• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.47-73
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• 2020

KTX rolling stocks are a system consisting of several machines, electrical devices, and components. The maintenance of the rolling stocks requires considerable expertise and experience of maintenance workers. In the event of a rolling stock failure, the knowledge and experience of the maintainer will result in a difference in the quality of the time and work to solve the problem. So, the resulting availability of the vehicle will vary. Although problem solving is generally based on fault manuals, experienced and skilled professionals can quickly diagnose and take actions by applying personal know-how. Since this knowledge exists in a tacit form, it is difficult to pass it on completely to a successor, and there have been studies that have developed a case-based rolling stock expert system to turn it into a data-driven one. Nonetheless, research on the most commonly used KTX rolling stock on the main-line or the development of a system that extracts text meanings and searches for similar cases is still lacking. Therefore, this study proposes an intelligence supporting system that provides an action guide for emerging failures by using the know-how of these rolling stocks maintenance experts as an example of problem solving. For this purpose, the case base was constructed by collecting the rolling stocks failure data generated from 2015 to 2017, and the integrated dictionary was constructed separately through the case base to include the essential terminology and failure codes in consideration of the specialty of the railway rolling stock sector. Based on a deployed case base, a new failure was retrieved from past cases and the top three most similar failure cases were extracted to propose the actual actions of these cases as a diagnostic guide. In this study, various dimensionality reduction measures were applied to calculate similarity by taking into account the meaningful relationship of failure details in order to compensate for the limitations of the method of searching cases by keyword matching in rolling stock failure expert system studies using case-based reasoning in the precedent case-based expert system studies, and their usefulness was verified through experiments. Among the various dimensionality reduction techniques, similar cases were retrieved by applying three algorithms: Non-negative Matrix Factorization(NMF), Latent Semantic Analysis(LSA), and Doc2Vec to extract the characteristics of the failure and measure the cosine distance between the vectors. The precision, recall, and F-measure methods were used to assess the performance of the proposed actions. To compare the performance of dimensionality reduction techniques, the analysis of variance confirmed that the performance differences of the five algorithms were statistically significant, with a comparison between the algorithm that randomly extracts failure cases with identical failure codes and the algorithm that applies cosine similarity directly based on words. In addition, optimal techniques were derived for practical application by verifying differences in performance depending on the number of dimensions for dimensionality reduction. The analysis showed that the performance of the cosine similarity was higher than that of the dimension using Non-negative Matrix Factorization(NMF) and Latent Semantic Analysis(LSA) and the performance of algorithm using Doc2Vec was the highest. Furthermore, in terms of dimensionality reduction techniques, the larger the number of dimensions at the appropriate level, the better the performance was found. Through this study, we confirmed the usefulness of effective methods of extracting characteristics of data and converting unstructured data when applying case-based reasoning based on which most of the attributes are texted in the special field of KTX rolling stock. Text mining is a trend where studies are being conducted for use in many areas, but studies using such text data are still lacking in an environment where there are a number of specialized terms and limited access to data, such as the one we want to use in this study. In this regard, it is significant that the study first presented an intelligent diagnostic system that suggested action by searching for a case by applying text mining techniques to extract the characteristics of the failure to complement keyword-based case searches. It is expected that this will provide implications as basic study for developing diagnostic systems that can be used immediately on the site.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.1
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• pp.48-61
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• 2000

Korea Aerospace Research Institute (KARI) have gained experience with Helicopter Vibration Health Monitoring (VHM) System technology with the help of UK GKN-WHL. GKN-WHL have had many years of experience with the research and development of vibration analysis techniques to improve the health monitoring of helicopter transmissions. This activity was targeted at transmission rig testing at first, but the techniques have been progressively developed where they are now used as a part of integrated Health and Usage Monitoring (HUM) systems on many types of in-service and new helicopters. The technique development process has been considerably aided by an ever expanding database of transmission monitoring experience from both the rig testing and aircraft operations. This experience covers a wide range of failure types from naturally occurring faults to crack propagation studies and covering a wide range of transmission configurations. Primarily based on accelerometer signals GKN-WHL's vibration analysis methods have also been applied to a variety of other sensor types. The transition from an experimental environment to operational VHM systems has been a lengthy process, there being a need to demonstrate technique reliability as well as effectiveness to both regulatory (Airworthiness Authority) and commercial organizations. Another important feature of this process has been the development of close relationships with a number of VHM system hardware and software suppliers. Such an experienced GKN-WHL provides various raw vibration data which was acquired from transmission ground test rig and allow KARI to develop it's own analysis program. KARI made a program and then analyzed the data to coma pre with the results of GKN-WHL. The KARI's results both time domain signals and statistical values show comparable to GKN's.

