• 한국항공우주학회지
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• 제42권9호
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• pp.802-808
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• 2014

학문적 연구개발 목적으로 개발된 MEMS 기술 기반 고체 추력기는 큐브위성에 탑재되어 극한 우주환경에서의 궤도 운용 및 기술검증시험을 실시할 예정이다. 이를 위해서는 고체 추력기가 허용온도 범위 내에 유지되도록 하여 점화시간지연에 따른 점화실패 방지 및 저온에서의 추력기의 구조건전성 확보가 가능하도록 열 제어를 실시하여야 한다. 본 논문에서는 MEMS 고체 추력기의 저온에서의 허용온도 유지를 위해 일반적으로 적용되는 온도센서와 히터를 활용하지 않고 고체 추진제 점화용 마이크로 점화기를 온도제어를 위한 센서 및 히터로 활용하는 효율적 열 제어 방안을 제안하였으며, 궤도 열 해석을 통해 열 제어 방식의 유효성을 입증하였다.

• The Journal of Advanced Prosthodontics
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• 제12권2호
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• pp.67-74
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• 2020

PURPOSE. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.

• 재활간호학회지
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• 제8권2호
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• pp.119-128
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• 2005

Purpose: The purpose of this study was to analyze research in the Korean Journal of Rehabilitation Nursing and to suggest further perspective for rehabilitation nursing research. Method: In this study we reviewed the contents of 134 articles published in this journal from its beginning year 1998 to 2004. Results: The majority of subjects were adult patients. The type of disease were Cerebrovascular Accident, Neuromuscular disease, Cancer patients, Urogenital disease such as Chronic Renal Failure, Spinal cord injury. Domain of research almost was client, type of research were survey(34.3%), quasi experimental study(20.9%), correlation study(19.4%). Nursing intervention of experimental study was exercise(39.0%), education(17.1%). Place of data collection was hospital (58.2%), position of researcher was professor(67.2%), method of data collection was questionnaire(50.7%). Conclusion: There has been a lack of written consent, child rehabilitation, measurement tool development, qualitative research. More studies about rehabilitation nursing are needed to extend the role and fields for professional nursing.

• 대한임베디드공학회논문지
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• 제16권6호
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• pp.267-276
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• 2021

The automotive industry and academic research have been continuously conducting research on standardization such as AUTOSAR (AUTomotive Open System ARchitecture) and ISO26262 to solve problems such as safety and efficiency caused by the complexity of electric/electronic architecture of automotive. AUTOSAR is an automotive standard software platform that has a layered structure independent of MCU (Micro Controller Unit) hardware, and improves product reliability through software modularity and reusability. And, ISO26262, an international standard for automotive functional safety and suggests a method to minimize errors in automotive ECU (Electronic Control Unit)s by defining the development process and results for the entire life cycle of automotive electrical/electronic systems. These design methods are variously applied in representative automotive safety-critical systems. However, since the functional and safety requirements are different according to the characteristics of the safety-critical system, it is essential to research the AUTOSAR functional safety design method specialized for each application domain. In this paper, a software functional safety mechanism design method using AUTOSAR is proposed, and a new failure management framework is proposed to ensure the high reliability of the product. The AUTOSAR functional safety mechanism consists of memory partitioning protection, timing monitoring protection, and end-to-end protection. The fault management framework is composed of several safety SWCs to maintain the minimum function and performance even if a fault occurs during the operation of a safety-critical system. Finally, the proposed method is applied to the Shift-by-Wire system design to prove the validity of the proposed method.

