• Title/Summary/Keyword: cause analysis

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Redefinition of the Concept of Fishing Vessel and Legislation Adjustment (낚시어선 개념의 재정립과 법제 정비에 관한 연구)

  • Yeong-Tae Son
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.6
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    • pp.639-652
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    • 2023
  • The fundamental background behind the introduction of the fishing vessel system is to allow petty small fishers to engage in pure fishery business activities with fishing vessels during normal times and engage in fishing vessel business only during specific periods (closed fishing season, etc.) thereby granting a qualification as an auxiliary tool for the economic activities of petty small fishers. In addition, fishing boats are allowed to engage in excursion ship activities using fishing vessels registered under the Fishing Vessels Act, the form of fishing vessels should also have a general and universal structure that is practically easy to engage in fishing activities in the field in accordance with the relevant regulations. However, most fishing vessel proprietors are currently focusing only on increasing income, and rather than building fishing vessels in a reasonable form suitable for the original purpose of general fishing vessels, they prefer an abnormal hull form equivalent to expediency, that is biased hull structure biased toward the fishing vessel business. As a result, it is causing serious problems in safety management as well as conflict [damaging relative equity in government support measures (tax-free oil supply, etc.), and depletion of livelihood-type fish stocks] with fishing vessel forces who consider the fishing vessel business only to be a part of the side job among all fishery business activities. Meanwhile, the most fundamental cause of this problem is that the current Fishing Management and Promotion Act, limits the concept of fishing vessels to fishing vessels registered under the Fishing Vessels Act, and applies survey standards accordingly. Accordingly, in this study, through analysis of the distribution status of fishing vessels, structural characteristics, operation status of fishing vessels, and the government's fishing promotion policies, etc., the relevant laws (regulations) have been reorganized to suit the current reality of the concept of fishing vessels to separate the current fishing vessel from fishing vessels and operate it as a fishing-only vessel.

Test of Independence Between Variables to Estimate the Frequency of Damage in Heat Pipe (열수송관 파손빈도 추정을 위한 변수간 독립성 검정)

  • Myeongsik Kong;Jaemo Kang;Sungyeol Lee
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.12
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    • pp.61-67
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    • 2023
  • Heat pipes located underground in urban areas and operated under high temperature and pressure conditions can cause large-scale human and economic damage if damaged. In order to predict damage in advance, damage and construction information of heat pipe are analyzed to derive independent variables that have a correlation with frequency of damage, and a simple regression analysis modified model using each variable is applied to the field. However, as the correlation between independent variables applied to the model increases, the independence between variables is harmed and the reliability of the model decreases. In this study, the independence of the pipe diameter, burial depth, insulation level of monitoring system, and disconnection or short circuit of the detection line, which are judged to be interrelated, was tested to derive a method for combining variables and setting categories necessary to apply to the frequency of damage estimation model. For the test of independence, the continuous variables pipe diameter and burial depth were each converted into three categories, insulation level of monitoring system was converted into two categories, and the categorical variable disconnection or short circuit of the detection line status was kept as two categories. As a result of the test of independence, p-value between pipe diameter and burial depth, level of monitoring system and disconnection or short circuit of the detection line was lower than the significance level (α = 0.05), indicating a large correlation between them. Therefore, the pipe diameter and burial depth were combined into one variable, and the categories of the combined variable were set to 9 considering the previously set categories. The insulation level of monitoring system and the disconnection or short circuit of the detection line were also combined into one variable. Since the insulation level is unreliable when the detection line status is disconnection or short circuit, the categories of the combined variable were set to 3.

