• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.80-80
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• 2003

${\beta}$-lapachone(${\beta}$-Lap), a natural o-naphthoquinone, presents in the bark of the Lapacho tree. ${\beta}$-Lap is cytotoxic against a variety of human cancer cells and it potentiates the anti-tumor effect of Taxol. In addition, ${\beta}$-Lap has been reported to radiosensitize cancer cells by inhibiting the repair of radiation-induced DNA damage.In the present study, we investigated the cytotoxicity of ${\beta}$-Lap against RKO human colorectal cancer cells as well as the combined effect of ${\beta}$-LaP and ionizing radiation. An incubation of RKO cells with 5 ${\mu}$M of ${\beta}$-Lap for 4 h killed almost 90％ of the clonogenic cells. An incubation of RKO cells with 5 ${\mu}$M of ${\beta}$-Lap for 4 h or longer also caused massive apoptosis. Unlike other cytotoxic agents, ${\beta}$-Lap did not increase the expression of p53 and p21 and it suppressed the NFkB expression. The expression of Caspase 9 and 3 was minimally altered by ${\beta}$-Lap. Radiation and ${\beta}$-Lap acted synergistically in inducing clonogenic cell death and apoptosis in RKO cells when ${\beta}$-Lap treatment was applied after but not before the radiation exposure of the cells. Interestingly, a 4 h treatment with 5 ${\mu}$M of ${\beta}$-Lap starting 5 h after irradiation was as effective as that starting immediately after irradiation. The mechanisms of ${\beta}$-Lap-induced cell killing is controversial but a recent hypothesis is that ${\beta}$-Lap is activated by NAD(P)H: quinone-onidoreductase (NQO1) in the cells followed by an elevation of cytosolic Ca$\^$2+/ level and activation of proteases leading to apoptosis. It has been reported that NQO1 level in cells is markedly up-regulated for longer than 10 h after irradiation. Indeed, using immunological staining of NQO1, we observed a significant elevation of NQO1 expression in RKO cells 5h after 2-4 Gy irradiation. Such a prolonged elevation of NQO1 level after irradiation may be the reasons why the ${\beta}$-Lap treatment applied S h after irradiation was as effective as that applied immediately after irradiation in killing the cells. In view of the fact that the repair of radiation-induced damage is usually completed within 1-2 h after irradiation, it is highly likely that the ${\beta}$-Lap treahment applied 5 h after irradiation could not inhibit the repair of radiation-induced damage. For in vivo study, RKO cells were injected S.C. into the hind-leg of Nu/Nu mice, and allowed to grow to 130 mm3 tumor. The mice were i.p. injected with ${\beta}$-lapachone or saline 2 h after irradiation of tumors with 10 Gy of X-rays. The radiation induced growth delay was increased by 2.4 $\mu\textrm{g}$/g of ${\beta}$-lapachone. Taken together, we may conclude that the synergistic interaction of radiation and ${\beta}$-Lap in killing cancer cells is not due to radiosensitization by ${\beta}$-Lap but to an enhancement of ${\beta}$-Lap cytotoxicity by radiation through an upregulation of NQO1. The fact that NQO1 is elevated in tumors and that radiation causes prolonged increase of the NQO1 expression may be exploited to preferentially kill tumor cells using ${\beta}$-Lap in combination with radiotherapy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.667-673
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• 2005

