• Journal of Chest Surgery
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• v.57 no.5
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• pp.484-489
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• 2024

Background: Catamenial pneumothorax (CP) is a rare form of spontaneous pneumothorax that is linked to endometriosis; thus, it predominantly manifests in women of reproductive age. Considerable research has explored the potential benefits of postoperative hormone therapy following various surgical interventions. This study was performed to examine the clinical implications of postoperative hormone treatment in patients with CP. Methods: The study included patients who underwent surgical intervention for CP between November 2009 and February 2023. These procedures included wedge resection, diaphragm resection, and total pleural coverage. Recurrence-free survival was analyzed using the Kaplan-Meier log-rank test to assess the impact of hormone therapy. Additionally, Cox proportional hazards analysis was employed to identify risk factors associated with postoperative CP recurrence. Results: The study included 41 patients, with a median age of 38.4 years. Among them, 27 individuals received hormone therapy, 8 of whom experienced recurrence during a median follow-up period of 1 year. Patients who received hormone therapy exhibited a lower rate of recurrence than those who did not; however, the difference was not statistically significant, likely due to the small sample size. Side effects of hormone therapy included depression (6.8%), excessive sweating (3.4%), and headache (3.4%). In the analysis of risk factors for postoperative recurrence, diaphragm resection emerged as a protective factor (hazard ratio, 0.16; 95% confidence interval, 0.03-0.77; p=0.022). Conclusion: Hormone treatment combined with surgery did not significantly impact recurrence in patients with CP. The application of diaphragm resection was the sole factor that displayed significance in preventing CP recurrence.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.707-710
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• 2011

System safety is defined as the state where the hazard risks due to internal system, interface, operation and maintenance are controlled as acceptable levels. It is represented and evaluated either with the risk level of each risk factor with the consideration of operation environments or with Safety Integrity Level (SIL) which is the system functional safety without considering application environments. The assessment results are issued in forms of certificates and they are reused in many cases. However, the conditions and restrictions for different application environments vary in each case, therefore, additional evaluation on the preconditions of assessment in comparison with the actual application environment must be carried out. For the area of train control, TR 50506-1 has been established based on the IEC 62425 (international standard for safety of train control system by RSSB) and EN 50129 (Europe standard) for the further assessment. In this paper, the analysis on TR 5056-1 has been conducted in depth. The purpose of the study is to determine the requirements for inter-acceptability including scope, procedures, principles, examination and suitability. The results can be utilized for the system safety maintenance when new devices or components are introduced in conventional systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.547-566
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• 2014

This study investigates the decisive factors affecting the survival or collapse of cable networks in the Korean paid broadcasting market from 1993 to 2010. The effects of performance variables discussed in previous studies were verified through survival analyses. According to the results, the most influential factors in the survival of cable networks were horizontal integration (MPP), channel genre, the scheduling of HDTV content, and the proportion of access program scheduling. These findings imply that the differentiation strategy of content suppliers is the most decisive factor among all business performance-related factors. Specifically, the content supply power and strategy of the program provider (PP) have the greatest influence on cable network viability. The present study is meaningful as the first attempt to establish the performance of PPs in Korean pay broadcasting markets through the viewpoint of organizational mortality. Accordingly, the present study can supplement the results of cross-sectional studies conducted with smaller samples.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3831-3836
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• 2013

Background: S100A14 has recently been implicated in the progress of several types of cancers. This study aimed to investigate the clinical significance and possible mechanisms of action of S100A14 in the invasion and metastasis of hepatocellular carcinoma (HCC). Methods: S100A14 expression in HCC was detected at mRNA and protein levels and its prognostic significance was assessed. Functional roles of S100A14 in HCC were investigated using MTT, BrdU, wound healing, transwell invasion assay and HCC metastatic mouse model. Results: S100A14 was significantly elevated in HCC tissues, correlated with multiple tumor nodes, high Edmondson-Steiner grade and vascular invasion. Multivariate Cox analysis showed that the S100A14 expression level was a significant and independent prognostic factor for overall survival (OS) of HCC patients (hazard ratio=1.98, 95% confidence interval=1.14-3.46, P=0.013). S100A14 promoted cell proliferation, invasion and metastasis of HCC in vitro and in vivo. Conclusion: These results suggest S100A14 is a novel prognostic marker and therapeutic target for HCC.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.45-52
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• 2006

