• Title/Summary/Keyword: Multiple-Case Study

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Refractory Achilles Tendinopathy and Multiple Pain on the Tendon and Tendon Attachment Site of the Foot Related to Intermittent Levofloxacin Usage: A Case Report (간헐적 Levofloxacin 약제 사용과 관련된 난치성 아킬레스건병증과 족부의 다발성 건 및 건 부착부 통증: 증례 보고)

  • Seung Jun Park;Jin Soo Suh;Jun Young Choi
    • Journal of Korean Foot and Ankle Society
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    • v.27 no.3
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    • pp.103-107
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    • 2023
  • Quinolone antibiotics are frequently prescribed for suspected respiratory or urinary tract infections because of their effectiveness and generally perceived safety profile. On the other hand, some studies have raised concerns regarding the potential association between quinolone use and Achilles tendinopathy or tendon rupture. There is a lack of reports on the link between quinolone use and multiple tendon and tendon attachment site pain in the foot and ankle joints; hence, this study examined this issue further. This paper presents a case report of a patient with persistent Achilles tendinopathy and multiple tendon and tendon attachment site pain in the foot who did not respond adequately to conservative treatments. In particular, the discontinuation of quinolone use resulted in favorable clinical outcomes. This report offers valuable insights into the potential risks associated with quinolone antibiotics and highlights the importance of vigilance when managing patients with tendon-related complaints. A comprehensive review of the relevant literature is also presented to contextualize these findings.

A Distance Education System for Supporting Learners' Interaction (학습자 주도의 상호작용을 지원하는 원격 교육시스템)

  • Jang, Si-Woong;Jeon, Won-Bae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.657-660
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    • 2007
  • With progress of informationalization, education has been transformed from traditional uni-direction education to bi-directional and consumer-oriented education, which is performed by learner's self study and interactive education of multiple dimension between a learner and contents, between a learner and a teacher, and between a learner and a learner irrespective of space-time. According to this trend, a new education method has been required. Therefore, in this paper, we will propose real-time consumer-oriented distance education system of making interaction maximum using WBI. In this system, a learner can participate in an individual study case by multiple interaction with a learner's designing and plaining study, and also participate in group study case by way of discussion and conversation among participants.

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Effect of multiple-failure events on accident management strategy for CANDU-6 reactors

  • YU, Seon Oh;KIM, Manwoong
    • Nuclear Engineering and Technology
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    • v.53 no.10
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    • pp.3236-3246
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    • 2021
  • Lessons learned from the Fukushima Daiichi nuclear power plant accident directed that multiple failures should be considered more seriously rather than single failure in the licensing bases and safety cases because attempts to take accident management measures could be unsuccessful under the high radiation environment aggravated by multiple failures, such as complete loss of electric power, uncontrollable loss of coolant inventory, failure of essential safety function recovery. In the case of the complete loss of electric power called station blackout (SBO), if there is no mitigation action for recovering safety functions, the reactor core would be overheated, and severe fuel damage could be anticipated due to the failure of the active heat sink. In such a transient condition at CANDU-6 plants, the seal failure of the primary heat transport (PHT) pumps can facilitate a consequent increase in the fuel sheath temperature and eventually lead to degradation of the fuel integrity. Therefore, it is necessary to specify the regulatory guidelines for multiple failures on a licensing basis so that licensees should prepare the accident management measures to prevent or mitigate accident conditions. In order to explore the efficiency of implementing accident management strategies for CANDU-6 plants, this study proposed a realistic accident analysis approach on the SBO transient with multiple-failure sequences such as seal failure of PHT pumps without operator's recovery actions. In this regard, a comparative study for two PHT pump seal failure modes with and without coolant seal leakage was conducted using a best-estimate code to precisely investigate the behaviors of thermal-hydraulic parameters during transient conditions. Moreover, a sensitivity analysis for different PHT pump seal leakage rates was also carried out to examine the effect of leakage rate on the system responses. This study is expected to provide the technical bases to the accident management strategy for unmitigated transient conditions with multiple failures.

