• Hip & pelvis
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• v.36 no.3
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• pp.196-203
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• 2024

Purpose: The direct anterior approach (DAA) for conducting total hip arthroplasty (THA) is gaining popularity worldwide. However, careful selection of patients and surgeon experience are important. Although promising outcomes have been reported in international studies, research on DAA in Southern and Southeast Asia has been limited. Materials and Methods: This prospective study included 157 patients who underwent THA using the DAA between January 2019 and June 2022. The patients were divided into three groups for the comparison. Data on preoperative, intraoperative, and postoperative variables were acquired. Improvement of the surgeon's performance to use of a DAA approach was examined using the CUSUM (cumulative summation method). Results: The mean age of the patients was 43.9 years. Differences in intraoperative variables and complications were observed among the three groups, and improved outcomes were reported in later cases. Functional outcomes showed significant improvement, and no differences were observed between groups. The results of learning curve analysis indicated a shift towards consistent success after the 82nd case, reaching an acceptable rate of failure by the 118th case. Conclusion: The findings of this study suggest that DAA can offer benefits but there is a learning curve. Complications were initially high but began decreasing after approximately 80 cases. Careful selection of patients is critical, particularly in the effort to minimize being presented with a challenging case. This study provides insights that may be helpful to surgeons when considering DAA; however, further study is warranted.

• Journal of Korean Foot and Ankle Society
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• v.18 no.4
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• pp.189-194
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• 2014

Purpose: The purpose of this study was to compare the clinical and radiologic results of arthrodesis between anterior approach and transfibular approach arthrodesis in ankle arthritis. Materials and Methods: There were 61 cases of ankle arthritis treated by anterior or transfibular ankle arthrodesis in our hospital from April 2008 to March 2012. We investigated 29 cases (27 patients) who underwent ankle arthrodesis with an anterior approach (15 cases) and transfibular approach (14 cases), and were followed for over two years. Clinically, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, pain visual analogue scale (VAS), and subjective satisfaction degrees were evaluated. In addition, ankle coronal and sagittal alignments were evaluated using plain radiographs at 6 and 24 months, postoperatively. Results: Clinically, preoperative mean AOFAS score and VAS was 41.3 and 6.4, and were changed to 58.9 and 3.3 postoperatively in the anterior approach group. In the transfibular approach group, preoperative mean AOFAS score was 36.6 and VAS was 7.1, and they were changed to 54.9 and 3.4 postoperatively. However, no significant differences in the clinical results were observed between the two groups (p=0.297). Duration of attaining union was 8.1 weeks in the anterior approach group and 10.4 weeks in the transfibular approach group. Complications were delayed union in one case, nonunion in three cases, cancellous screw breakage in three cases, and complex regional reflex syndrome in one case. Conclusion: After transfibular ankle arthrodesis as treatment of ankle osteoarthritis, the tendency for valgus angulation of the ankle at the final follow-up was observed and 6.5 mm cancellous screw breakage occurred frequently. Therefore, in order to achieve better stability, it is necessary to use 6.5 mm cannulated screws rather than 6.5 mm cancellous screws for ankle arthrodesis.

• The Journal of Information Systems
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• v.7 no.1
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• pp.159-180
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• 1998

User-led IS development contributes to the response of actual user needs, the alternative solution for backlog, and including the enhanced communication and the reduced role conflict between users and DP department. However, there are too little research and practical concern about the user-led IS development. This case study on the Korea Real Estate Investment Trust addresses to the development background, IS development process, and the qualitative and quantitative benefit of user-led IS development. We believe that the case study contributes to the understanding for the benefit of user-led IS development approach.

• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.91-109
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• 2004

This study investigates the effectiveness of a hybrid approach using fuzzy sets that describe approximate phenomena of the real world. Compared to the other existing techniques, the approach handles inexact knowledge in common linguistic terms as human reasoning does it. Integration of fuzzy sets with case-based reasoning (CBR) is important in that it helps to develop a successful system far dealing with vague and incomplete knowledge which statistically uses membership value of fuzzy sets in CBR. The preliminary results show that the accuracy of the integrated fuzzy-CBR approach proposed for this study is higher that of conventional techniques. Our proposed approach is applied to corporate bond rating of Korean companies.

• Journal of Construction Engineering and Project Management
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• v.2 no.4
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• pp.42-45
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• 2012

In construction industry, the term 'procurement' is considered as a project based job where clients and contractors are always keen to observe performance indicators. These indicators represent financial and non-financial efficiency of project activities. Among these, the monitoring of financial indicators such as cost monitoring is an ongoing process and its importance cannot be undermined during the project life cycle. It can be monitored by using traditional approach of direct reporting of actual cost against budget. However, the comparison of budget versus actual spending does not indicate the worth of the work which is completed at any given time. This approach does not represent the true cost performance of the project. Because of these limitations, this paper discusses the applications of Earned Value Analysis (EVA) for cost monitoring of construction projects in Malaysia. Besides traditional approach, EVA is a three-dimensional approach that compares three cost indicators i.e. the budgeted value of work scheduled with the earned value of physical work completed and the actual cost of work completed. Therefore, cost monitoring by EVA is an objective measure of actual work performed. This paper uses a case study, an example application of EVA as a cost monitoring tool. This case study reaffirms the benefits of using EVA for project cash flow analysis and forecasting.