A Study on the Priority of RoboAdvisor Selection Factors: From the Perspective of Analyzing Differences between Users and Providers Using AHP (로보어드바이저 선정요인의 우선순위에 관한 연구: AHP를 이용한 사용자와 제공자의 차이분석 관점으로)

  • Young Woong Woo;Jae In Oh;Yun Hi Chang
    • Information Systems Review
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    • v.25 no.2
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    • pp.145-162
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    • 2023
  • Asset management is a complex and difficult field that requires insight into numerous variables and even human psychology. Thus, it has traditionally been the domain of professionals, and these services have been expensive to obtain. Changes are taking place in these markets, and the driving force is the digital revolution, so-called the fourth industrial revolution. Among them, the Robo-Advisor service using artificial intelligence technology is the highlight. The reason is that it is possible to popularize investment advisory services with convenient accessibility and low cost. This study aims to clarify what factors are critically important when selecting robo-advisors for service users and providers in Korea, and what perception differences exist in the selection factors between user and provider groups. The framework of the study was based on the marketing mix 4C model, and the design and analysis of the model used Delphi survey and AHP. Through the study design, 4 main criteria and 15 sub-criteria were derived, and the findings of the study are as follows. First, the importance of the four main criteria was in the order of customer needs > customer convenience > customer cost > customer communication for both groups. Second, looking at the 15 sub-criteria, it was found that investment purpose coverage, investment propensity coverage, fee level and accessibility factors were the most important. Third, when comparing between groups, the user group found that the fee level and accessibility factors were the most important, and the provider group recognized the investment purpose coverage and investment propensity coverage factors as important. This study derived useful implications in practice. First, when designing for the spread of the robo-advisor service, the basis for constructing a user-oriented system was prepared by considering the priority of importance according to the weight difference between the four main criteria and the 15 sub-criteria. In addition, the difference in priority of each sub-criteria shown in the group comparison and the cause of the sub-criteria with large weight differences were identified. In addition, it was suggested that it is very important to form a consensus to resolve the difference in perception of factors between those in charge of strategy and marketing and system development within the provider group. Academically, it is meaningful in that it is an early study that presented various perspectives and perspectives by deriving a number of robo-advisor selection factors. Through the findings of this study, it is expected that a successful user-oriented robo-advisor system can be built and spread in Korea to help users.

Paprika Damping-off Outbreak Caused by Fusarium oxysporum Contaminated Seeds in Cheorwon Province in 2023 (2023 파프리카 종자의 Fusarium oxysporum 오염에 의한 철원지역 파프리카 모잘록병 대발생)

  • Miah Bae;Namsuk Kim;Sang Woo Kim;Sangyeon Ju;Byungyeon Kim;Soo Man Hwang;MeeKyoung Kim;Mi-Ri Park
    • Research in Plant Disease
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    • v.30 no.1
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    • pp.26-33
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    • 2024
  • In 2023, symptoms like damping-off disease were observed in 74 paprika growing in greenhouses in Cheorwon-gun, Gangwon-do, Korea. In this study, we tried to find the cause of the damping-off disease outbreak. We collected symptomatic seedlings and observed the typical crescent-shaped conidia of Fusarium oxysporum by microscope. To confirm the presence of F. oxysporum in the samples, polymerase chain reaction was performed using primers specific for F. oxysporum; the resulting sequence showed 99.11% identity with F. oxysporum. To confirm the pathogenicity of the F. oxysporum (CW) isolated from the samples, healthy paprika plants were inoculated with F. oxysporum CW and damping-off symptoms were observed 2 weeks later. To investigate whether the damping-off disease outbreak in Cheorwon-gun was caused by F. oxysporum-contaminated seeds, 100 paprika seeds were disinfected and placed in Murashige and Skoog medium. Typical pink F. oxysporum hyphae were found only in control non-disinfected seeds. An 18S rRNA-based and a TEF genebased phylogenetic analysis showed that the F. oxysporum CW isolate was not grouped with a F. oxysporum isolate reported from Cheorwon-gun in 2019. This study is the first report that an outbreak of damping-off disease in paprika in Cheorwon-gun, Gangwon-do, Korea, was caused by contamination of F. oxysporum seeds.