The purposes of this study were 1) to analyze the preference of leadership style among ${\lceil}$Transformational leadership$\rfloor$ and ${\lceil}$Service leadership$\rfloor$, 2) to examine the differences of the job satisfaction between the high level of service leadership group and low level of the service leadership group and 3) to testify the hypothesis that the service leadership and its 4 elements (belief, attitude, ability, insight) affect the job satisfaction. The questionnaires were developed to measure the service leadership, the preference of leadership style (transfer-mational leadership and service leadership) and Job satisfaction. The surveys were distributed to 120 managers and employees in the family restaurant in Korea, and 104 questionnaires were responded (response rate: $86.7\%$). The SPSS 12.0 package program was used to conduct the descriptive analysis, correlation analysis, t-test and multiple regression analysis. The result of leadership style preference showed the followers preferred the service leadership $(75.0\%)$ to the transformational leadership $(25.0\%)$. Comparing the job satisfaction of high level of service leadership group and that of low level of service leadership group, the job satisfaction of high level of service leadership group was significantly (p<0.001) higher than that of low level of service leadership group (high level of service leadership group: 4.03, low service leadership group: 3.27, measured on a 5-point likert scale). All three factors of job satisfaction (human factor, service system and company image) in high level of leadership group were significantly (p<0.001) higher than those of lower level of service leadership group. The result of multiple regression analysis presented that the service leadership and it's 4 elements (concept, mind, skill, insight) have significant (p=0.000) effects on the job satisfaction. As a conclusion, we examined theoretical framework of service leadership model and testified the applicability in the field of family restaurants. But the service leadership was the new conceptual theory, so there should be the more empirical studies on managers and employees in the service industry.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.32-41
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• 1991

This study is focusted to the national park of Korean typical mountain Chi-ri, its visual resources of forests, and practiced inspectind course by way of hypothesis and tests, to show visual resource management objectively, and that of quantitative basic data. spatial image structure measured by Semantic Differential(S.D.) Scale was shown through factor analysis algorithm for the analyzing psychological amount and examined the flowing out of decisive factor and the objective importance related mutual factors by appling the measurement of visual quality. Also, it has been investigated the differences between the degrees of expectation which is used before and of satisfaction which is used, by appling instrumental expectation theory. And showed patterns of investigation area through factor analyzing algorithm. As a national Park, visual factors that have natural landscape harmonized forest, sky, surface of the water, curious stones and rocks, temples should be escalate their values affirmatively so as to be the scenery of pointed direction and enjoyable, and it is needs the techniques visual resource management and its controlling technique to make artificial structures more intentional planning and systemical setting. Manmade distinctive quality in the spatials that affect complementally or harmonizingly, should be received considering relations between the distifution and joining which in line with various visual presenting massive factors. More than that, it is needed united basic standard to the beauty of arrangements which contain visual continuity considered balance between nature and human work, simplicity of structural types, assimilation, emphasis, unification of different factors and pro rata.

• Journal of Korean Academy of Nursing
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• v.29 no.1
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• pp.161-173
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• 1999

The purpose of this study was to develope and test the structural model for quality of life in women having hysterectomies. A hypothetical model was constructed on the basis of previous studies and a review of literature. The conceptual framework was built around eight constructs. Exogenous variables included in this model were marital intimacy, importance of uterus, professional support, positive coping behavior and pre-operative symptoms. Endogenous variables were spouse's support, sense of loss and quality of life. Empirical data for testing the hypothetical model was collected using a self-report questionnare from 203 women having hysterectomies at the outpatient clinics of four general hospitals and a mail survey in Pusan City. The Data was collected from December, 1997 to January, 1998. Reliability of the eight instruments was tested with Cronbach's alpha which ranged from 0.639-0.915. For the data analysis, SPSS 7.5 WIN Program and LISREL 8.12 WIN Program were used for descriptive statistics and covariance structural analysis. The results of covariance structure analysis were as follows : 1. Hypothetical model showed a good fit with the empirical data. ［$\chi$$^2$＝6.93(df＝5, P＝.23), GFI＝.99, AGFI＝.94, RMSR＝.019, NNFI＝.97, NFI＝.98, CN＝440, standardized residuals(-2.14-2.10)］ 2. For the parsimony of model, a modified model was constructed by deleting 3 paths and adding 1 path according to the criteria of statistical significance and meaning. 3. The modified model also showed a good fit with the data. ［$\chi$$^2$＝5.26(df＝7, P＝.63), GFI＝.99, AGFI＝.97, RMSR＝.014, NNFI＝1.02, NFI＝.99, CN＝710, standardized residuals(-1.46-1.70)］ Results of the testing of the hypothesis were as follows : 1. Marital intimacy(${\gamma}$11＝.78, t＝14.37) and professional support(${\gamma}$13＝.12, t＝2.12) had a significant direct effect on the spouse's support. 2. Pre-operative symptoms(${\gamma}$25＝.32, t＝3.12), importance of uterus(${\gamma}$22＝.20, t＝2.61) and spouse's support($\beta$2l＝-.19, t＝-2.43) had a significant direct effect on the sense of loss. 3. Sense of loss($\beta$32＝-.66, t＝-9.83) had a direct effect on the quality of life. Marital intimacy had a direct(${\gamma}$31＝.19, t＝3.33), indirect(${\gamma}$31＝.14, t＝2.52) and total effect(${\gamma}$31＝.25, t＝4.41) on the quality of life. Professional support had a direct effect(${\gamma}$33＝.11, t＝2.07) and total effect(${\gamma}$33＝.13, t＝2.31) on the quality of life. The direct effect of pre-operative symptoms(${\gamma}$35＝-.36, t＝4.02) and positive coping behavior(${\gamma}$34＝.15, t＝2.06) had the insignificant effect on the quality of life while, due to the idirect effect these variables had overall significant effect on the quality of life. The results of this study showed that the sense of loss had the most significant direct effect on the quality of life. Marital intimacy, pre -operative symptoms and spouse's support had a significant direct effect on this sense of loss. These four variables, the sense of loss, marital intimacy, pre-operative symptoms and spouse's support, were identified as relatively important variables. The results of this study suggested that there is needed to determine if nursing intervention would alleviate this sense of loss and promote a greater quality of life in women who have had hysterectomies.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.52-58
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• 2001