• Tuberculosis and Respiratory Diseases
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• v.68 no.2
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• pp.62-66
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• 2010

Background: Extracorporeal membrane oxygenation (ECMO) during severe acute respiratory failure helps to recover the pulmonary function. This study evaluated our experience with veno-venous ECMO in adult patients with acute respiratory failure. Methods: From January 2007 to July 2009, ECMO was used on 54 patients. Of these 54 patients, 7 were placed on veno-venous ECMO for acute respiratory failure. The indications of ECMO were based on the lung dysfunction measured as a $PaO_2/FiO_2$ ratio <100 mm Hg on $FiO_2$ of 1.0, or an arterial blood gas pH <7.25 due to hypercapnia despite the optimal treatment. $EBS^{(R)}$, $Bio-pump^{(R)}$, and Centrifugal Rotaflow $pump^{(R)}$ were used and all cannulations were performed percutaneously via both femoral veins. When the lung function was improved, an attempt was made to wean on ECMO at moderate ventilator settings followed by decannulation. Results: Five of the 7 patients were male and the mean age was $46.3{\pm}18.3$. The causes of acute respiratory failure were 3 cases of pneumonia, 2 near-drownings, 1 pulmonary hemorrhage due to acute hepatic failure and 1 mercury vapor poisoning. The mean support time of ECMO was $17.3{\pm}13.7$ days. Of the 7 patients implanted with ECMO, 5 patients (71%) were weaned off ECMO and 3 patients (43%) survived to hospital discharge after a mean 89.6 hospital days. Conclusion: The early use of ECMO for acute respiratory failure in adults due to any cause is a good therapeutic option for those unresponsive to the optimal conventional treatments.

• Journal of Korea Technology Innovation Society
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• v.15 no.1
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• pp.203-223
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• 2012

This study aimed to identify the factors of failure in cases where there was feasibility but was not successful in commercializing technology. For the study, 92 feasibility reports for new technologies were collected, and among these 4 studies that showed definite failure in commercialization of technology were analyzed in depth. Further analysis was based the factors pointed out by previous frameworks such as 1) discussion on success or failure in commercialization of technology, 2) that of venture company, and 3) valuation of technology studies. Previous studies pointed out success and failure factors as lack of funding, uncontrollable accidents, managing ability, inability for mass production and so forth, which had little difference to the pre-feasible evaluation of four cases. However, real reason was the lack of understanding technologies such as composition of technologies, production technologies required by stages, and lack of understanding of floor technologies. The misunderstandings were occurred regardless of CEO's experience and expertise. We did not touch the evaluation model of pre-feasibility studies, although we dealt with the failure of the pre-studies. The reason we do not generalize the results of this study is the fact that we dealt with only small cases.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.13-26
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• 2019

There is a growing interest in the entrepreneurial activity that has long been considered essential for sustainable economic development and value creating. Although it is strongly encouraged by focusing on the positive aspects of venturing, less has been paid attention to entrepreneurial failure, which is the biggest cause of hesitation in starting a business. The uncertain and risky nature of entrepreneurship implies a considerable possibility of failure. Even if it fails, the experience and knowledge of entrepreneurs acquired through entrepreneurship indeed offers valuable lessons for the re-venturing, which can serve as an important social asset that should not be lost. It has been argued that re-entering the same industry for the subsequent venture maximizes the learning effect through utilizing potential benefits from industry-specific knowledge. Although the re-startup after entrepreneurial failure is a very important topic in the studies on serial entrepreneurs, there is a paucity of systematic empirical investigation. This study responds to calls for more research on the re-startup after entrepreneurial failure, and specifically complements existing studies on serial entrepreneurs. Focusing on the entrepreneurs' attribution for the failure, we conducted an empirical analysis of how this affects the re-startup process. Moreover, we also examined the moderating effects of entrepreneurial self-efficacy and resilience. For the analyses, we surveyed the entrepreneurs who tried to re-start the subsequent business after the entrepreneurial failure through the "Revitalization Center for Strained Entrepreneur". The results found that failed entrepreneurs who blamed internal factors for their previous venture failures were likely to keep the same industry for their subsequent business. In addition, the positive effect of internal attribution on maintaining the same industry for the re-startup was found to be stronger when entrepreneurial self-efficacy and resilience were high.