COMPARISON OF POLYMERIZATION SHRINKAGE AND STRAIN STRESS OF SEVERAL COMPOSITE RESINS USING STRAIN GUAGE (스트레인 게이지를 이용한 수종의 복합레진의 중합수축 및 수축응력의 비교)

  • Kim, Young-Kwang;Yoo, Seung-Hoon;Kim, Jong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.3
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    • pp.516-526
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    • 2004
  • Polymerization shrinkage of photoinitiation type composite resin cause several clinical problems. The purpose of this study was to evaluate the shrinkage strain stress, linear polymerization shrinkage, compressive strength and microhardness of recently developed composite resins. The composite resins were divided into four groups according to the contents of matrix and filler type. Group I : $Denfil^{TM}$(Vericom, Korea) with conventional matrix, Group II : $Charmfil^{(R)}$(Dentkist, Korea) with microfiller and nanofller mixture, Group III : $Filtek^{TM}$ Z250(3M-ESPE, USA) TEGDMA replaced by UDMA and Bis-EMA(6) in the matrix, and Group IV : $Filtek^{TM}$ Supreme(3M-ESPE, USA) using pure nanofiller. Preparation of acrylic molds were followed by filling and curing with light gun. Strain gauges were attached to each sample and the leads were connected to a strainmeter. With strainmeter shrinkage strain stress and linear polymerization shrinkage was measured for 10 minutes. The data detected at 1 minute and 10 minutes were analysed statistically with ONE-way ANOVA test. To evaluate the mechanical properties of tested materials, compressive hardness test and microhardness test were also rendered. The results can be summarized as follows : 1. Filling materials in acrylic molds showed initial temporary expansion in the early phase of polymerization. This was followed by contraction with the rapid increase in strain stress during the first 1 minute and gradually decreased during post-gel shrinkage phase. After 1 minute, there's no statistical differences of strain stress between groups. The highest strain stress was found in group IV and followed by group III, I, II at 10 minutes-measurement(p>.05). In regression analysis of strain stress, group III showed minimal inclination and followed by group II, I, IV during 1 minute. 2. In linear polymerization shrinkage test, the composite resins in every group showed initial increase of shrinkage velocity during the first 1 minute, followed by gradually decrease of shrinkage velocity. After 1 minute, group IV and group III showed statistical difference(p<.05). After 10 minutes, there were statistical differences between group IV and group I, III(p<.05) and between group II and group III(p<.05). In regression analysis of linear polymerization shrinkage, group II showed minimal inclination and followed by group IV, III, I during 1 minute. 3. In compressive strength test, group III showed the highest strength and followed by group II, IV, I. There were statistical differences between group III and group IV, I(p<.05). 4. In microhardness test, upper surfaces showed higher value than lower surfaces in every group(p<.05).

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A New Exploratory Research on Franchisor's Provision of Exclusive Territories (가맹본부의 배타적 영업지역보호에 대한 탐색적 연구)