• 산업경영시스템학회지
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• 제42권1호
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• pp.64-73
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• 2019

The manufacturing companies under Make-To-Order (MTO) production environment face highly variable requirements of the customers. It makes them difficult to establish preemptive production strategy through inventory management and demand forecasting. Therefore, the ability to establish an optimal production schedule that incorporates the various requirements of the customers is emphasized as the key success factor. In this study, we suggest a process of designing the simulation model for establishing production schedule and apply this model to the case of a flat glass processing company. The flat glass manufacturing industry is under MTO production environment. Academic research of flat glass industry is focused on minimizing the waste in the cutting process. In addition, in the practical view, the flat glass manufacturing companies tend to establish the production schedule based on the intuition of production manager and it results in failure of meeting the due date. Based on these findings, the case study aims to present the process of drawing up a production schedule through simulation modeling. The actual data of Korean flat glass processing company were used to make a monthly production schedule. To do this, five scenarios based on dispatching rules are considered and each scenario is evaluated by three key performance indicators for delivery compliance. We used B2MML (Business To Manufacturing Markup Language) schema for integrating manufacturing systems and simulations are carried out by using SIMIO simulation software. The results provide the basis for determining a suitable production schedule from the production manager's perspective.

• 지식경영연구
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• 제22권1호
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• pp.1-19
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• 2021

대규모 병원정보시스템 프로젝트가 계획 대비 지연되는 경우가 종종 발생하고 있다. 따라서 프로젝트 관리 측면에서 일정 지연을 촉발하는 원인을 검토하고 지연 유발 요인들 간 인과관계 분석이 필요하다. 본 연구는 근거이론 방법론을 활용하여 병원정보시스템 개발 프로젝트 사례에 대한 일정 지연 요인을 발견하고 이들 간의 인과관계를 파악하고자 한다. 연구 결과, '비현실적 일정 수립'은 도미노 현상과 같이 전반적인 일정 지연에 영향을 미치고, '기존 시스템 분석 미흡'은 분석 품질의 저하를 야기하는 반면 '서브시스템 통합 인터페이스 부실'은 설계 품질의 저하로 이어졌다. 본 연구는 학술적인 측면에서 프로젝트 지연에 영향을 미치는 요인을 찾아내고 지연 요인들 간의 인과 관계를 분석하였으며, 실무적 관점에서는 System Integration (SI) 기업, 병원, 프로젝트 관리자 입장에서 프로젝트 일정 지연을 최소화할 수 있는 방안을 제시한 점에 의의가 있다.

• Journal of Ginseng Research
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• 제46권3호
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• pp.337-347
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• 2022

Coronavirus disease 2019 (COVID-19) is currently a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 are directly associated with hyper-activation of innate immune response that excessively produce pro-inflammatory cytokines and induce cytokine storm, leading to multi-organ-failure and significant morbidity/mortality. Currently, several antiviral drugs such as Paxlovid (nirmatrelvir and ritonavir) and molnupiravir are authorized to treat mild to moderate COVID-19, however, there are still no drugs that can specifically fight against challenges of SARS-CoV-2 variants. Panax ginseng, a medicinal plant widely used for treating various conditions, might be appropriate for this need due to its anti-inflammatory/cytokine/viral activities, fewer side effects, and cost efficiency. To review Panax ginseng and its pharmacologically active-ingredients as potential phytopharmaceuticals for treating cytokine storm of COVID-19, articles that reporting its positive effects on the cytokine production were searched from academic databases. Experimental/clinical evidences for the effectiveness of Panax ginseng and its active-ingredients in preventing or mitigating cytokine storm, especially for the cascade of cytokine storm, suggest that they might be beneficial as an adjunct treatment for cytokine storm of COVID-19. This review may provide a new approach to discover specific medications using Panax ginseng to control cytokine storm of COVID-19.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.960-966
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• 2022

