnaires focused on demographic factors, diet, other health-related behaviors, acculturation and immigration-related factors, medical history, quality of life, and children's health information. Participants visited the recruitment site and answered the structured questionnaires through a face-to-face interview. We also measured their anthropometric features and collected fasting blood samples, toenails, and DNA samples. Recruitment started in 2014. RESULTS/CONCLUSIONS: Collection of data is ongoing, and we plan to prospectively follow our cohort participants. We expect that our study, which is focused on married Filipino women immigrants, can elucidate nutritional/health status and the effects of transitional experiences from several lifestyle factors.

• 한국조경학회지
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• 제22권3호
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• pp.121-135
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• 1994

The Purpose of this study was to obtain data about management of the landscape plants and facility in APT. complex. Because of be completed 2 years ago, landscape plants ware damaged by transplantation and lost the nature tree shape. As well, the management conditions of plants and facility were wholly bad. In details, tree-species consisted of 52 species arbors and 35 species shrubs in APT. complex. The high rank 5 species were planted as main plants. The rates were 45.6-62.8% in arbors and 81.8-97.0% in shrubs. In the degree of tree shape and damage by diseuse and pest, the bad level of 1-2points were ranked highly as 13.9% and 10.4%. In the degree of tree shape and damage by disease and pest, the bad level of 1-2points were showed as 5.1% and 4.7%. In the interview Survey, the main problems of management-maintenance were expressed deficiency of budget, specialist and concern of residents. In the future, methods for the intensive management of APT. complex; First, the management of landscape plants and facility should be attained by a expert and need to establishment of maintenance scheme thoroughly. Above all, for improvement of residential life, we should be lead to convert of a resident recognition in the management -maintenance of exterior space.