• 제목/요약/키워드: Long term data

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The Changes of Plasma Catecholamines Concentration during Waking and Sleep in Obstructive Sleep Apnea Syndrome Patients with Systemic Hypertension (전신성 고혈압을 동반한 폐쇄성 수면 무호흡증후군 환자에서 각성시와 수면중의 혈장 Catecholamines 농도 변화)

  • Moon, Hwa Sik;Lo, Dae Guen;Choi, Young Mee;Kim, Young Kyoon;Kim, Kwan Hyoung;Song, Jeong Sup;Park, Sung Hak
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.4
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    • pp.600-612
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    • 1996
  • Background : Recent studies deported that untreated patients with obstructive sleep apnea syndrome had high long-term mortality rates, and cardiovascular complications of these patients clad a major effect on mortality. Several data indicates that obstructive sheep apnea syndrome contributes to the development of diurnal systemic hypertension. But the pathophysiological mechanism of the development of systemic hypertension in these patients is still uncertain. This study was performed to evaluate the possible role of sympathetic nervous system activity for the development of systemic hypertension in patients with obstructive sleep apnea syndrome. Method : 35 patients with obstructive sleep apnea syndrome(OSAS) and 13 Control subjects(control) were included in this study. 21 patients of OSAS were normotensives(OSAS-NBP), and 14 patients of OSAS were hypertensives(OSAS-HBP). Full night polysomnography was undertaken to all subjects. We measured plasma norepinephrine(NE) and epinephrine(EP) concentrations during waking and sleep, using high performance liquid chromatography, in all patients and control subjects. Results : In OSAS, OSAS-NBP and control, plasma NE and EP concentrations during sleep were lowed than during waking(p<0.01). But, in OSAS-HBP, these was no difference between during waking and sleep. Plasma NE concentrations during sleep of OSAS, OSAS-NBP and OSAS-HBP were higher than Control(p<0.05). In OSAS-HBP, daytime systolic blood pressure correlated with plasma NE concentration during sleep(r=0.7415, p<0.01), arid correlated inversely with mean arterial oxygen saturation(r=-0.6465, p<0.05) or arterial oxygen saturation nadir(r=-0.6) 14, p<0.05) during sleep. Conclusion : The sympathetic activity during sleep of obstructive sleep apnea syndrome patients was higher than control subjects. In obstructive sleep apnea syndrome patients with systemic hypertension, there was no diurnal variation of sympathetic activity, and there was correlation between daytime systolic blood pressure and sympathetic activity during sleep. These data suggests that chronic hyperactivity of sympathetic nervous system may contribute to the development of diurnal systemic hypertension in patients with obstructive sleep apnea syndrome.

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Preparation of Pure CO2 Standard Gas from Calcium Carbonate for Stable Isotope Analysis (탄산칼슘을 이용한 이산화탄소 안정동위원소 표준시료 제작에 대한 연구)

  • Park, Mi-Kyung;Park, Sunyoung;Kang, Dong-Jin;Li, Shanlan;Kim, Jae-Yeon;Jo, Chun Ok;Kim, Jooil;Kim, Kyung-Ryul
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.1
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    • pp.40-46
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    • 2013
  • The isotope ratios of $^{13}C/^{12}C$ and $^{18}O/^{16}O$ for a sample in a mass spectrometer are measured relative to those of a pure $CO_2$ reference gas (i.e., laboratory working standard). Thus, the calibration of a laboratory working standard gas to the international isotope scales (Pee Dee Belemnite (PDB) for ${\delta}^{13}C$ and Vienna Standard Mean Ocean Water (V-SMOW) for ${\delta}^{18}O$) is essential for comparisons between data sets obtained by other groups on other mass spectrometers. However, one often finds difficulties in getting well-calibrated standard gases, because of their production time and high price. Additional difficulty is that fractionation processes can occur inside the gas cylinder most likely due to pressure drop in long-term use. Therefore, studies on laboratory production of pure $CO_2$ isotope standard gas from stable solid calcium carbonate standard materials, have been performed. For this study, we propose a method to extract pure $CO_2$ gas without isotope fractionation from a solid calcium carbonate material. The method is similar to that suggested by Coplen et al., (1983), but is better optimized particularly to make a large amount of pure $CO_2$ gas from calcium carbonate material. The $CaCO_3$ releases $CO_2$ in reaction with 100% pure phosphoric acid at $25^{\circ}C$ in a custom designed, evacuated reaction vessel. Here we introduce optimal procedure, reaction conditions, and samples/reactants size for calcium carbonate-phosphoric acid reaction and also provide the details for extracting, purifying and collecting $CO_2$ gas out of the reaction vessel. The measurements for ${\delta}^{18}O$ and ${\delta}^{13}C$ of $CO_2$ were performed at Seoul National University using a stable isotope ratio mass spectrometer (VG Isotech, SIRA Series II) operated in dual-inlet mode. The entire analysis precisions for ${\delta}^{18}O$ and ${\delta}^{13}C$ were evaluated based on the standard deviations of multiple measurements on 15 separate samples of purified $CO_2$. The pure $CO_2$ samples were taken from 100-mg aliquots of a solid calcium carbonate (Solenhofen-ori $CaCO_3$) during 8-day experimental period. The multiple measurements yielded the $1{\sigma}$ precisions of ${\pm}0.01$‰ for ${\delta}^{13}C$ and ${\pm}0.05$‰ for ${\delta}^{18}O$, comparable to the internal instrumental precisions of SIRA. Therefore, we conclude the method proposed in this study can serve as a way to produce an accurate secondary and/or laboratory $CO_2$ standard gas. We hope this study helps resolve difficulties in placing a laboratory working standard onto the international isotope scales and does make accurate comparisons with other data sets from other groups.

