• 대한산업공학회지
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• 제34권3호
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• pp.270-288
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• 2008

Among various environmental issues, those for worn-out products are increasingly important due to rapid development and improvement of products, shortages of dumping sites and waste-incineration facilities, and legislation pressures and customer recognitions to protect the environment. Under such circumstances, collection and product recovery activities give rise to additional material flows from customers back to collectors and reprocessors. Reverse logistics, the opposite direction of the conventional forward logistics, is concerned with the management of this material flow. In this paper, we consider the emerging concept of reverse logistics. First, the concept of sustainable development is explained to explain the philosophical background of various environmental issues. Second, we explain the basics of reverse logistics, which includes the overall structure and the classification of network types. Finally, we review the previous research articles, especially in the aspect of industrial engineering, after classifying the decision problems into : (a) product recovery strategy; (b) network design and operation; (c) inventory management; (d) disassembly problems; and (e) remanufacturing problems.

• 한방재활의학과학회지
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• 제26권3호
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• pp.143-151
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• 2016

A 57-year-old male patient was diagnosed as Incomplete cervical spinal cord injury and Neurogenic bladder after falling accident and suffered from tetraplegia and urinary retention. The patient was hospitalized and treated with Complex Korean Medical treatment such as acupuncture, electro-acupuncture, bee venom pharmacopuncture and herbal medication for 13 weeks. International Standard for Neurological Classification of Spinal Cord Injury (ISNCSCI) was adopted to evaluate the functional recovery and Korean version of Modified Barthel Index (K-MBI) was adopted to evaluate the recovery of activities of daily living (ADL). After treatment, Total scores of ISNCSCI and K-MBI were improved. Also patient's micturition reflex was recovered and symptoms of neurogenic bladder were improved. This result shows that Korean Medical treatment may be an effective treatment option for spinal cord injury and neurogenic bladder patients. Further clinical studies are needed to clarify the effect of Korean Medical treatment on spinal cord injury.

• 대한원격탐사학회지
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• 제35권6_2호
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• pp.1095-1106
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• 2019

산불 피해는 복구, 보상 및 2차 피해 예방을 위해 빠르고 정확히 조사되어야 한다. 원격탐사 기반의 산불 피해강도 조사 방법으로 주로 산불 전과 후의 반사율 및 분광지수의 차이를 비교하고 있다. 최근 고해상도 위성영상 및 무인기 영상의 활용이 증가하고 있으나, 언제 어디에서 발생할지 예측할 수 없는 산불에 대한 발생 전 영상을 획득하는 것이 쉽지 않다. 본 연구에서는 산불 피해강도 분류에 있어 고해상도 영상과 감독분류 기법의 활용 가능성을 분석하고자 하였다. 산불 후에 촬영된 KOMPSAT-3A 영상과 무인기 다중분광영상에 반사율의 절대값을 이용하는 최대우도법과 반사율의 패턴을 이용하는 분광각매퍼의 두 가지 감독분류 기법을 적용하였다. 그 결과 분류 기법 측면에서 최대우도법이 분광각매퍼에 비해 높은 분류정확도를 보여주었으며, 이는 피해강도 등급 간에 분광반사율의 절대값은 다르지만 패턴이 유사한 등급들이 존재하기 때문인 것으로 판단된다. 공간해상도 측면에서 상대적으로 해상도가 높은 무인기 영상의 분류정확도가 위성영상보다 높게 나타났다. 그러나 무인기와 위성 영상 모두 분류정확도가 매우 높게 나타나고 있어 피해강도 분류에 활용 가능성이 높다고 할 수 있다. 따라서, 피해강도 분류에 있어 산불 후에 촬영된 고해상도 영상들을 이용할 수 있을 것으로 판단된다.

• 한국병원경영학회지
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• 제17권3호
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• pp.57-82
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• 2012

The primary purpose of this study is to examine consumers'probing actions to see what information sources consumers search for medical information when there are diverse medical service information channels, and classify consumers by information source. Its secondary purpose is to understand trust of information and attitude toward information by consumer type, value of medical service, satisfaction with medical service, and word-of-mouth intention. This study will concretely identify information utilization patterns of medical consumers, and explain the unique characteristics and behavior of segmented types of medical consumers. The significance of this study lies in the search for ways to establish information channels trusted by consumers for building an efficient medical service market in the future. The results of this study show that consumers were classified by the latent class analysis(LCA) into 5 types: low-level information seekers, word-of-mouth information seekers, mass media information seekers, digital information seekers and diverse information seekers. The reliability of information sources by type of medical consumer was statistically significant, and in the analysis of differences in consumer attitude, there was a statistically significant difference in cognitive responses. The value of medical service was statistically significant in health recovery and medical service word-of-mouth intention.