• Journal of Korean Physical Therapy Science
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• v.9 no.1
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• pp.69-80
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• 2002

The objective of research provides the physical therapy of good quality to the patients to search for the problem pant against a physical therapy accident and it simultaneously respects physical therapy company law, the possibility of preparing a system defensive ability in order to be. The data were collected from 2000 October 1 to December 30th, and analyzed by a frequency and a percentage, oneway ANOVA, Scheffe method, $x^2$ official approvals. Conclusion (1) the accident where the patient falls from inside the treatment 'room is many and occasionally' 29.3% (63 people) with was many most. (2) Because of a mistake by a part-time therapist in holiday or a colleague therapist to do, the fracture or bum accident happens 12.5% (27 people), by a assist nurse due to more showed 12.1% (26 people) experience degree in the patient. (3) From physical therapy process breakdown of the medical treatment machinery and tools or it is in malfunction to do and the experience which has a failure to physical therapy is one enemy 68.1% (147 people) was in item. Also it treats and the patient or in the protector it sends an explanation in advance not to be, the experience which it enforces 50% (108 people), of service hour treatment equipment the medical treatment directives broad way of the doctor is accurate in insufficiency and does not enforce the experience is 45.4% (98 people), the patient whom I am treating Hot Pack (electricity has pack inclusion) with to do, the art dealer (over at 1 buffoonery) the experience which it puts on 27.1% (58 people), The patient whom I am treating is the electrotherapy flag (electricity has pack exclusion) with to do, the art dealer (1 degree art dealer over) the experience which it puts on 16.3% (35 people), the experience boat song the patient against a fracture from physical therapy process 9 person (4.2%) was visible an experience degree. (4) With hospital infection to do, from the patient the experience and the therapist which receive a problem proposal were caused by with hospital infection and the answer back regarding the experience which tries to receive a treatment appeared 6% (13 people), 42% (9 people) with each. (5) It listened to the treatment hour patient or the appeal of the protector and especially it does not appear to be being important it was not and and the management which is special it did not take, also the experience where the condition of the patient is deteriorated after that was 10.3% (22 people). (6) The condition or state of the patient does not agree with the medical treatment instruction of the doctor not to be, amendment one experience was 67.5% (145 people). (7) The experience degree of the physical therapy accident which relates with physical therapy recording and a secret maintenance 59.7% (129 people) 'is many and occasionally it is,' it showed an answer back and e it showed a most high accident experience degree. (8) The business overweight of physical therapy company 43.3% (93 people) with was high most from recognition degree of the physical therapy company against a physical therapy accident. (9) Against the question which asks the responsibility subject matter of physical therapy accident the whole answer back volition 42.8% did it is a joint responsibility where the multi person relates. (10) The accident occurs most the hour unit which plentifully in the afternoon 64.3% (133 people) with appeared from the recognition degree against the frequency hour unit of physical therapy accident. (11) Physical therapy it bought and after the various medical treatment accident which relates against the attitude of the, patient side against the physical therapy company it understood and trillion it was many most with 33.3% to be finished. (12) After physical therapy accident the management against the physical therapy company of the hospital authorities concerned above all do not experience 70.6% (149 people), from event right and wrong submission 22.7% (48 people), warning management 2.8% (6 people), the event report requirement and money compensation were each 0.5% (1 person). (13) As the prevention book of physical therapy accident most it is important, the fact which it thinks that, the persons supplement of physical therapy company 58.8% (127 people) with was high most. (14) It related with a physical therapy accident and the medical law 43.5%, civil law 23.9%, was visible the answer back ratio of the criminal law 13.7% from the degree which probably is a relation law.