A Case Study on Application of the Menu Engineering Technique in Government Offices Contract Foodservice (관공서급식소의 메뉴엔지니어링기법을 적용한 메뉴분석 사례연구)

  • Rho, Sung-Yoon
    • Journal of Nutrition and Health
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    • v.42 no.1
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    • pp.78-96
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    • 2009
  • The purpose of this study was to analyze and evaluate the menu served in government offices foodservice by using Kasavana & Smith's Menu-Engineering. Sales and food costs were collected from the daily sales reports for a year from Jan 2 to Dec 31 in 2007. Calculation for menu analysis and customer's data were done by computer using the MS 2003 Excel spreadsheet program and SPSS 12.0 package program. Menu mix% (MM%) and unit contribution margin were used as variables by Kasavana & Smith. Four possible classifications by Menu-Engineering technique were turned out as 'STAR', 'PLOWHORSE', 'PUZZLE', 'DOG'. The main menus served during a year were 128 dishes and about 141 peoples visited this restaurant daily. The mean age of the men was $44.1\;{\pm}\;6.3$, women were $32.7\;{\pm}\;6.4$ and showed that was statistically higher than that of women (p < .0001). The rates of STAR menus were 'Western style (75.0%)', 'guk/tang-ryu (48.1%)', 'jjigae/ jeongol-ryu (23.1%)', 'bap-ryu (17.2%)' in sequence. There were no STAR menus in gui/jorim/jjim-ryu. PLOWHORSE menus were 'gui-ryu (75.0%)', 'guk/tang-ryu (29.6%)', 'bap-ryu (27.6%)' in sequence. There were no PUZZLE or DOG menus in 'jjigae/jeongol-ryu'. PUZZLE menus were 'jorim/jjim-ryu and Myeonryu (each 33.3%)', 'bap-ryu (31.0%)' in sequence. PUZZLE menus were a lots of 'Chinese food (75.0%)' and 'myeonryu (55.6%)'. This study provides the basic data based on regularly menu analysis method applied the scientific menu analysis techniques in government offices food services, I'd like to suggest that the menu management must be done based on the necessity and result of menu analysis according to the seasonal and middle, long-term plans.

The Impact of Conflict and Influence Strategies Between Local Korean-Products-Selling Retailers and Wholesalers on Performance in Chinese Electronics Distribution Channels: On Moderating Effects of Relational Quality (중국 가전유통경로에서 한국제품 현지 판매업체와 도매업체간 갈등 및 영향전략이 성과에 미치는 영향: 관계 질의 조절효과)

