• Investigative Magnetic Resonance Imaging
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• 제16권1호
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• pp.1-5
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• 2012

유방 MRI는 유방암의 유방촬영 스크리닝법에 대한 가장 정확한 보완 검사법이다. 아직까지 MRI 스크리닝의 효과에 대한 무작위 대조군연구가 없음에도 불구하고, 현재 미국암학회와 국립 종합암네트워크 (NCCN)에서는 MRI 스크리닝을 유방암 고위험여성에서 권고하고 있다. 국내에서는, 한 후향적 연구에서 유방암 환자의 반대쪽 유방암에 대한 MRI 스크리닝법이 유방촬영술과 초음파에서 발견하지 못한 암을 발견하고 이는 이후 유방암 발병을 감소시킴을 보고하고 있다. 국내에 유방촬영 스크리닝법의 보완법으로 MRI를 도입하기 위해서는 판독의 표준화와 교육, MR 유도하 조직검사법과 적절한 적응증의 확립, 비용-효용성에 대한 평가가 선결되어야 한다.

• 한국콘텐츠학회논문지
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• 제11권6호
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• pp.326-336
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• 2011

이 연구의 목적은 경호경비조직의 멘토링기능이 경력개발 및 조직유효성에 미치는 영향을 규명하는데 있다. 이 연구는 2010년 3월 서울소재 5개소 경호경비회사의 경호경비원을 모집단으로 설정한 후 유의표집법을 이용하여 최종분석에 이용된 사례 수는 총 227명이다. 설문지의 신뢰도는 Cronbach's ${\alpha}$값이 .667이상으로 나타났다. 결론은 다음과 같다. 첫째, 경호경비조직의 멘토링기능은 경력개발에 영향을 미친다. 즉, 우정 보호, 경력관리, 사회심리, 역할모델 기능이 발휘되면, 혁신적 자기 개발, 전문능력 개발, 정보경쟁력개발은 촉진된다. 둘째, 경호경비조직의 멘토링기능은 조직유효성에 영향을 미친다. 즉, 우정 보호, 경력관리, 사회심리, 역할모델 기능이 발휘되면, 경력만족, 조직몰입, 직무만족은 증가한다. 반면, 사회심리적기능이 발휘되면 이직의도는 감소한다. 셋째, 경호경비조직의 경력개발은 조직유효성에 영향을 미친다. 즉, 혁신적, 전문능력 개발이 촉진되면, 경력만족, 조직몰입, 직무만족은 증가한다. 반면, 정보경쟁력 개발이 촉진될수록 이직의도는 감소한다. 넷째, 멘토링기능은 경력개발 및 조직유효성에 인과적 영향을 미친다. 즉, 멘토링기능은 조직유효성에 직접적으로 영향을 미치지만, 경력개발을 통해서 간접적인 영향을 미친다.

• Imaging Science in Dentistry
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• 제47권2호
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• pp.99-107
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• 2017

Purpose: Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. Materials and Methods: Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. Results: The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. Conclusion: The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.

• 대한전기학회논문지
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• 제35권1호
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• pp.17-25
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• 1986

Discussions on this paper are related to the effects of organic materials to treeing phenomena of low density polyethylene. As additives, 11 kinds of organic compounds are selected by considering the respective features such as melting point, boiling point, electron affinity as well as molecular structure, and then the specimens of low density polyethylene are prepared by blending with 10wt% of the selected additives. For the comparison of effectiveness of treeing resistance and interpretation of the mechanism of compounds as treeing retardants, several investigations such as the tree acceleration test, the prestressed test and the measurement of internally occurred partial discharge are carried out. As the results, meta-Cresol is regard as the most effective retardant among those, and it is supposed that this aromatic compound to be comprised of radical having large electron affinity has strong capability to accept energetic electron to prevent or delay the growth of discharge streamer. Furthermore, by activating partial discharge at the wall of tree pit through the function of trapped electron at this material, the gas pressure in the pit is increased up to prevent the growth of streamer.