• Journal of Chest Surgery
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• 제12권4호
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• pp.355-360
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• 1979

Mitral and aortic valve replacement with tricuspid annuloplasty was undertaken in 5 patients out of 38 valvular surgery between the period from Jan. 1977 to May 1979 in the Dept. of Thoracic and Cardiovascular Surgery in Korea University Hospital. All were male patients with age ranging from 18 to 42 years, and preoperative evaluation revealed one case in Class IV, and four cases in Class III according to the classification of NYHA. Preoperative diagnosis was confirmed by routine cardiac study including retrograde aorto- and left ventriculography, and there were two cases with MSi+ASi+Ti, two cases with MSi+Ai+Ti, and one case with Mi+Ai+Ti. Double valve replacement was performed under the hypothermic cardiopulmonary bypass with total pump time of 247 min. in average ranging from 206 min. to 268 min. During aortic valve replacement, left coronary perfusion was done in the first two cases, and cardiac arrest with cardioplegic solution proposed by Bretschneider was applied in the remained three cases. Starr-Edwards, Bjork-Shiley prosthetic valves and Carpentier-Edwards tissue valve were replaced in the aortic area, and Carpentier-Edwards and Angell-Shiley tissue valves were replaced in the mitral area with each individual combination [three prosthetic and two tissue valves in the aortic, and five tissue valves in the mitral area respectively]. Postoperative recovery was uneventful in all cases except one case with hemopericardium, which was managed with pericardiectomy on the postoperative 10th day in good result. Follow-up after double valve replacement of the all five cases for the period from 6 months to 33 months revealed satisfactory adaptation in social activity and occupation with cardiac function of Class I according to the classification of NYHA In all five cases.

• 대한후두음성언어의학회지
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• 제29권1호
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• pp.24-29
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• 2018

Background and Objectives : The purpose of this study was to evaluate the impact of surgical extent on voice using acoustic and aerodynamic measurements in a serially followed thyroidectomy patients. Materials and Method : From October 2015 to January 2017, 108 patients who had undergone thyroid surgery and voice test for preoperative, 2, 3, and 6 months postoperatively were classified into five operative types. The radiological stage preoperatively and histopathological stage postoperatively were classified according to the invasion of thyroid capsule and surrounding tissue. For each classification, the results of the voice analysis according to the period were compared and analyzed. Results : The difference of voice according to surgical extent, radiological stage, and histopathologic stage showed significant difference only with Maximal phonation time (MPT) over time. However, in the analysis of interaction between each classification and period, Phonation threshold pressure (PTP) only showed significant results. Conclusion : Differences in imaging and histopathologic stages have no significant effect on recovery of voice symptoms after thyroid surgery. As the extent of operation increases, the pressure to start vocalization is relatively higher, which also varies with time after surgery.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2009년도 특별 심포지엄
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• pp.35-45
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• 2009

Reservoir Characterization (RC) using 3-D seismic attributes analysis can provide properties of the oil sand reservoirs, beyond seismic resolution. For example, distributions and temporal bed thicknesses of reservoirs could be characterized by Spectral Decomposition (SD) and additional seismic attributes such as wavelet classification. To extract physical properties of the reservoirs, we applied 3-D seismic attributes analysis to the oil sand reservoirs in McMurray formation, in BlackGold Oilsands Lease, Alberta Canada. Because of high viscosity of the bitumen, Enhanced Oil Recovery (EOR) technology will be necessarily applied to produce the bitumen in a steam chamber generated by Steam Assisted Gravity Drainage (SAGD). To optimize the application of SAGD, it is critical to identify the distributions and thicknesses of the channel sand reservoirs and shale barriers in the promising areas. By 3-D seismic attributes analysis, we could understand the expected paleo-channel and characteristics of the reservoirs. However, further seismic analysis (e.g., elastic impedance inversion and AVO inversion) as well as geological interpretations are still required to improve the resolution and quality of RC.