  • Chun, Dal-Young;Kwon, Joo-Hyung;Lee, Guo-Ming
    • Journal of Distribution Research
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    • v.16 no.3
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    • pp.1-32
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    • 2011
  • I. Introduction: In Chinese electronics industry, the local wholesalers are still dominant but power is rapidly swifting from wholesalers to retailers because in recent foreign big retailers and local mass merchandisers are growing fast. During such transient period, conflicts among channel members emerge important issues. For example, when wholesalers who have more power exercise influence strategies to maintain status, conflicts among manufacturer, wholesaler, and retailer will be intensified. Korean electronics companies in China need differentiated channel strategies by dealing with wholesalers and retailers simultaneously to sell more Korean products in competition with foreign firms. For example, Korean electronics firms should utilize 'guanxi' or relational quality to form long-term relationships with whloesalers instead of power and conflict issues. The major purpose of this study is to investigate the impact of conflict, dependency, and influence strategies between local Korean-products-selling retailers and wholesalers on performance in Chinese electronics distribution channels. In particular, this paper proposes effective distribution strategies for Korean electronics companies in China by analyzing moderating effects of 'Guanxi'. II. Literature Review and Hypotheses: The specific purposes of this study are as follows. First, causes of conflicts between local Korean-products-selling retailers and wholesalers are examined from the perspectives of goal incongruence and role ambiguity and then effects of these causes are found out on perceived conflicts of local retailers. Second, the effects of dependency of local retailers upon wholesalers are investigated on local retailers' perceived conflicts. Third, the effects of non-coercive influence strategies such as information exchange and recommendation and coercive strategies such as threats and legalistic pleas exercised by wholesalers are explored on perceived conflicts by local retailers. Fourth, the effects of level of conflicts perceived by local retailers are verified on local retailers' financial performance and satisfaction. Fifth, moderating effects of relational qualities, say, 'quanxi' between wholesalers and retailers are analyzed on the impact of wholesalers' influence strategies on retailers' performances. Finally, moderating effects of relational qualities are examined on the relationship between conflicts and performance. To accomplish above-mentioned research objectives, Figure 1 and the following research hypotheses are proposed and verified. III. Measurement and Data Analysis: To verify the proposed research model and hypotheses, data were collected from 97 retailers who are selling Korean electronic products located around Central and Southern regions in China. Covariance analysis and moderated regression analysis were employed to validate hypotheses. IV. Conclusion: The following results were drawn using structural equation modeling and hierarchical moderated regression. First, goal incongruence perceived by local retailers significantly affected conflict but role ambiguity did not. Second, consistent with conflict spiral theory, the level of conflict decreased when retailers' dependency increased toward wholesalers. Third, noncoercive influence strategies such as information exchange and recommendation implemented by wholesalers had significant effects on retailers' performance such as sales and satisfaction without conflict. On the other hand, coercive influence strategies such as threat and legalistic plea had insignificant effects on performance in spite of increasing the level of conflict. Fourth, 'guanxi', namely, relational quality between local retailers and wholesalers showed unique effects on performance. In case of noncoercive influence strategies, 'guanxi' did not play a role of moderator. Rather, relational quality and noncoercive influence strategies can serve as independent variables to enhance performance. On the other hand, when 'guanxi' was well built due to mutual trust and commitment, relational quality as a moderator can positively function to improve performance even though hostile, coercive influence strategies were implemented. Fifth, 'guanxi' significantly moderated the effects of conflict on performance. Even if conflict arises, local retailers who form solid relational quality can increase performance by dealing with dysfunctional conflict synergistically compared with low 'quanxi' retailers. In conclusion, this study verified the importance of relational quality via 'quanxi' between local retailers and wholesalers in Chinese electronic industry because relational quality could cross out the adverse effects of coercive influence strategies and conflict on performance.

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An Analysis of the Differences in Management Performance by Business Categories from the Perspective of Small Business Systematization (영세 소상공인 조직화에 대한 직능업종별 차이분석과 경영성과)