• Asia pacific journal of information systems
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• v.16 no.1
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• pp.71-84
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• 2006

Case-based reasoning (CBR) is a reasoning technique that reuses past cases to find a solution to the new problem. It often shows significant promise for improving effectiveness of complex and unstructured decision making. It has been applied to various problem-solving areas including manufacturing, finance and marketing for the reason. However, the design of appropriate case indexing and retrieval mechanisms to improve the performance of CBR is still a challenging issue. Most of the previous studies on CBR have focused on the similarity function or optimization of case features and their weights. According to some of the prior research, however, finding the optimal k parameter for the k-nearest neighbor (k-NN) is also crucial for improving the performance of the CBR system. In spite of the fact, there have been few attempts to optimize the number of neighbors, especially using artificial intelligence (AI) techniques. In this study, we introduce a genetic algorithm (GA) to optimize the number of neighbors to combine. This study applies the novel approach to Korean stock market. Experimental results show that the GA-optimized k-NN approach outperforms other AI techniques for stock market prediction.

• Bulletin of the Korean Chemical Society
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• v.7 no.4
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• pp.271-275
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• 1986

The Smoluchowski equation with a step potential is solved in one-dimensional case and three-dimensional case with spherical symmetry. Exact analytic expressions for the solution and the remaining probability are obtained in one-dimensional case for the reflecting boundary condition and the long time behavior of the remaining probability is compared with the earlier work. In three-dimensional case, only the long time behavior is evaluated. More general case with the radiation boundary condition is also investigated and the results are shown to approach correct limits of the reflecting boundary condition.

• International Journal of Fluid Machinery and Systems
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• v.8 no.1
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• pp.55-62
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• 2015

This study aims to present a hydraulic transitory study as MOC applications for solving the Saint-Venant equations in two case studies: 1) in a penstock of a small hydropower system as a simple pipeline in the case of valve-closure in the downstream boundary with a reservoir in the upstream boundary; and 2) for discharge propagation into a channel by velocity and depth of the flow channel along space evaluation. The proposed methodology by Chaudry [5] concerning the development of hydrodynamic models was used. The obtained results for first and second case study has been confirmed that MOC numerical approach is useful for several engineering purposes, including cases of hydraulic transients and discharge propagation in hydraulic systems.

• Industrial Engineering and Management Systems
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• v.15 no.2
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• pp.181-195
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• 2016

In a product environment where various product-service systems (PSSs) are already being provided, the provision of a different type of PSS is difficult for second movers but necessary for their sustainability and differentiation. Despite the importance of providing distinguishing PSSs to market, prior PSS studies have not effectively considered the influence of existing PSSs in their methods. In response, we suggest an approach to generate new PSS concepts by employing general needs (GNs) and business system evolution patterns (BSEPs). Our approach 1) identifies customer GNs fulfilled by existing PSSs, 2) generates advanced PSS ideas from an evolutionary perspective by mapping the existing PSSs onto BSEPs, and 3) selects PSS ideas that can meet the unfulfilled or insufficiently considered GNs using a GN-PSS linking matrix, thereby generating new PSS concepts based on the selected ideas. The workings and practicability of this approach are illustrated using a PSS case study of furniture industry. This approach would provide PSS planners with an ability to generate the differentiated PSS concepts that handle the customer needs that have been untapped throughout a product's lifecycle. In addition, this approach as a module will have a synergetic effect when incorporated with other PSS methodologies.

• Korean Institute of Interior Design Journal
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• no.19
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• pp.114-120
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• 1999

By taking an ecological approach, The purpose of this thesis was to 1. analyze the existing literary work about design directives for the elderly housing. 2. case study about actual housing conditions of elderly people, 3. grasp the level of satisfaction and level of requirement about housing environment by Korean elderly, 4. by integrating the above three, provide foundational data arranging the appropriate housing design directives pertaining to Korea's actual circumstances. The major findings in this study were surmmarized as follows. (1) From the six literary works, 27 items as Microsystem, 1,249 items as Mesosystem, and 330 items as Exosystem were founded and there was no evidence of directives for Macrosystem. (2) As a result of the case study, there appeared a substantial difference between actual conditions of housing environment for the Korean elderly and the design directives perceived in the literary works. (3) The level of satisfaction and for the Korean elderly housing environment were founded differently in each directives. (4) By ecological approach for the Korean elderly housing environment design directives as follows. In microsystem (13 items) in mesosystem(83 items), in exosystem(24 items), in macrosystem(15 items), 135 items in total were suggested as design directives for Korean Elderly housing environment.