  • Lim, Young-Kyun;Lee, Su-Dong;Kim, Ju-Young
    • Journal of Distribution Research
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    • v.17 no.1
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    • pp.37-63
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    • 2012
  • In franchise business, exclusive sales territory (sometimes EST in table) protection is a very important issue from an economic, social and political point of view. It affects the growth and survival of both franchisor and franchisee and often raises issues of social and political conflicts. When franchisee is not familiar with related laws and regulations, franchisor has high chance to utilize it. Exclusive sales territory protection by the manufacturer and distributors (wholesalers or retailers) means sales area restriction by which only certain distributors have right to sell products or services. The distributor, who has been granted exclusive sales territories, can protect its own territory, whereas he may be prohibited from entering in other regions. Even though exclusive sales territory is a quite critical problem in franchise business, there is not much rigorous research about the reason, results, evaluation, and future direction based on empirical data. This paper tries to address this problem not only from logical and nomological validity, but from empirical validation. While we purse an empirical analysis, we take into account the difficulties of real data collection and statistical analysis techniques. We use a set of disclosure document data collected by Korea Fair Trade Commission, instead of conventional survey method which is usually criticized for its measurement error. Existing theories about exclusive sales territory can be summarized into two groups as shown in the table below. The first one is about the effectiveness of exclusive sales territory from both franchisor and franchisee point of view. In fact, output of exclusive sales territory can be positive for franchisors but negative for franchisees. Also, it can be positive in terms of sales but negative in terms of profit. Therefore, variables and viewpoints should be set properly. The other one is about the motive or reason why exclusive sales territory is protected. The reasons can be classified into four groups - industry characteristics, franchise systems characteristics, capability to maintain exclusive sales territory, and strategic decision. Within four groups of reasons, there are more specific variables and theories as below. Based on these theories, we develop nine hypotheses which are briefly shown in the last table below with the results. In order to validate the hypothesis, data is collected from government (FTC) homepage which is open source. The sample consists of 1,896 franchisors and it contains about three year operation data, from 2006 to 2008. Within the samples, 627 have exclusive sales territory protection policy and the one with exclusive sales territory policy is not evenly distributed over 19 representative industries. Additional data are also collected from another government agency homepage, like Statistics Korea. Also, we combine data from various secondary sources to create meaningful variables as shown in the table below. All variables are dichotomized by mean or median split if they are not inherently dichotomized by its definition, since each hypothesis is composed by multiple variables and there is no solid statistical technique to incorporate all these conditions to test the hypotheses. This paper uses a simple chi-square test because hypotheses and theories are built upon quite specific conditions such as industry type, economic condition, company history and various strategic purposes. It is almost impossible to find all those samples to satisfy them and it can't be manipulated in experimental settings. However, more advanced statistical techniques are very good on clean data without exogenous variables, but not good with real complex data. The chi-square test is applied in a way that samples are grouped into four with two criteria, whether they use exclusive sales territory protection or not, and whether they satisfy conditions of each hypothesis. So the proportion of sample franchisors which satisfy conditions and protect exclusive sales territory, does significantly exceed the proportion of samples that satisfy condition and do not protect. In fact, chi-square test is equivalent with the Poisson regression which allows more flexible application. As results, only three hypotheses are accepted. When attitude toward the risk is high so loyalty fee is determined according to sales performance, EST protection makes poor results as expected. And when franchisor protects EST in order to recruit franchisee easily, EST protection makes better results. Also, when EST protection is to improve the efficiency of franchise system as a whole, it shows better performances. High efficiency is achieved as EST prohibits the free riding of franchisee who exploits other's marketing efforts, and it encourages proper investments and distributes franchisee into multiple regions evenly. Other hypotheses are not supported in the results of significance testing. Exclusive sales territory should be protected from proper motives and administered for mutual benefits. Legal restrictions driven by the government agency like FTC could be misused and cause mis-understandings. So there need more careful monitoring on real practices and more rigorous studies by both academicians and practitioners.

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Corporate Governance and Managerial Performance in Public Enterprises: Focusing on CEOs and Internal Auditors (공기업의 지배구조와 경영성과: CEO와 내부감사인을 중심으로)