  • Suh, Geun-Ha;Seo, Mi-Ok;Yoon, Sung-Wook
    • Journal of Distribution Science
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    • v.9 no.2
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    • pp.111-122
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    • 2011
  • The purpose of this study is to survey the successful cases of small and medium Business Systematization Cognition by examining their entrepreneurial characteristics and analysing the factors affecting their success. To that end, previous studies on the association types of small businesses were studied. A research model was developed, and research hypotheses for an empirical analysis were established upon it. Suh et al. (2010) insist on the importance of Small Business Systematization in Korea but also show that small business performance is suffering: they are too small to stand alone. That is why association is so crucial for them: they must stand together. Unfortunately, association is difficult, as they have few specific links and little motivation. Even in franchising networks, association tends to be initiated by big franchisers, not small ones. In that sense, association among small businesses is crucial for their long-term survival. With this in mind, this study examines how they think and feel about the issue of 'Industrial Classification', how important Industrial Classification is to their business success, and what kinds of problems it raises in the markets. This study seeks the different cognitions among the association types of small businesses from the perspectives of participation motivation, systematization expectation, policy demand level, and management performance. We assume that different industrial classification types of small businesses will have different cognitions concerning these factors. There are four basic industrial classification types of small businesses: retail sales, restaurant, service, and manufacturing. To date, most of the studies in this area have focused on collecting data on the external environments of small businesses or performing statistical analyses on their status. In this study, we surveyed 4 market areas in Busan, Masan, and Changwon in Korea, where business associations consist of merchants, shop owners, and traders. We surveyed 330 shops and merchants by sending a questionnaire or visiting. Finally, 268 questionnaires were collected and used for the analysis. An ANOVA, T-test, and regression analyses were conducted to test the research hypotheses. The results demonstrate that there are differences in cognition depending upon the industrial classification type. Restaurants generally have a higher cognition concerning job offer problems and a lower cognition concerning their competitiveness. Restaurants also depend more on systematization expectation than do the other industrial classification types. On the policy demand level, restaurants have a higher cognition. This study identifies several factors that are contributing to management performance through differences in cognition that depend upon association type: systematization expectation and policy demand level have positive effects on management performance; participation motivation has a negative effect on management performance. We confirm also that the image factors of different cognitions are linked to an awareness of the value of systematization and that these factors show sequential and continual patterns in the course of generating performances. In conclusion, this study carries significant implications in its classifying of small businesses into the four different associational types (retail sales, restaurant, services, and manufacturing). We believe our study to be the first one to conduct an empirical survey in this subject area. More studies in this area will likely use our research frameworks. The data show that regionally based industrial classification associations such as those in rural cities or less developed areas tend to suffer more problems than those in urban areas. Moreover, restaurants suffer more problems than the norm. Most of the problems raised in this study concern the act of 'associating itself'. Most associations have serious difficulties in associating. On the other hand, the area where they have the least policy demand is that of service types. This study contributes to the argument that associating, rather than financial assistance or management consulting, promotes the start-up and managerial performance of small businesses. This study also has some limitations. The main limitation is the number of questionnaires. We could not survey all the industrial classification types across the country because of budget and time limitations. If we had, we could have produced many more useful results and enhanced the precision of our analysis. The history of systemization is very short and the number of industrial classification associations is relatively low in Korea. We should keep in mind, though, that this is very crucial to systemization entrepreneurs starting their businesses, as it can heavily affect their chances of success. Being strongly associated with each other might be critical to the business success of industrial classification members. Thus, the government needs to put more effort and resources into supporting the drive of industrial classification members to become more strongly associated.

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A Study of Factors Associated with Software Developers Job Turnover (데이터마이닝을 활용한 소프트웨어 개발인력의 업무 지속수행의도 결정요인 분석)