Objectives: An Increased level of psychophysiologic arousal and diminished physiologic flexibility would be observed in patients with panic disorder compared with a normal control group. We investigated the differences of psychophysiologic response between patients with panic disorder and normal control to examine this hypothesis. Methods: Ten Korean patients with panic disorder who met the diagnostic criteria of DSM-IV were compared with 10 normal healthy subjects. In psychological assessment, levels of anxiety and depression were evaluated by State-Trait Anxiety Inventory, Beck's Depression Inventory and Hamilton Rating Scale For Anxiety and Depression. Heart rate, respiration rate, electrodermal response, and electromyographic activity were measured by biofeedback system (J & J I-330 model) to determine psychophysiologic responses on autonomic nervous system. Stressful tasks included mental arithmetic, video game, hyperventilation, and talking about a stressful event. Psychophysiologic responses were measured according to the following procedures : baseline(3 min)-mental arithmetic (3 min)-rest (3 min)-video game (3 min)-rest (3 min)-hyperventilation (3 min)-rest (3 min)-talking about a stressful event (3 min). Results: The baseline level of anxiety and depression, electrodermal response (p=.017), electromyographic activity (p=.047) and heart rate (p=.049) of patients with panic disorder were significantly higher than those of the normal subject group. In electrodermal response, patient group had significantly higher startle response than the control group during hyperventilation (p=.001). Startle and recovery responses of heart rate in the patient group were significantly lower than responses in the control group during mental arithmetic (p=.007, p=.002). In electrodermal response of the patient group, startle response was significantly higher than recovery response during mental arithmetic (p=.000) and video game task (p=.021). Recovery response was significantly higher than startle response in respiratory response during hyperventilation. Conclusion: The results showed that patients with panic disorder had higher autonomic arousal than the control group, but the physiologic flexibility was variable. We suggest that it is helpful for treatment of panic disorder to decrease the level of autonomic arousal and to recover the physiologic flexibility in certain stressful event.

• Sleep Medicine and Psychophysiology
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• v.13 no.2
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• pp.45-51
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• 2006