  • Yu, Seung-Won
    • KDI Journal of Economic Policy
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    • v.31 no.1
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    • pp.71-103
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    • 2009
  • Considering the expenditure size of public institutions centering on public enterprises, about 28% of Korea's GDP in 2007, public institutions have significant influence on the Korean economy. However, still in the new government, there are voices of criticism about the need of constant reform on public enterprises due to their irresponsible management impeding national competitiveness. Especially, political controversy over appointment of executives such as CEOs of public enterprises has caused the distrust of the people. As one of various reform measures for public enterprises, this study analyzes the effect of internal governance structure of public enterprises on their managerial performance, since, regardless of privatization of public enterprises, improving the governance structure of public enterprises is a matter of great importance. There are only a few prior researches focusing on the governance structure and managerial performance of public enterprises compared to those of private enterprises. Most of prior researches studied the relationship between parachuting employment of CEO and managerial performance, and concluded that parachuting produces negative effect on managerial performance. However, different from the results of such researches, recent studies suggest that there is no relationship between employment type of CEOs and managerial performance in public enterprises. This study is distinguished from prior researches in view of following. First, prior researches focused on the relationship between employment type of public enterprises' CEOs and managerial performance. However, in addition to this, this study analyzes the relationship of internal auditors and managerial performance. Second, unlike prior researches studying the relationship between employment type of public corporations' CEOs and managerial performance with an emphasis on parachuting employment, this study researches impact of employment type as well as expertise of CEOs and internal auditors on managerial performance. Third, prior researchers mainly used non-financial indicators from various samples. However, this study eliminated subjectivity of researchers by analyzing public enterprises designated by the government and their financial statements, which were externally audited and inspected. In this study, regression analysis is applied in analyzing the relationship of independence and expertise of public enterprises' CEOs and internal auditors and managerial performance in the same year. Financial information from 2003 to 2007 of 24 public enterprises, which are designated by the government, and their personnel information from the board of directors are used as samples. Independence of CEOs is identified by dividing CEOs into persons from the same public enterprise and persons from other organization, and independence of internal auditors is determined by classifying them into two groups, people from academic field, economic world, and civic groups, and people from political community, government ministries, and military. Also, expertise of CEOs and internal auditors is divided into business expertise and financial expertise. As control variables, this study applied foundation year, asset size, government subsidies as a proportion to corporate earnings, and dummy variables by year. Analysis showed that there is significantly positive relationship between independence and financial expertise of internal auditors and managerial performance. In addition, although business expertise and financial expertise of CEOs were not statistically significant, they have positive relationship with managerial performance. However, unlike a general idea, independence of CEOs is not statistically significant, but it is negatively related to managerial performance. Contrary to general concerns, it seems that the impact of independence of public enterprises' CEOs on managerial performance has slightly decreased. Instead, it explains that expertise of public enterprises' CEOs and internal auditors plays more important role in managerial performance rather than their independence. Meanwhile, there are limitations in this study as follows. First, in contrast to private enterprises, public enterprises simultaneously pursue publicness and entrepreneurship. However, this study focuses on entrepreneurship, excluding considerations on publicness of public enterprises. Second, public enterprises in this study are limited to those in the central government. Accordingly, it should be carefully considered when the result of this study is applied to public enterprises in local governments. Finally, this study excludes factors related to transparency and democracy issues which are raised in appointment process of executives of public enterprises, as it may cause the issue of subjectivity of researchers.

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Radiotherapy in Medically Inoperable Early Stage Non-small Cell Lung Cancer (내과적 문제로 수술이 불가능한 조기 비소세포성 폐암에서의 방사선치료)