  • Jeon, In-Ho;Park, Sun W.;Park, Yoon-Joo
    • Journal of Intelligence and Information Systems
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    • v.21 no.2
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    • pp.191-204
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    • 2015
  • According to the '2013 Performance Assessment Report on the Financial Program' from the National Assembly Budget Office, the unfilled recruitment ratio of Software(SW) Developers in South Korea was 25% in the 2012 fiscal year. Moreover, the unfilled recruitment ratio of highly-qualified SW developers reaches almost 80%. This phenomenon is intensified in small and medium enterprises consisting of less than 300 employees. Young job-seekers in South Korea are increasingly avoiding becoming a SW developer and even the current SW developers want to change careers, which hinders the national development of IT industries. The Korean government has recently realized the problem and implemented policies to foster young SW developers. Due to this effort, it has become easier to find young SW developers at the beginning-level. However, it is still hard to recruit highly-qualified SW developers for many IT companies. This is because in order to become a SW developing expert, having a long term experiences are important. Thus, improving job continuity intentions of current SW developers is more important than fostering new SW developers. Therefore, this study surveyed the job continuity intentions of SW developers and analyzed the factors associated with them. As a method, we carried out a survey from September 2014 to October 2014, which was targeted on 130 SW developers who were working in IT industries in South Korea. We gathered the demographic information and characteristics of the respondents, work environments of a SW industry, and social positions for SW developers. Afterward, a regression analysis and a decision tree method were performed to analyze the data. These two methods are widely used data mining techniques, which have explanation ability and are mutually complementary. We first performed a linear regression method to find the important factors assaociated with a job continuity intension of SW developers. The result showed that an 'expected age' to work as a SW developer were the most significant factor associated with the job continuity intention. We supposed that the major cause of this phenomenon is the structural problem of IT industries in South Korea, which requires SW developers to change the work field from developing area to management as they are promoted. Also, a 'motivation' to become a SW developer and a 'personality (introverted tendency)' of a SW developer are highly importantly factors associated with the job continuity intention. Next, the decision tree method was performed to extract the characteristics of highly motivated developers and the low motivated ones. We used well-known C4.5 algorithm for decision tree analysis. The results showed that 'motivation', 'personality', and 'expected age' were also important factors influencing the job continuity intentions, which was similar to the results of the regression analysis. In addition to that, the 'ability to learn' new technology was a crucial factor for the decision rules of job continuity. In other words, a person with high ability to learn new technology tends to work as a SW developer for a longer period of time. The decision rule also showed that a 'social position' of SW developers and a 'prospect' of SW industry were minor factors influencing job continuity intensions. On the other hand, 'type of an employment (regular position/ non-regular position)' and 'type of company (ordering company/ service providing company)' did not affect the job continuity intension in both methods. In this research, we demonstrated the job continuity intentions of SW developers, who were actually working at IT companies in South Korea, and we analyzed the factors associated with them. These results can be used for human resource management in many IT companies when recruiting or fostering highly-qualified SW experts. It can also help to build SW developer fostering policy and to solve the problem of unfilled recruitment of SW Developers in South Korea.

A Rheological Study on Creep Behavior of Clays (점토(粘土)의 Creep 거동(擧動)에 관한 유변학적(流變學的) 연구(研究))

  • Lee, Chong Kue;Chung, In Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.1 no.1
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    • pp.53-68
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    • 1981
  • Most clays under sustained load exhibit time-dependent deformation because of creep movement of soil particles and many investigators have attempted to relate their findings to the creep behavior of natural ground and to the long-term stability of slopes. Since the creep behavior of clays may assume a variety of forms depending on such factors as soil plasticity, activity and water content, it is difficult and complicated to analyse the creep behavior of clays. Rheological models composed of linear springs in combination with linear or nonlinear dashpots and sliders, are generally used for the mathematical description of the time-dependent behavior of soils. Most rheological models, however, have been proposed to simulate the behavior of secondary compression for saturated clays and few definitive data exist that can evaluate the behavior of non-saturated clays under the action of sustained stress. The clays change gradually from a solid state through plastic state to a liquid state with increasing water content, therefore, the rheological models also change. On the other hand, creep is time-dependent, and also the effect of thixotropy is time-function. Consequently, there may be certain correlations between creep behavior and the effects of thixotropy in compacted clays. In addition, the states of clay depend on water content and hence the height of the specimen under drained conditions. Futhermore, based on present and past studies, because immediate elastic deformation occurs instantly after the pressure increment without time-delayed behavior, the factor representing immediate elastic deformations in the rheological model is necessary. The investigation described in this paper, based on rheological model, is designed to identify the immediate elastic deformations and the effects of thixotropy and height of clay specimens with varing water content and stress level on creep deformations. For these purposes, the uniaxial drain-type creep tests were performed. Test results and data for three compacted clays have shown that a linear top spring is needed to account for immediate elastic deformations in the rheological model, and at lower water content below the visco-plastic limit, the effects of thixotropy and height of clay specimens can be represented by the proposed rheological model not considering the effects. Therefore, the rheological model does not necessitate the other factors representing these effects. On the other hand, at water content higher than the visco-plastic limit, although the state behavior of clays is visco-plastic or viscous flow at the beginning of the test, the state behavior, in the case of the lower height sample, does not represent the same behavior during the process of the test, because of rapid drainage. In these cases, the rheological model does not coincide with the model in the case of the higher specimens.