The AITs(autoignition temperatures) describe the minimum temperature to which a substance must be heated, without the application of a flame or spark, which will cause that substance to ignite. The AITs are often used as a factor in determining the upper temperature limit for processing operations and conditions for handling, storage and transportation, and in determining potential fire hazard from accidental contact with hot surfaces. The measurement AITs are dependent upon many factors, namely initial temperature, pressure, volume, fuel/air stoichiometry, catalyst material, concentration of vapor, time lag. Therefore, the AITs reported by different ignition conditions are sometimes significantly different. This study measured the AITs of benzene, toluene and xylene isomers from time lag using AS1M E659-78 apparatus. The experimental ignition delay times were a good agreement with the calculated ignition delay times by the proposed equations wtih a few A.A.D.(average absolute deviation). Also The experimental AITs of benzene, toluene, o-xylene, m-xylene and p-xylene were $583^{\circ}C,\;547^{\circ}C,\;480^{\circ}C,\;587^{\circ}C,\;and\;557^{\circ}C$, respectively.

• Toxicological Research
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• v.17
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• pp.41-45
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• 2001

The methods used for risk assessment from exposure to chemicals are well established. in most cases where toxicity other than carcinogenesis is being considered, the standard method relies on establishing the No Observed Adverse Effect Level (NOAEL) in the most sensitive animal toxicity study and using an appropriate safety factor (SF) to determine the exposure which would be associated with an acceptable risk. For carcinogens a different approach is used because it has been argued there is no threshold of effect. Thus mathematical equations are used to extrapolate from the high doses used in ani-mal experiments. These methods have been strongly criticised in recent years on several grounds. The most cogent criticisms are a) the equations are not based on a thorough understanding of the mechanisms of carcinogenesis and b) the outcome of a risk assessment based on such models varies more as a consequence of changes to the assumptions and equation used than it does from the data derived from carcinogenicity experiments. Other criticisms include the absence of any measure of the variance on the risk assessment and the selection of default values that are very conservative. Recent advances in the application of risk assessment emphasise that measures of both the exposure and the hazard should be considered as a distribution of values. The outcome of such a risk assessment provides an estimate of the distribution of the risks.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.12-19
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• 2011

Drawing on its extensive experience with natural disasters, Japan has been dispatching Japan Disaster Relief (JDR) team to disaster-stricken countries to provide specialist assistance in rescue and medical operations. The JDR team has assisted in the wake of disasters including the 2004 Indian Ocean Earthquake and the 2008 Sichuan Earthquake in China. Information about the affected area is essential for a rapid disaster response. However, it can be difficult to gather information on damages in the immediate post-disaster period. To help overcome this problem, we have built on an Earthquake Damage Estimation System. This system makes it possible to produce distributions of the earthquake's seismic intensity and structural damage based on pre-calculated data such as landform and site amplification factors for Peak Ground Velocity, which are estimated from a Digital Elevation Model, as well as population distribution. The estimation result can be shared with the JDR team and with other international organizations through communications satellite or the Internet, enabling more effective rapid relief operations.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.91-91
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• 2011

The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

• Journal of the Korean Society of Safety
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• v.29 no.5
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• pp.88-96
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• 2014

Each year, it seems inevitable that major accidents will occur on construction sites. Industrial accidents, sometimes involving foreign laborers, have been constantly increasing. Construction laborers have higher hazard rates and higher work intensity than other industries, which means that they experience more job stress, as a result of the subcontracting structure. Therefore, this study performed an influence factor analysis on job stress and its relevance to industrial accidents involving Korean and foreign construction laborers, and proposed its effectiveness with the job stress and construction accident management measures based on the results of those. A questionnaire to measure job stress was performed targeting Korean and foreign laborers, and the results were analyzed. The results of this study can be utilized as important reference materials in efforts to reduce the job stress of foreign laborers on construction sites, and can be expected to contribute to preventing construction accidents related to job stress in the future.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.1
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• pp.35-43
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• 1999

The purpose of this study is to derive the optimal methodology estimating the changes of fluvial hydraulic characteristics due to semi-covering work of urban stream. First, after collecting the data of the daily maximum rainfall of Chungju gaging station, the frequency analysis was carried out with frequency factor method, which includes normal, two-parameter and three-parameter lognormal, Gumbel-Chow, pearson type III, log-pearson type III distribution, and the goodness of fit test was executed by $x^2$-test and Kormogorov-Smimov test. Using the SCS method, the effective rainfall was estimated and the peak flow was calculated by the area-routing method. The HEC-2 model was applied to calculate water surface profiles for steady, gradually varied flow at Kyohyun river system in Chungju city. The model was applied to floodplain and riverbed management to evaluate flood way encroachments and to delineate flood hazard by riverside roadway construction. The model also was used to evaluate effects on water surface profiles of river improvement and levees as well as the presence of bridges or other hydraulic structures in the floodplain.