  • Kim, Bo-Kyoung;Park, Charn-Il
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.257-264
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    • 2000
  • Purpose: For early stage non-small-cell lung cancer, surgical resection is the treatment of choice. But when the patients are not able to tolerate it because of medical problem and when refuse surgery, radiation therapy is considered an acceptable alternative. We report on the treatment results and the effect of achieving local control of primary tumors on survival end points, and analyze factors that may influence survival and local control. Materials and Method : We reviewed the medical records of 32 patients with medically inoperable non-small cell lung cancer treated at our institution from June, 1987 through June, 1997. All patients had a pathologic diagnosis of non-small cell lung cancer and were not candidate for surgical resection because of either patients refusal (4), old age (2), lung problem (21), chest wail invasion (3) and heart problems (3). In 8 patients, there were more than 2 problems. The median age of the patients was 68 years (ranging from 60 to 86 years). Histologic cell type included souamous (24), adenocarcinoma (6) and unclassiried squamous cell (2). The clinical stages of the patients were 71 in 5, 72 in 25, 73 in 2 patients. Initial tumor size was 3.0 cm in 11, between 3.0 cm and 5.0 cm in 13 and more than 5.0 cm in 8 patients. Ail patients had taken chest x-rays, chest CT, abdomen USG and bone scan. Radiotherapy was delivered using 6 MV or 10 MV linear accelerators. The doses of primary tumor were the ranging from 54.0 Gy to 68.8 Gy (median; 61.2 Gy). The duration of treatment was from 37 days through 64 days (median; 0.5 days) and there was no treatment interruption except 1 patient due to poor general status. In 12 patients, concomitant boost technique was used. There were no neoadjuvant or adjuvant treatments such as surgery or chemotherapy. The period of follow-up was ranging from 2 months through 93 months (median; 23 months). Survival was measured from the date radiation therapy was initiated. Results : The overall survival rate was 44.6$\%$ at 2 years and 24.5$\%$ at 5 years, with the median survival time of 23 months. of the 25 deaths, 7 patients died of intercurrent illness, and cause-specific survival rate was 61.0$\%$ at 2 years and 33.5$\%$ at 5 years. The disease-free survival rate was 38.9$\%$ at 2 years and 28.3$\%$ at 5 years. The local-relapse-free survival rate was 35.1$\%$, 28.1$\%$, respectively. On univariate analysis, tumor size was significant variable of overall survival (p=0.0015, 95$\%$ C.1.; 1.4814-5.2815), disease-free survival (P=0.0022, 95$\%$ C.1., 1.4707-5.7780) and local-relapse-free survival (p=0.0015, 95$\%$ C.1., 1.2910- 4.1197). 7 stage was significant variable of overall survival (p=0.0395, 95$\%$ C.1.; 1.1084-55.9112) and had borderline significance on disease-free survival (p=0.0649, 95$\%$ C.1.; 0.8888-50.7123) and local-relapse-free survival (p=0.0582, 95$\%$ C,1.; 0.9342-52.7755). On multivariate analysis, tumor size had borderline significance on overall survival (p=0.6919, 955 C.1., 0.9610-5.1277) and local-relapse-free survival ( p=0.0585, 95$\%$ C.1.; 0.9720-4.9657). Tumor size was also significant variable of disease-free survival (p=0.0317, 95% C.1.; 1.1028-8.4968). Conclusion : Radical radiotherapy is an effective treatment for small (71 or f3 cm) tumors and can be offered as alternative to surgery in elderly or infirmed patients. But when the size of tumor is larger than 5 cm, there were few long-term survivors treated with radiotherapy alone. The use of hypefractionated radiotherapy, endobronchial boost, radisensitizer and conformal or IMRT should be consider to improve the local control rate and disease-specific survival rate.

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Clinical Study of Pulmonary Tuberculosis for Admitted Patients at National Masan Tuberculosis Hospital (국립마산결핵병원에 입원한 환자에 대한 폐결핵의 임상적 동태에 관한 연구)

  • Park, Seung-Kyu;Choi, In-Hwan;Kim, Chul-Min;Kim, Cheon-Tae;Song, Sun-Dae
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.2
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    • pp.241-250
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    • 1997
  • Objective : Although the prevalence of pulmonary tuberculosis has decreased progressively after the national control program for tuberculosis began, nowadays the number of MDRTB is increasing seriously. MDRTB tends to be poor responsive to current antituberculosis regimens. It is mainly due to poor compliance, high rate of side reaction of secondary drugs, and limitation in number of available drugs. The purpose of present study is to evaluate the clinical features of pulmonary tuberculosis patients admitted in one national tuberculosis hospital and to expose the problems pertaining to current remedies, to increase the treatment efficacy for pulmonary tuberculosis including MDRTB in the end. Method : Retrospective analysis of 336 pulmonary tuberculosis patients admitted in National Masan Tuberculosis Hospital was done. Contents of analysis were patients profile, the first diagnosed time and medical institutes, family history, residence, previous treatment history, chief complaints at the time of admission, lesion site on chest X -ray film, combined deseases, side reaction to antibuberculosis drugs, used drugs before admission and the results of drug sensitivity test. Results : The ratio between male and female was 4 : 1. Age showed relatively even distribution from 3rd to 6 th decades. 64.6% of the patients was diagnosed at public health center. Weight loss was the most common complaint at admission. Bilateral lesions on chest X-ray films were 59.8%. 130patients had combined desease, of which DM was the most common(37.7%). 95patients had family history, of which parents were the most common(41.7%). According to the time of first diagnosis, 31 patients were diagnosed before 1980, and after then the number of patients was increased by degrees. Residence overwhelmed in pusan and gyung-nam province. 258 patients got previous treatment history, of which 112 patients(43.4%) had more than 3 times and only 133 patients(51.6%)got regular medication. 97 patients used more than other 3 drugs in addition to INH, EMB, RFP and PZA before admission. 154 patients were informed with the results of drug sensitivity test. of which 77 patients had resistance to more than 5 drugs. Gastrointestinal problem was the most common in side reaction to drugs. Conclusion : In the case of weight loss of unknown cause, tuberculosis should be suspected. In first treatment, sufficient and satisfactory explanation for tuberculosis is necessary and treatment period should not be stict to 6 month-short term therapy. In retreatment, new drugs should not be added to used drugs even though drug sensitivity results show sensitivity to some of them. Proper time for surgical intervention should not be delayed.