Obstructive sleep apnea (OSA) syndrome disrupts normal sleep. However, there were few studies to evaluate the asymmetric distribution, the one of the important factors of normal sleep in OSA subjects. We hypothesized that asymmetry would be broken in OSA patients. 49 male subjects with the complaint of heavy snoring were studied with polysomnography. We divided them into two groups based on the apnea-hypopnea index (AHI) fifteen: 13 simple snoring group (SSN, average AHI $5.9{\pm}4.4$) and 32 OSA group (average AHI $47.3{\pm}23.9$). We compared split sleep variables between the first half and the second half of sleep within each group with paired t-test for the evaluation of asymmetry. Changes of sleep architecture of OSA were higher stage 1 sleep% (S1), total arousal index (TAI), AHI, and mean heart rate (HR) and lower stage 2 sleep% (S2), REM sleep%, and mean arterial O2 saturation (SaO2) than SSN subjects. SWS and wake time after sleep onset (WASO) were not different between two groups. In split-night analysis, OSA subjects showed higher S2, slow wave sleep% (SWS), spontaneous arousal index (SAI), and mean HR in the first half, and higher REM sleep% and mean SaO2 in the second half. Those were same pattern as in SSN subjects. Mean apnea duration and longest apnea duration were higher in the second half only in the OSA. No differences of AHI, ODI, WASO, and S1 were found between the first and the second half of sleep in both groups. TAI was higher in the first half only in the SSN. SWS and WASO seemed to be influenced sensitively by simple snoring as well as OSA. Unlike our hypothesis, asymmetric distributions of major sleep architecture variables were preserved in OSA group. Losing asymmetry of TAI might be related to pathophysiology of OSA. We need more studies that include large number of subjects in the future.

• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.33-40
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• 2020

The purpose of this research was to find out the relation between Korean learners' English proficiency and the ratio of the length of the stressed vowel in a monosyllabic noun to that of the unstressed vowel in an article of the noun phrases (e.g., "a cup", "the bus", etcs.). Generally, the vowels in monosyllabic content words are phonetically more prominent than the ones in monosyllabic function words as the former have phrasal stress, making the vowels in content words longer in length, higher in pitch, and louder in amplitude. This study, based on the speech samples from Korean-Spoken English Corpus (K-SEC) and Rated Korean-Spoken English Corpus (Rated K-SEC), examined 879 English noun phrases, which are composed of an article and a monosyllabic noun, from sentences which are rated on 4 levels of proficiency. The lengths of the vowels in these 879 target NPs were measured and the ratio of the vowel lengths in nouns to those in articles was calculated. It turned out that the higher the proficiency level, the greater the mean ratio of the vowels in nouns to the vowels in articles, confirming the research's hypothesis. This research thus concluded that for the Korean English learners, the higher the English proficiency level, the better they could produce the stressed and unstressed vowels with more conspicuous length differences between them.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.395-403
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• 1993

Background: The cell cycle is composed of a series of steps which can be negatively or positively regulated by various factors. Alteration or inactivation of p53 by mutations, or by its interactions with oncogene products of DNA tumor viruses, can lead to cancer. Mutations of the p53 gene occur frequently in human primary lung cancers and the wild-type p 53 allele is often concomitantly deleted. These suggest that deprivation of suppressive role of the wild-type p53 may ensure tumor cell growth presumable by the mutant p53 gene. Methods: In an attempt to investigate this hypothesis, a mutant p53 gene was immunohistochemically demonstrated in the formalin-fixed paraffin-embedded tissue sections of lung cancers by using a monoclonal antibody p53 (Ab-3 and clone DO7). Results: The expression of p53 (DO7) was found in all four normal lung tissues, four small cell carcinomas, and four non small cell carcinomas in histologic types of lung cancer. In the six normal lung tissues the expressions of p53 (Ab-3) were not found. Contrarily, the expression of p53 (Ab-3) was found in the nuclei of lung cancers among fifteen (46.9%) of thirty-two cases studied. The expression of p53 (Ab-3) was disclosed in three case (37.5%) of eight small cell carcinomas and twelve cases (50.0%) of twenty-four non small cell carcinomas in histologic types of lung cancer. Conclusion: These findings suggest that expression of the mutant p53 is related to the one of events in the pathogenesis of human lung cancer and the role of the other oncogenes might be also related to the development of lung cancers.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.43-65
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• 2010

