• Journal of Korean Institute of Industrial Engineers
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• v.34 no.3
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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.

• Journal of Korean Medicine Rehabilitation
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• v.26 no.3
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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.

• Korean Journal of Remote Sensing
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• v.35 no.6_2
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• pp.1095-1106
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• 2019

Damage of forest fire should be investigated quickly and accurately for recovery, compensation and prevention of secondary disaster. Using remotely sensed data, burn severity is investigated based on the difference of reflectance or spectral indices before and after forest fire. Recently, the use of high resolution satellite and UAV imagery is increasing, but it is not easy to obtain an image before forest fire that cannot be predicted where and when. This study tried to analyze availability of high-resolution images and supervised classifiers on the burn severity classification. Two supervised classifiers were applied to the KOMPSAT-3A image and the UAV multispectral image acquired after the forest fire. The maximum likelihood (MLH) classifier use absolute value of spectral reflectance and the spectral angle mapper (SAM) classifier use pattern of spectra. As a result, in terms of spatial resolution, the classification accuracy of the UAV image was higher than that of the satellite image. However, both images shown very high classification accuracy, which means that they can be used for classification of burn severity. In terms of the classifier, the maximum likelihood method showed higher classification accuracy than the spectral angle mapper because some classes have similar spectral pattern although they have different absolute reflectance. Therefore, burn severity can be classified using the high resolution multispectral images after the fire, but an appropriate classifier should be selected to get high accuracy.

• Korea Journal of Hospital Management
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• v.17 no.3
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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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• v.12 no.4
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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.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.29 no.1
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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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• 2009.05a
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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.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.2_1
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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.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.63-73
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• 2011

The purpose of this study was to suggest the education and training program for disaster management by comparison between DACUM technique applied curriculum and curriculum by expert committee, and curriculum development. First, DACUM technique applied curriculum development. Job Classification of Disaster management was consisted of four jobs - mitigation, preparedness, response and recovery - by three times discussions of expert panels. Job analysis and curriculum development were performed by the DACUM panels who consisted of three subject-matter experts and one educational expert on each field. Curriculum developed mitigation was nine courses, preparedness was twelve courses, response was seven courses, and recovery was four courses. Second, Expert committee developed curriculum. Expert committee consisted of five experts and three educational expert. Expert committee was held four times. Curriculum developed thirty five courses. Then disaster management curriculum determined by discussion of experts. disaster management curriculum considered (1)mitigation and preparedness was thirty one courses, (2)response and recovery was fourteen courses, (3)man-made was six courses, (4)manager level was four courses.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.883-896
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• 2023

As human activities in Korea are spread throughout the mountains, forest fires often affect residential areas, infrastructure, and other facilities. Hence, it is necessary to detect fire-damaged areas quickly to enable support and recovery. Remote sensing is the most efficient tool for this purpose. Fire damage detection experiments were conducted on the east coast of Korea. Because this area comprises a mixture of forest and artificial land cover, data with low resolution are not suitable. We used Sentinel-2 multispectral instrument (MSI) data, which provide adequate temporal and spatial resolution, and the k-nearest neighbor (kNN) algorithm in this study. Six bands of Sentinel-2 MSI and two indices of normalized difference vegetation index (NDVI) and normalized burn ratio (NBR) were used as features for kNN classification. The kNN classifier was trained using 2,000 randomly selected samples in the fire-damaged and undamaged areas. Outliers were removed and a forest type map was used to improve classification performance. Numerous experiments for various neighbors for kNN and feature combinations have been conducted using bi-temporal and uni-temporal approaches. The bi-temporal classification performed better than the uni-temporal classification. However, the uni-temporal classification was able to detect severely damaged areas.