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Analysis of Prognostic Factors Related to Survival Time for Patients with Small Cell Lung Cancer (소세포폐암 환자의 생존기간에 관련된 인자 분석)

  • Kim, Hee-Kyoo;Yook, Dong-Seung;Shin, Ho-Sik;Kim, Eun-Seok;Lim, Hyun-Jeung;Lim, Tae-Kwan;Ok, Chul-Ho;Cho, Hyun-Myung;Jung, Maan-Hong;Jang, Tae-Won
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.1
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    • pp.57-70
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    • 2003
  • Background : Small cell lung cancer represents approximately 20% of all carcinomas of the lung, and is recognized as having a poor long term outcome compared to non-small cell lung cancer. Therefore, this study investigated the prognostic factors in small cell lung cancer patients in order to improved the survival rate by using the proper therapeutic methods. Material and method : The clinical data from 394 patients who diagnosed with small cell lung cancer and treated from 1993 to 2001 at the Kosin University Gospel Hospital, were analyzed. Result : There were 314 male patients (79.7%), and 80 female patients (20.3%). The number of those with limited disease was 177 (44.9%), and the number of those with extensive disease was 217 (55.1%). Overall, 366 out of 394 enrolled patients had died. The median survival time was 215 days (95% CI : 192-237days). The disease stage, Karnofsky performance state, 5% body weight loss for the recent 3 months, chemotherapy regimens, and the additive chest radiotherapy were identified as being statistically significant factors for the survival time. The median survival times of the supportive care group, one anticancer therapy, and two or more treatment groups were 17 days, 211 days, and 419 day, respectively (p<0.001). These data emphasize the importance of anticancer treatment to improve survival time for patients. The group of concurrent chemoradiotherapy (30 patients) showed significantly longer survival time than the group given sequential chemoradiotherapy (55 patients) (528 days versus 373 days, p=0.0237). The favorable prognostic factors of laboratory study were groups of leukocyte =8,000/mm3, ALP=200 U/L, LDH=450 IU/L, NSE=15 ng/mL, s-GOT=40 IU/L. In extensive disease, there was no difference according to the number of metastatic site. However, the median survival time of patients with ipsilateral pleural effusion had longer than patients having other metastatic sites. According to the survey periods, three groups were divided into 1993-1995, 1996-1998, and 1999-2001. The median survival time was significantly prolonged after 1999 in comparison to previous groups (177 days, 194 days, 289 days, p=0.001, 0.002, respectively). Conclusion: Disease stage and 5% body weight loss for recent 3 months at diagnostic state were significant prognostic factors. In addition, the performance status, serum ALP, LDH, NSE, CEA levels also appear to be prognostic factors. The survival time of those patients with small cell lung cancer has been prologned in recent years. It was suggested that the used of the EP (etoposied and cisplatin) chemotherapy method and concurrent chemoradiotherapy for patients with a limited stage contributed to the improved survival time.

The Influence of Obstructive Sleep Apnea on Systemic Blood Pressure, Cardiac Rhythm and the Changes of Urinary (폐쇄성 수면 무호흡이 전신성 혈압, 심조율 및 요 Catecholamines 농도 변화에 미치는 영향)

  • Lo, Dae-Keun;Choi, Young-Mee;Song, Jeong-Sup;Park, Sung-Hak;Moon, Hwa-Sik
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.1
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    • pp.153-168
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    • 1998
  • Background: The existing data indicate that obstructive sleep apnea syndrome contributes to the development of cardiovascular dysfunction such as systemic hypertension and cardiac arrhythmias, and the cardiovascular dysfunction has a major effect on high long-term mortality rate in obstructive sleep apnea syndrome patients. To a large extent the various studies have helped to clarify the pathophysiology of obstructive sleep apnea, but many basic questions still remain unanswered. Methods: In this study, the influence of obstructive sleep apnea on systemic blood pressure, cardiac rhythm and urinary catecholamines concentration was evaluated. Over-night polysomnography, 24-hour ambulatory blood pressure and ECG monitoring, and measurement of urinary catecholamines, norepinephrine (UNE) and epinephrine (UEP), during waking and sleep were undertaken in obstructive sleep apnea syndrome patients group (OSAS, n=29) and control group (Control, n=25). Results: 1) In OSAS and Control, UNE and UEP concentrations during sleep were significantly lower than during waking (P<0.01). In UNE concentrations during sleep, OSAS showed higher levels compare to Control (P<0.05). 2) In OSAS, there was a increasing tendency of the number of non-dipper of nocturnal blood pressure compare to Control (P=0.089). 3) In both group (n=54), mean systolic blood pressure during waking and sleep showed significant correlation with polysomnographic data including apnea index (AI), apnea-hypopnea index (AHI), arterial oxygen saturation nadir ($SaO_2$ nadir) and degree of oxygen desaturation (DOD). And UNE concentrations during sleep were correlated with AI, AHI, $SaO_2$ nadir, DOD and mean diastolic blood pressure during sleep. 4) In OSAS with AI>20 (n==14), there was a significant difference of heart rates before, during and after apneic events (P<0.01), and these changes of heart rates were correlated with the duration of apnea (P<0.01). The difference of heart rates between apneic and postapneic period (${\Delta}HR$) was significantly correlated with the difference of arterial oxygen saturation between before and after apneic event (${\Delta}SaO_2$) (r=0.223, P<0.001). 5) There was no significant difference in the incidence of cardiac arrhythmias between OSAS and Control In Control, the incidence of ventricular ectopy during sleep was significantly lower than during waking. But in OSAS, there was no difference between during waking and sleep. Conclusion : These results suggested that recurrent hypoxia and arousals from sleep in patients with obstructive sleep apnea syndrome may increase sympathetic nervous system activity, and recurrent hypoxia and increased sympathetic nervous system activity could contribute to the development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac function.