Mobility is an essential human need. Human survival and societal interaction depend on the ability to move people and goods. Efficient mobility systems are essential facilitators of economic development. Cities could not exist and global trade could not occur without systems to transport people and goods cheaply and efficiently. Rail has been considered as one of the important components of the transportation infrastructure required to service and improve the performance and productivity of an economy. In Nigeria, the rail infrastructure built by the colonial master several decades ago has been left in a state of total deterioration. This long neglect was occasioned by the failure of the government to pay adequate attention to infrastructure development. There is a vital and urgent need for rail infrastructure development in Nigeria. This study presents a systematic review of the evolution of rail, the current nature of railway infrastructure delivery in Nigeria, and offers possible suggestions on how to achieve an effective and sustainable rail infrastructure delivery in Nigeria. A thorough literature search of academic databases was conducted on current research trends on the subject of railway infrastructure by systematically reviewing selected published articles from reputable research domains. The analysis of the selected articles revealed the following among others (1) the existing railway infrastructure is in a state of mess and not sustainable, and (2), Government's investment/commitment in rail infrastructure seems inadequate compared to what is obtainable in other developed countries. Rail infrastructure development cannot be left to the Federal government of Nigeria to solve on its own; collaboration and participation are required. Government as a matter of priority should devote considerable attention to the development of rail infrastructure to harness the economic potential and transformation that sustainable rail infrastructural projects will provide.

• Asia Marketing Journal
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• 제10권1호
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• pp.1-23
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• 2008

고객만족경영을 통하여 기업이 이윤의 증진을 도모하는 것은 자명한 일이다. 따라서 고객만족과 기업성과와의 직접적인 관계를 밝히는 것은 학술적으로나 실무적으로 매우 중요하다. 고객만족이 기업경영성과에 미치는 영향에 관한 지금까지의 연구에서는 주로 당기의 고객만족이 당기의 기업경영성과에 미치는 현재효과를 분석하였다. 그러나 마케팅활동이 동태적 효과를 갖는다는 연구에 의하면 고객만족이 현재뿐만 아니라 미래의 기업 경영성과에 미치는 동태적 효과의 검증이 필요하다. 만약 이 효과가 존재함에도 불구하고 이를 충분히 측정하지 못한다면 고객만족의 효과는 낮게 평가될 것이다. 이에 본 연구에서는 패널자료분석을 통하여 기업의 수익성과 기업가치에 미치는 고객만족의 동태적 효과를 추정하였다. 연구결과, 고객만족은 기업의 수익성과 기업가치에 긍정적인 영향을 주며, 동태적 효과를 갖는 것으로 분석되었다. 또한 모형 추정결과, 모형의 적합도에서 이유재와 이청림(2006)보다 개선이 이루어 졌다. 한편 고객만족의 과거 항을 2기까지 추가한 비교모형은 추정결과의 해석이 어렵고, 다중공선성 문제가 있는 것으로 분석되었다.

• The Journal of Advanced Prosthodontics
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• 제16권2호
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• pp.77-90
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• 2024

PURPOSE. The study aims to investigate the influence of the ferrule effect and types of posts on the stress distribution in three morphological types of the maxillary central incisor. MATERIALS AND METHODS. Nine models were created for 3 maxillary central incisor morphology types: "Fat" type - crown 12.5 mm, root 13 mm, and buccolingual cervical diameter 7.5 mm, "Medium" type - crown 11 mm, root 14 mm, and buccolingual cervical diameter 6.5 mm, and "Slim" type - crown 9.5 mm, root 15 mm, and buccolingual cervical diameter 5.5 mm. Each model received an anatomical castable post-and-core or glass-fiber post with resin composite core and three ferrule heights (nonexistent, 1 mm, and 2 mm). Then, a load of 14 N was applied at the cingulum with a 45° slope to the long axis of the tooth. The Maximum Principal Stress and the Minimum Principal Stress were calculated in the root dentin, crown, and core. RESULTS. Higher tensile and compression stress values were observed in root dentin using the metallic post compared to the fiber post, being higher in the slim type maxillary central incisor than in the medium and fat types. Concerning the three anatomical types of maxillary central incisors, the slim type without ferrule height in mm presented the highest tensile stress in the dentin, for both types of metal and fiber posts. CONCLUSION. Post system and tooth morphology were able to modify the biomechanical response of restored endodontically-treated incisors, showing the importance of personalized dental treatment for each case.