• Korean Business Review
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• v.17
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• pp.215-230
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• 2004

A lot of companies experience failure in innovating their management practices even though they adopt various innovation techniques that seem to be valid and competitive. The primary reason for this failure can be found from the fact that the company failed to conduct innovation techniques in harmony with their business strategies. In this context, we focus on developing a unified framework that innovates the management practices in accordance with the business strategies of the company. For this purpose, we first analyse numerous innovation techniques and business strategies, and then classify them into several clusters in terms of 'innovation technique-strategy" match. Therefore, the result of this work can be used as a guide to derive competitive innovation techniques that are compatible with the underlying business strategies.

• Journal of Chest Surgery
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• v.18 no.1
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• pp.36-45
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• 1985

During the twelve-year period from March 1973 through July 1984, 23 consecutive operations for coarctation of the aorta were performed at Seoul National University Hospital. The patients included 19 male and 4 female in the range of 4 months and 16 years old. Associated cardiac anomalies were present in 19 patients [70%] and they were VSD+PDA [9 patients], VSD[2], PDA[1], VSD+ASD+PDA[1], VSD+MS+AS+PDA[1], D-TGA+VSD+PDA[1], P-ECD[1], MS[1], Al[1], and DORV+PDA[1]. The preoperative main symptoms included congestive heat failure, hypertension, subacute bacterial endocarditis and nonspecific symptoms. Congestive heart failure was the most common symptom in the group younger than 2 years and hypertension in the adult group. Operative techniques for coarctation of the aorta were resection and end to end anastomosis in 10 patients, prosthetic patch aortoplasty in 8, subclavian flap aortoplasty in 4, and LSCA-aortic anastomosis in 1. There were 4 operative deaths among the nine patients less than 2 years old[44.4% mortality]: all of these patients had associated cardiac anomalies. And only one operative death occurred in patients older then 2 years old[7.1% mortality]. No hospital death occurred in patients with isolated coarctation of the aorta. Operation of the coarctation was performed primarily in 6 patients associated with ventricular septal defect and subsequently underwent successful VSD closure except one operative death.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.9
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• pp.273-302
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• 1998

INTERNATIONAL MONITORY FUNDS wave swept the Economic structural insolvency lies one upon another with low growth, low trust, low prices, low interest and low employment as[2 down 3 up] phenomenons have been distinguished and low enterprise a control of structures due to forecasting 200 million unemployment, including 600 million unemployed the head of a family population have a difficulty in their life. Only way to give them hope is through the commencement of an enterprises to have 2nd career development. But end of 1995, 467,00 dining out companies have been established and recently business are in depression. There are many business conditions of change of business or reduce operations, if unemployment populations of 5%, 100,000 peoples doing the commencement of an enterprises, enormous number of dining out companies will be increased and the competition will be fierce, especially those who have short knowledge and experience doing the commencement of an enterprises have high failure than success which will give a problems to society. Our study is to make the commencement of an enterprise to reducing the faiure and to be successful for main point to successful commencement of an enterprise, the established can self capability and mental condition, the main important factor is types of industry selection, successful and those established who takes this conditions will very carefully inspect various matters by scientifically and rationally mind industrys propulsion graphs and open official fixture graphs will framing detail factors. One by inspect the reduction of failure, and successful commencement of an enterproses mind industry have been studied.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.114-119
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• 2007

Sulfide stress cracking (SSC) of materials exposed to oilfield environment containing hydrogen sulfide $(H_{2}S)$ has been recognized as a materials failure problem. Laboratory data and field experience have demonstrated that extremely low concentration of $H_{2}S$ may be sufficient to lead to SSC failure of susceptible materials. In some cases, $(H_{2}S)$ can act synergistically with chlorides to produce corrosion and cracking failures. SSC is a form of hydrogen embrittlement that occurs in high strength steels and in localized hard zones in weldment of susceptible materials. In the heat-affected zones adjacent to welds, there are often very narrow hard zones combined with regions of high residual stress that may become embrittled to such an extent by dissolved atomic hydrogen. On the base of understanding on sulfide stress cracking and its mechanism, SSC resistance for the several materials, those are ASTM A106 Gr B using in the oil industries, are evaluated.