• 천문학회보
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• 제44권2호
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• pp.35.1-35.1
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• 2019

One day, a galaxy study suddenly came to me and became a friend of 40 years. The study of galaxies, which began with surface photometry of nearby galaxies, ended up in galaxy morphology through chemical and dynamical evolution of galaxies. All that deviated from the study of galaxies was the study of the open clusters. So it seems to me that I devoted my entire life to the study of galaxies. The most memorable one is the observation at Sobaeksan Observatory. Even though the heavy snow fell, I climbed Sobaeksan to meet galaxies. Galaxies observed at Kiso Observatory, DAO, and BOAO are now beyond memory, but I still enjoy seeing them. There are many memories, but the biggest pleasure I've had in my galaxy studies is when I've encountered the galactic conformity between host and its satellite galaxies. Eureka! Now the night sky is changing from the object of study to the object of awe. I will share this joy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.814-817
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• 2003

Assuming that life of urban transit signalling is about 20 years with the flow of technology development, Seoul urban transit will be required to prepare for improvement soon. The highly developed countries preceding several levels rather than Korea are faced with commercial service which uses RF, ATC and ATO in Train Control System. European highly developed countries in the field of railroad have been progressing standardization and technology development of signalling associated with related manufacturers for direct operation between nations. For that, a effective train control system with radio beyond control levels by the existing wayside-onboard communication is in a developed and used stage. The systems which advanced countries have been progressing seem to be applied to domestic within 5 years from now. At present, there are no countries using CBTC for service throughout the world. So, this is investigated to focus on the routes ready to be installed with completed CBTC and trying to introduce the technology. Especially, considerations for economic aspect are mainly reviewed about controlling ability of headway, flexibility, extension aspect and construction cost on the basis of paper examined in NYCT.

• Communications for Statistical Applications and Methods
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• 제22권6호
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• pp.543-556
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• 2015

We present a survey of contributions that defined the nature and extent of robust statistics for the last 50 years. From the pioneering work of Tukey, Huber, and Hampel that focused on robust location parameter estimation, we presented various generalizations of these estimation procedures that cover a wide variety of models and data analysis methods. Among these extensions, we present linear models, clustered and dependent observations, times series data, binary and discrete data, models for spatial data, nonparametric methods, and forward search methods for outliers. We also present the current interest in robust statistics and conclude with suggestions on the possible future direction of this area for statistical science.

• Annals of Surgical Treatment and Research
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• 제95권6호
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• pp.324-332
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• 2018

Purpose: We present our experience involving the management of this disease, identifying prognostic factors affecting treatment outcomes. Methods: The patients treated for Fournier gangrene at our institution were retrospectively reviewed. Data collected included demographics, extent of soft tissue necrosis, predisposing factors, etiological factors, laboratory values, and treatment outcomes. The severity index and score were calculated. Multivariate regression analysis was used to determine the association between potential predictors and clinical outcomes. Results: A total of 41 patients (male:female = 33:8) were studied. The mean age was 54.4 years (range, 24-79 years). The most common predisposing factor was diabetes mellitus (n = 19, 46.3%). Sixteen patients (39.0%) were current smokers. Seven patients had chronic kidney disease. The most frequent etiology was urogenital lesion (41.5%). The mortality rate was 22.0% (n = 9). Multivariate regression analyses showed that extension of necrosis beyond perineal/inguinal area and pre-existing chronic kidney disease were significant and independent predictors of mortality. Extension of necrosis beyond perineal/inguinal area was a significant predictor of increased duration in the intensive care unit and hospital stay. In addition, pre-existing chronic kidney disease was a significant predictor of flap reconstruction in the wound. Conclusion: Fournier gangrene with extensive soft tissue necrosis and pre-existing chronic kidney disease was associated with poor prognosis and complexity of patient management. Early recognition of dissemination and premorbid renal function is essential to reduce mortality and establish a management plan for this disease.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제50권2호
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• pp.70-79
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• 2024

Objectives: The surgical guide is a static computer-assisted device used for implant surgery planning and guidance. By taking an impression and referring to the patients' three-dimensional computed tomography scan of the desired implant site, a surgical guide can be created. During surgery, the surgical guide aids in achieving the designed implant placement position and direction. We examined and evaluated the long-term clinical outcomes of implant surgery using surgical guides. Materials and Methods: This study investigated a total of 15 patients with 32 implants that were placed using surgical guides from 2009 to 2011 with a mean follow-up period extended beyond 10 years. Patient demographics and implant survival rates were recorded. We analyzed marginal bone loss (MBL) by assessing the radiographs acquired at installation, three months after installation, and one month, one, two, and five years after prosthesis delivery. Results: The mean patient age was 57.33 years at implant placement. Of the 32 implants, five implants were placed in the anterior region and 27 implants were in the posterior region. Six implants failed and three of them were replaced, resulting in an 81.25% survival rate. The mean follow-up period was 10 years and nine months. Mean MBL compared to post-installation was significantly higher than at three months after installation, and one month, one, two, and five years after prosthesis delivery. Mean MBL at three months after installation, and one month, one year, and two years were significantly higher compared to the previous visit (P<0.05). However, MBL at five years after prosthesis delivery did not differ significantly compared to at two years. Conclusion: In this study, implant rehabilitation assisted by surgical guides exhibited favorable survival rates. With the limitation of the sample amount in this study, further research and more samples are required to evaluate the long-term clinical effectiveness of surgical guides.