Facing a complex environment driven by a decade, many companies are adopting new strategic frameworks such as Customer Relationship Management system to achieve sustainable profitability as well as overcome serious competition for survival. In many business areas, CRM system advanced a great deal in a matter of continuous compensating the defect and overall integration. However, pharmaceutical companies in Korea were slow to accept them for usesince they still have a tendency of holding fast to traditional way of sales and marketing based on individual networks of sales representatives. In the circumstance, this article tried to empirically address current status of CRM system as well as the effects of the system on the performance of pharmaceutical companies by applying BSC method's four perspectives, from financial, customer, learning and growth and internal process. Survey by e-mail and post to employers and employees who were working in pharma firms were undergone for the purpose. Total 113 cases among collected 140 ones were used for the statistical analysis by SPSS ver. 15 package. Reliability, Factor analysis, regression were done. This study revealed that CRM system had a significant effect on improving financial and non-financial performance of pharmaceutical companies as expected. Proposed regression model fits well and among them, CRM marketing information system shed the light on substantial impact on companies' outcome given profitability, growth and investment. Useful analytical information by CRM marketing information system appears to enable pharmaceutical firms to set up effective marketing and sales strategies, these result in favorable financial performance by enhancing values for stakeholderseventually, not to mention short-term profit and/or mid-term potential to growth. CRM system depicted its influence on not only financial performance, but also non-financial fruit of pharmaceutical companies. Further analysis for each component showed that CRM marketing information system were able to demonstrate statistically significant effect on the performance like the result of financial outcome. CRM system is believed to provide the companies with efficient way of customers managing by valuable standardized business process prompt coping with specific customers' needs. It consequently induces customer satisfaction and retentionto improve performance for long period. That is, there is a virtuous circle for creating value as the cornerstone for sustainable growth. However, the research failed to put forward to evidence to support hypothesis regarding favorable influence of CRM sales representative's records assessment system and CRM customer analysis system on the management performance. The analysis is regarded to reflect the lack of understanding of sales people and respondents between actual work duties and far-sighted goal in strategic analysis framework. Ordinary salesmen seem to dedicate short-term goal for the purpose of meeting sales target, receiving incentive bonus in a manner-of-fact style, as such, they tend to avail themselves of personal network and sales and promotional expense rather than CRM system. The study finding proposed a link between CRM information system and performance. It empirically indicated that pharmaceutical companies had been implementing CRM system as an effective strategic business framework in order for more balanced achievements based on the grounded understanding of both CRM system and integrated performance. It suggests a positive impact of supportive CRM system on firm performance, especially for pharmaceutical industry through the initial empirical evidence. Also, it brings out unmet needs for more practical system design, improvement of employees' awareness, increase of system utilization in the field. On the basis of the insight from this exploratory study, confirmatory research by more appropriate measurement tool and increased sample size should be further examined.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.3
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• pp.41-52
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• 2010

The purpose of this paper is to evaluate visitor satisfaction(VS) in waterfront parks in terms of resources, facilities, embodiment of theme(ET), site composition(SC), relaxation activity space(RAS), and dynamic activity space(DAS), which are supply-side components in the planning process of waterfront parks, in order to answer the research question; 'How is visitor satisfaction of waterfront parks determined?' After reviewing the literature on parks and the building process of waterfront parks in Korea, we constructed a conceptual framework and have ascertained a research hypothesis. We had obtained data through a questionnaire survey from 327 visitors at waterfront parks, based on the quota sampling method. We have analyzed the data using the path analysis method. We found that: 1) The direct effects of resources and facilities on VS turned out to be 0.273 and 0.306, respectively while the indirect effects are 0.114, 0.170, respectively. 2) The direct effects of SC, as a component of the planning process on VS, turned out to be 0.243 while that of ET had no affect on VS. The indirect effect of ET and SC on VS turned out to be 0.059 and 0.018, respectively. 3) The direct effects of RAS on VS turned out to be 0.129 while the indirect effects of RAS and DAS on VS turned out to be 0.002 and 0.017, respectively. 4) The size of causal effect, in order, were facilities, resources, SC, RAS, ET, and DAS. 5) Resources and facilities, as a park foundation, compose 64.84 percent of total causal effect while ET and SC have 24.04 percent and RAS and DAS have 11.12 percent, respectively. These research results imply that: 1) Existing waterfront parks should be regenerated with the embodiment of water related theme and with improved facilities for RAS and visitor programs and/or facilities for DAS. 2) The relationship among ET, SC, RAS and DAS should be increased for a significant improvement of VS, and 3) A process-oriented approach turned out to be highly useful for the development of substantive theory and methodology. It is recommended that a structural equation model on waterfront parks be developed using more empirical data and this approach be widely applied for testing its validity.