A Study on Definition and Measurement of Customer Utility based on Attributes of Multiple Generation Technology: Case of 45nm and 32nm Logic Semiconductor (다세대 기술의 속성 기반 고객효용도(Customer utility) 정의 및 측정에 대한 연구: 45nm 및 32nm 로직 반도체 기술 사례)

  • Park, Changhyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.260-266
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    • 2018
  • The concept of customer utility, which affects customer's adoption, is important to understand the process of technology diffusion and substitution regarding multiple generation technology. This research defined the concept of attribute-based customer utility and developed a model for measuring attribute-based customer utility. Based on the literature review and modeling, we provided the definition and a model regarding customer utility and the accuracy of the model is verified through a case study of the semiconductor industry. Customer utility for a multiple generation technology needs to consider changes by generation, or time within the same generation, and is defined as the summation of both technological and economic utilities. In addition, we can model the measurement of customer utility after converting technological and economical attributes into utilities. This research is valuable in understanding not only customer utility as a driver of customer adoption, but also for establishing technological strategy after forecasting diffusion and substitution paths based on customer utility.

Optimal path planning and analysis for the maximization of multi UAVs survivability for missions involving multiple threats and locations (다수의 위협과 복수의 목적지가 존재하는 임무에서 복수 무인기의 생존율 극대화를 위한 최적 경로 계획 및 분석)

  • Jeong, Seongsik;Jang, Dae-Sung;Park, Hyunjin;Seong, Taehyun;Ahn, Jaemyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.6
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    • pp.488-496
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    • 2015
  • This paper proposes a framework to determine the routes of multiple unmanned aerial vehicles (UAVs) to conduct multiple tasks in different locations considering the survivability of the vehicles. The routing problem can be formulated as the vehicle routing problem (VRP) with different cost matrices representing the trade-off between the safety of the UAVs and the mission completion time. The threat level for a UAV at a certain location was modeled considering the detection probability and the shoot-down probability. The minimal-cost path connecting two locations considering the threat level and the flight distance was obtained using the Dijkstra algorithm in hexagonal cells. A case study for determining the optimal routes for a persistent multi-UAVs surveillance and reconnaissance missions given multiple enemy bases was conducted and its results were discussed.

Did the Timing of State Mandated Lockdown Affect the Spread of COVID-19 Infection? A County-level Ecological Study in the United States

  • Trivedi, Megh M.;Das, Anirudha
    • Journal of Preventive Medicine and Public Health
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    • v.54 no.4
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    • pp.238-244
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    • 2021
  • Objectives: Previous pandemics have demonstrated that several demographic, geographic, and socioeconomic factors may play a role in increased infection risk. During this current coronavirus disease 2019 (COVID-19) pandemic, our aim was to examine the association of timing of lockdown at the county level and aforementioned risk factors with daily case rate (DCR) in the United States. Methods: A cross-sectional study using publicly available data was performed including Americans with COVID-19 infection as of May 24, 2020. The United States counties with >100 000 population and >50 cases per 100 000 people were included. The independent variable was the days required from the declaration of lockdown to reach the target case rate (50/100 000 cases) while the dependent (outcome) variable was the DCR per 100 000 on the day of statistical calculation (May 24, 2020) after adjusting for multiple confounding socio-demographic, geographic, and health-related factors. Each independent factor was correlated with outcome variables and assessed for collinearity with each other. Subsequently, all factors with significant association to the outcome variable were included in multiple linear regression models using stepwise method. Models with best R2 value from the multiple regression were chosen. Results: The timing of mandated lockdown order had the most significant association on the DCR per 100 000 after adjusting for multiple socio-demographic, geographic and health-related factors. Additional factors with significant association with increased DCR include rate of uninsured and unemployment. Conclusions: The timing of lockdown order was significantly associated with the spread of COVID-19 at the county level in the United States.

Multichannel Strategies: A Case Study of the Korean Musical Myeongdong Romance

  • AHN, Sung-sook;PARK, Yoon-joo
    • Journal of Distribution Science
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    • v.20 no.1
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    • pp.109-114
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    • 2022
  • Purpose: The purpose of this study is to confirm that multichannel distribution strategies may be used for cultural and artistic products such as musicals, just as for general consumer goods, through a case study on the distribution strategy for a musical title. In addition, a distribution strategy for cultural and artistic products is proposed based on the analysis of the case. Research design, data, and methodology: Qualitative research methods, such as case study research and in-depth interviews, were used in this study. Results: The case study of the Korean musical Myeongdong Romance confirmed that multichannel distribution strategies may be used for musicals, including performances at theaters, Naver TV screenings (a service linked to an Internet portal), LGU+ screenings (an IPTV and OTT media service), DVD releases, and screenings of recordings of Romance Hall performances. Conclusion: For cultural and artistic products such as musicals, distribution channels can be diversified to incorporate the simultaneous use of multiple channels. New cases involving other cultural and artistic products and services to which this distribution strategy is applicable may be identified, and the strategy may be implemented along with new technologies to reduce costs further.