• Asian-Australasian Journal of Animal Sciences
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• 제14권9호
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• pp.1326-1330
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• 2001

This study analyzed the lowest production cost and the greatest profit to be obtained from marketing hogs to determine the optimal operation scale for family-owned farrow-to-finish farms. Data were collected from 39 farrow-to-finish farms with 500 to 5,000 inventories for two consecutive years, and treated with GLM and quadratic regression models using the REG procedure. Analysis results indicated that farms capable of marketing 2,933 and 3,286 hogs annually had the lowest production cost and the greatest profit, respectively. Further analysis attributed the lowest production cost or the highest return in farms with an optimal scale of 3,000 to a higher survival rate of the herd, as well as lower expenses in veterinary medicine, labor, utilities and fuel, transportation, and depreciation. A similar feed conversion efficiency was observed for all the farms studied. Obviously, the cost efficiencies were associated with the economy of the operation scale of hog production until it reached 3,000 hogs marketed annually for a family-run unit. Beyond the optimal scale of 3,000 hogs, good stockmanship was more difficult to maintain and the herd management deteriorated as increasing mortality confirms. It is conclude that, unless advanced management is applied, the operation scale should not expand beyond 3,000 hogs.

• 한국중재학회지:중재연구
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• 제8권1호
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• pp.269-291
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• 1998

Change of circumstances subsequent to formation of international business contract raises two issues on both parties' obligation to perform business transaction concerned. One is impossibility of performance due to events beyond control of parties and the other is adaption of contract. In Anglo-American Law such an impossibility of performance is provided by the doctrine of Frustration and the doctrine of Practicability(UCC 2-615). In practice a "force majeure" clause should be included in contract defining the parties' mutual rights and duties if certain events beyond their control occur to safeguard themselves against possible impossibility. On the other hand the tendency of international trade is that alongside sales contracts, there are contract for supplies, for furnishing raw materials, for building industrial complexes, and transferring technology. One characteristic of these agreements is their duration. For in order to carry out these agreements, it is necessary to complete a series of closely interrelated operations which, in the normal course of events, take place over a number of years. It is often difficult for the parties, when finalizing their contract, to have a full grasp of all of the factors governing their relations. With a view to resolving difficulties such as compromise the continuous performance of a contract, parties may insert a regulatory clause in their contract providing for intervention by a third person after stating in specific and detailed fashion the circumstances in which their contract may be adapted.

• International Journal of Internet, Broadcasting and Communication
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• 제12권1호
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• pp.7-13
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• 2020

We describes V2X technology, a connectivity-based recognition technology that is attracting attention as a key technology for implementing autonomous driving technology, and autonomous communication modules that implement ADAS technology, a sensor-based recognition technology. It also explains the trends in V2X technology standardization centered on IEEE 802.11p, which is a WAVE technology standard based on Wi-Fi/DSRC. Finally, we will discuss the market growth trend of V2X communication modules in the United States, the leading V2X technology module, and the development of technology development trends of major domestic and international companies that are leading the global technology market related to V2X communication modules. V2X and ADAS technologies will be the biggest influence on automotive purchasing decisions. In recent years, V2I mandates have been promoted beyond V2V, mainly in developed countries such as the United States. The related industry needs to focus on the development of information transmission network technology that can support high frequency high efficiency(transmission rate) and sophisticated positioning accuracy beyond conventional vehicle communication.

• Asian Pacific Journal of Cancer Prevention
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• 제16권13호
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• pp.5433-5438
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• 2015

Background: Systemic chemotherapy for patients with metastatic gastric cancer (MGC) is generally palliative, although some patients experience long-term survival after treatment. Thus, we identified clinical characteristics that are associated with long-term survival of patients with MGC after palliative chemotherapy. Materials and Methods: We retrospectively reviewed 514 MGC patients who received systemic chemotherapy at our institution from 2001 to 2008. To identify clinical predictors of survival beyond 2 years, multivariate logistic regression analyses were performed, and 5-year survival rates were estimated among MGC patients following chemotherapy. Results: Among 514 patients, 96 (19%) and 16 (3%) survived beyond 2 and 5 years, respectively, and performance status of 0 or 1 (odds ratio [OR]=3.39; p=0.01), previous gastrectomy (OR=1.86; p=0.01), single metastatic site (OR=1.80; p=0.03), and normal alkaline phosphatase levels (OR=2.81; p<0.01) were identified as independent predictors of long-term survival. Of the 16 5-year survivors, six were alive at the end of the study and showed no evidence of disease despite cessation of chemotherapy. Conclusions: The present data demonstrate distinct clinical characteristics that are associated with long-term survival of MGC patients, and indicated that palliative chemotherapy can be curative in highly selected patients.

• 한국압력기기공학회 논문집
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• 제15권2호
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• pp.64-70
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• 2019

In recent years, attention has been paid to the integrity of steam generator (SG) tubes due to severe accident and beyond design basis accident conditions. In these transient conditions, steam generator tubes may be damaged by high temperature and pressure, which might result in a risk of fission products being released to the environment due to the failure. Alloy 690 which has increased the Cr content has been replaced for the SG tube due to its high corrosion resistance against stress corrosion cracking (SCC). However, there is lack of research on the high temperature creep rupture and life prediction model of Alloy 690. In this study, creep test was performed to estimate the high temperature creep rupture life of Alloy 690 using tube specimens. Based on manufacturer's creep data and creep test results performed in this study, creep life prediction was carried out using the Larson-Miller (LM) Parameter, Orr-Sherby-Dorn (OSD) parameter, Manson-Haford (MH) parameter, and Wilshire's approach. And a hyperbolic sine (sinh) function to determine master curves in LM, OSD and MH parameter methods was used for improving the creep life estimation of Alloy 690 material.