• 한국산업융합학회 논문집
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• 제27권2_1호
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• pp.257-268
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• 2024

Soccer is type of sport that carries a high risk of injury. Injury is not only cause in the unlucky soccer carrier and also team performance as well as financial effects can be worse since soccer is a team-based game. The duration of recovery from a soccer injury typically relies on its type and severity. Therefore, we conduct this research in order to predict the probability of players injury type using machine learning technologies in this paper. Furthermore, we compare different machine learning models to find the best fit model. This paper utilizes various supervised classification machine learning models, including Decision Tree, Random Forest, K-Nearest Neighbors (KNN), and Naive Bayes. Moreover, based on our finding the KNN and Decision models achieved the highest accuracy rates at 70%, surpassing other models. The Random Forest model followed closely with an accuracy score of 62%. Among the evaluated models, the Naive Bayes model demonstrated the lowest accuracy at 56%. We gathered information about 54 professional soccer players who are playing in the top five European leagues based on their career history. We gathered information about 54 professional soccer players who are playing in the top five European leagues based on their career history.

• 한국방재학회 논문집
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• 제11권3호
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• pp.63-73
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• 2011

본 연구는 방재분야의 교육과정 개발을 위해 DACUM 기법을 이용하여 개발한 교육과정과 전문가회의를 통해 개발한 교육 과정을 비교 분석하여 방재분야의 교육과정을 개발하였다. 첫째, DACUM 기법을 이용한 교육과정 개발은 방재분야의 직무를 예방, 대비, 대응, 복구 등 4가지 직무로 구분하고, 각 직무별로 3명의 방재전문가와 1명의 교육전문가가 3회씩의 워크삽을 통해 예방직무에서 9개 과정, 대비 직무에서 12개 과정, 대비 직무에서 7개 과정, 복구 직무에서 4개의 교육과정을 개발하였다. 둘째, 전문가회의를 통해 교육과정을 개발하였다. 전문가회의는 5명의 방재전문가와 3명의 교육전문가가 4회의 회의를 거쳐 35개의 교육과정을 개발하였다. 이를 통해 DACUM 기법과 전문가회의를 통해 도출된 교육과정을 전문가들의 토론을 거쳐 최종적으로 예방 및 대비 직무에서 31개 과정과 대응 및 복구 직무에서 14개의 교육과정을 개발하였으며, 추가적으로 인적재난에서 6개 과정과 관리자별 4개 과정을 개발하였다.

• 대한토목학회논문집
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• 제43권6호
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• pp.883-896
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• 2023

인간 활동 영역이 산지 곳곳에 퍼져 있는 한국에서는 산불이 주거지역이나 각종 시설물을 위협하는 경우가 잦다. 따라서 산불 이후 대책 마련과 피해 복구를 위해 피해 범위를 빠르게 파악할 필요가 있으며, 이러한 경우 원격탐사가 유용한 도구가 될 수 있다. 본 연구에서는 2019년 4월에 발생한 고성·속초 산불 피해지역에 k-nearest neighbor (kNN) 알고리즘을 적용하여 피해 범위를 탐지하는 실험을 수행하였다. 다양한 인공지물을 포함하는 지표와 숲이 혼재된 지역 특성을 고려하여 적절한 공간 해상도와 시간 해상도를 제공하는 Sentinel-2 multispectral instrument (MSI) 자료를 사용하였다. Sentinel-2 MSI의 여섯 밴드와 정규식생지수(NDVI), 정규탄화지수(NBR)를 분류 특성으로 사용하였다. 산불 피해지역과 비피해 지역에서 무작위로 추출된 2,000개 지점 정보를 이용하여 kNN 분류기를 훈련시켰다. 분류 성능을 높이기 위해 데이터에서 특이값을 제거하고 임상도를 병용하였다. 다양한 이웃(neighbor) 수와 분류 특성 조합을 적용하여 산불 후 데이터를 이용한 실험과 산불 전후 데이터 차이를 이용한 실험을 수행하였다. 산불 전후 데이터 차이를 이용하였을 때 더 우수한 분류 성과를 얻을 수 있었지만, 산불 후 데이터만을 이용한 경우에도 피해지역의 범위를 파악할 수 있었다.