Relation of Multiple Neurogenic Tumors in the Spinal Canal to Neurofibromatosis

  • Seol, Ho-Jun;Chung, Chun-Kee;Kim, Hyun-Jib;Lee, Yoon-Kyung;Park, Sung-Hye
    • Journal of Korean Neurosurgical Society
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    • v.38 no.1
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    • pp.16-22
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    • 2005
  • Objective : The authors characterize a syndrome of multiple neurogenic tumors in the spinal canal, which is unclassifiable by the current National Institute of Health[NIH] criteria for neurofibromatosis. Methods : We retrospectively examined cases in which two or more spinal neurogenic tumors were detected by magnetic resonance[MR] imaging and which had been pathologically confirmed. Eighteen patients were recruited between February 1986 and March 2002. According to NIH criteria, eight cases were neurofibromatosis type 1[NF1], four were type 2[NF2], and six were neither type 1 nor type 2 [Unclassifiable : UC]. The locations of lesions, clinical presentations, radiological findings, and pathological results with immunohistochemistry were reviewed. Results : In the case of NF2, three of four cases were intradural tumors. Pathological examinations revealed neurilemmomas in two of four NF2 and all of the UC cases. In the case of NF1, pathological examinations showed seven neurofibromas and one neurilemmoma. Concerning UC, the age at presentation was middle-aged to late [mean age 48.5, range 35 to 64], which contrasted with ordinary NF2, where patients tended to become symptomatic before 20years of age. The pathological examinations of UC cases revealed neurilemmoma similar to most of NF2 and the immunohistochemical study showed characteristic of NF1. Conclusion : Multiple neurogenic tumors in the spinal canal are an under-recognized disease entity. Further studies for genetic aberration in multiple spinal neurogenic tumors are needed.

A Study on the Collision Avoidance Maneuver Optimization with Multiple Space Debris

  • Kim, Eun-Hyouek;Kim, Hae-Dong;Kim, Hak-Jung
    • Journal of Astronomy and Space Sciences
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    • v.29 no.1
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    • pp.11-21
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    • 2012
  • In this paper, the authors introduced a new approach to find the optimal collision avoidance maneuver considering multi threatening objects within short period, while satisfying constraints on the fuel limit and the acceptable collision probability. A preliminary effort in applying a genetic algorithm (GA) to those kinds of problems has also been demonstrated through a simulation study with a simple case problem and various fitness functions. And then, GA is applied to the complex case problem including multi-threatening objects. Two distinct collision avoidance maneuvers are dealt with: the first is in-track direction of collision avoidance maneuver. The second considers radial, in-track, cross-track direction maneuver. The results show that the first case violates the collision probability threshold, while the second case does not violate the threshold with satisfaction of all conditions. Various factors for analyzing and planning the optimal collision avoidance maneuver are also presented.

Guideline Construction through Case Study for Applying Crowdsourcing into New Product Development Environment (사례분석을 통한 신제품 개발 환경에서의 크라우드소싱 활용 가이드라인 구축)

  • Kim, Han Jung;Park, Joon Young
    • Journal of Korean Institute of Industrial Engineers
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    • v.39 no.6
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    • pp.517-534
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    • 2013
  • In this study, we propose the guideline with strategic model for new product development. To establish the guideline, 1) we classify several types of successful surveyed cases that achieved open innovation through applying crowdsourcing into new product development environment, 2) draw case maps using two or three axis with characteristics such as: step of product development process, crowdsourcing frequency, and product type of each case, 3) define the type of applying crowdsourcing into new product development environment based on case analysis results, and tabulate a crowdsourcing type based on the defined crowdsourcing type, 4) finally, suggest the guideline with multiple points of view which embrace type of crowd, community management, participation method, knowledge adoption method, and reward policy. Using the suggested guideline will help a company to design and establish open innovation in new business model related to product development area.