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Excavation of Kim Jeong-gi and Korean Archeology (창산 김정기의 유적조사와 한국고고학)

  • Lee, Ju-heun
    • Korean Journal of Heritage: History & Science
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    • v.50 no.4
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    • pp.4-19
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    • 2017
  • Kim Jeong-gi (pen-name: Changsan, Mar. 31, 1930 - Aug. 26, 2015) made a major breakthrough in the history of cultural property excavation in Korea: In 1959, he began to develop an interest in cultural heritage after starting work as an employee of the National Museum of Korea. For about thirty years until he retired from the National Research Institute of Cultural Heritage in 1987, he devoted his life to the excavation of our country's historical relics and artifacts and compiled countless data about them. He continued striving to identify the unique value and meaning of our cultural heritage in universities and excavation organizations until he passed away in 2015. Changsan spearheaded all of Korea's monumental archeological excavations and research. He is widely known at home and abroad as a scholar of Korean archeology, particularly in the early years of its existence as an academic discipline. As such, he has had a considerable influence on the development of Korean archeology. Although his multiple activities and roles are meaningful in terms of the country's archaeological history, there are limits to his contributions nevertheless. The Deoksugung Palace period (1955-1972), when the National Museum of Korea was situated in Deoksugung Palace, is considered to be a time of great significance for Korean archeology, as relics with diverse characteristics were researched during this period. Changsan actively participated in archeological surveys of prehistoric shell mounds and dwellings, conducted surveys of historical relics, measured many historical sites, and took charge of photographing and drawing such relics. He put to good use all the excavation techniques that he had learned in Japan, while his countrywide archaeological surveys are highly regarded in terms of academic history as well. What particularly sets his perspectives apart in archaeological terms is the fact that he raised the possibility of underwater tombs in ancient times, and also coined the term "Haemi Culture" as part of a theory of local culture aimed at furthering understanding of Bronze Age cultures in Korea. His input was simply breathtaking. In 1969, the National Research Institute of Cultural Heritage (NRICH) was founded and Changsan was appointed as its head. Despite the many difficulties he faced in running the institute with limited financial and human resources, he gave everything he had to research and field studies of the brilliant cultural heritages that Korea has preserved for so long. Changsan succeeded in restoring Bulguksa Temple, and followed this up with the successful excavation of the Cheonmachong Tomb and the Hwangnamdaechong Tomb in Gyeongju. He then explored the Hwangnyongsa Temple site, Bunhwangsa Temple, and the Mireuksa Temple site in order to systematically evaluate the Buddhist culture and structures of the Three Kingdoms Period. We can safely say that the large excavation projects that he organized and carried out at that time not only laid the foundations for Korean archeology but also made significant contributions to studies in related fields. Above all, in terms of the developmental process of Korean archeology, the achievements he generated with his exceptional passion during the period are almost too numerous to mention, but they include his systematization of various excavation methods, cultivation of archaeologists, popularization of archeological excavations, formalization of survey records, and promotion of data disclosure. On the other hand, although this "Excavation King" devoted himself to excavations, kept precise records, and paid keen attention to every detail, he failed to overcome the limitations of his era in the process of defining the nature of cultural remains and interpreting historical sites and structures. Despite his many roles in Korean archeology, the fact that he left behind a controversy over the identity of the occupant of the Hwangnamdaechong Tomb remains a sore spot in his otherwise perfect reputation.