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The Usefulness of Noninvasive Positive Pressure Ventilation in Patients With Acute Respiratory Failure after Extubation (기관내 관 제거 후 발생한 급성 호흡부전에서 비침습적 양압 환기법의 유용성)

  • Na, Joo-Ock;Lim, Chae-Man;Shim, Tae-Sun;Park, Joo-Hun;Lee, Ki-Man;Lee, Sang-Do;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong;Koh, Youn-Suck
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.3
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    • pp.350-362
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    • 1999
  • Background: Acute Respiratory failure which is developed after extubation in the weaning process from mechanical ventilation is an important cause of weaning failure. Once it was developed, endotracheal reintubation has been done for respiratory support. Noninvasive Positive Pressure Ventilation (NIPPV) has been used in the management of acute or chronic respiratory failure, as an alternative to endotracheal intubation, using via nasal or facial mask. In this study, we evaluated the usefulness of NIPPV as an alternative method of reintubation in patients who developed acute respiratory failure after extubation. Method: We retrospectively analyzed thirty one patients(eighteen males and thirteen females, mean ages $63\pm13.2$ years) who were developed acute respiratory failure within forty eight hours after extubation, or were extubated unintentionally at medical intensive care unit(MICU) of Asan Medical Center. NIPPV was applied to the patients. Ventilatory mode of NIPPV, level of ventilatory support and inspiratory oxygen concentration were adjusted according to the patient condition and results of blood gas analysis by the attending doctors at MICU. NIPPV was completely weaned when the patients maintained stable clinical condition under 8 $cmH_2O$ of pressure support level. Weaning success was defined as maintenance of stable spontaneous breathing more than forty eight hours after discontinuation of NIPPV. Respiratory rate, heart rate, arterial blood gas analysis, level of pressure support, and level of PEEP were monitored just before extubation, at thirty minutes, six hours, twenty four hours after initiation of NIPPV. They were also measured at just before weaning from NIPPV in success group, and just before reintubation in failure group. Results: NIPPV was successfully applied to thirty-one patients of thirty-two trials and one patient could not tolerated NIPPV longer than thirty minutes. Endotracheal reintubation was successfully obviated in fourteen patients (45%) among them. There was no difference in age, sex, APACHE III score on admission at MICU, duration of intubation, interval from extubation to initiation of NIPPV, baseline heart rate, respiratory rate, arterial blood gas, and $PaO_2/FiO_2$ between the success and the failure group. Heart rate and respiration rate were significantly decreased with increase $SaO_2$ after thirty minutes of NIPPV in both groups(p<0.05). However, in the patients of failure group, heart rate and respiratory rate were increased again with decrease in $SaO_2$ leading to endotracheal reintubation. The success rate of NIPPV treatment was significantly higher in the patients with COPD compared to other diseases(62% vs 39%) (p=0.007). The causes of failure were deterioration of arterial blood gas without aggravation of underlying disease(n=9), aggravation of undelying disease(n=5), mask intolerance(n=2), and retained airway secretion(n=l). Conclusion: NIPPV would be a useful therapeutic alternative which can avoid reintubation in patient who developed acute respiratory failure after extubation.

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