• 한국도서관정보학회지
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• 제24권
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• pp.81-106
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• 1996

Without an accurate understanding of information needs of library users, an efficient services can't be implement. And we can expect that there is a difference between query statement and actual information needs of users. It also will occur difference in the process of librarian's interpretation of query statement because of an inaccurate presentation and their different working experiences. It means that there is a communication problems between users and librarians. The purpose of this study is to provide the techniques of face to face communication between users and librarians as a method of efficient library service activities. And focused on the importance of non-language communication. The effectiveness of this study are as follows: 1. With the understanding of information flow, librarians can expand the extent of library services. 2. Knowing that how to communicate with users at the a n.0, ppropriate degree, librarians can improve the communication techniques. 3. Expanding the satisfaction of information services and heitening the reliability of users. 4. From the analysis of user information needs, librarians can convert present system to the proper service-oriented system. 5. Knowing the importance of non-language communication, librarians can improve the service environment.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.427-433
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• 2022

Although the National Intelligence Service Act has been amended considering the growing importance of economic counterintelligence, a clear interpretation of certain provisions and improvement of the effectiveness of economic counterintelligence are required. This article presents some suggestions for regulations on economic counterintelligence. Firstly, the meaning of the term "disturbance of economic order in connection with foreign powers" will become clear by interpreting it with the terms of the Counterintelligence Duty Regulation and by setting categories referring to the U. S. regulations. Secondly, counterintelligence authorities' request for cooperation may be reinforced by amending relevant regulations or by applying a special procedure for the acquisition of data. Finally, strengthened punishment for activities in connection with foreign powers may improve the efficiency of counterintelligence. For these reasons, this paper aims to present a direction for the future, focusing on this new economic counterintelligence.

• Geomechanics and Engineering
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• 제11권1호
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• pp.41-58
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• 2016

This paper focuses on the deformation behavior of tunnels crossing a weak zone in conventional tunneling. A three-dimensional finite element model was adopted that allows realistic modeling of the tunnel excavation and the support installation. Using the 3D FE model, a parametric study was conducted on a number of tunneling cases with emphasis on the spatial characteristics of the weak zone such as the strike and dip angle, and on the initial stress state. The results of the analyses were thoroughly examined so that the three-dimensional tunnel displacements at the tunnel crown and the sidewalls can be related to the spatial characteristic of the weak zone as well as the initial stress state. The results indicate that the effectiveness of the absolute displacement monitoring data as early warning indicators depends strongly on the spatial characteristics of the weak zone. It is also shown that proper interpretation of the absolute monitoring data can provide not only early warning for a weak zone outside the excavation area but also information on the orientation and the extent of the weak zone. Practical implications of the findings are discussed.

• ETRI Journal
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• 제30권1호
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• pp.81-88
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• 2008

The security threat posed by worms has steadily increased in recent years. This paper discusses the application of the optimal and sub-optimal Internet worm control via Pontryagin's maximum principle. To this end, a control variable representing the optimal treatment strategy for infectious hosts is introduced into the two-factor worm model. The numerical optimal control laws are implemented by the multiple shooting method and the sub-optimal solution is computed using genetic algorithms. Simulation results demonstrate the effectiveness of the proposed optimal and sub-optimal strategies. It also provides a theoretical interpretation of the practical experience that the maximum implementation of treatment in the early stage is critically important in controlling outbreaks of Internet worms. Furthermore, our results show that the proposed sub-optimal control can lead to performance close to the optimal control, but with much simpler strategies for long periods of time in practical use.

• 전력전자학회논문지
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• 제3권4호
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• pp.338-345
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• 1998

The mathematical interpretation of a practical sampler which is useful to obtain the small signal models for the peak and average current mode controls is proposed. Due to the difficulties in applying the Shannons sampling theorem to the analysis of sampling effects embedded in the current mode control, several different approaches have been reported. However, these approaches require the information of the inductor current in a discrete expression, which restricts the application of the reported method only to the peak current mode control. In this paper, the mathematical expressions of sampling effects on a current loop which can directly apply the Shannons sampling theorem are newly proposed, and applied to the modeling of the peak current mode control. By the newly derived models of a practial smapler, the models in a discrete time domain and a continuous time domain are obtained. It is expected that the derived models are useful for the control loop design of power supplies. The effectiveness of the derived models are verified through the simulation and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.275-278
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• 1998

The mathematical interpretation of a practical sampler which is useful to obtain the small signal models for the peak and average current mode controls is proposed. Due to the difficulties in applying the Shannon's sampling theorem to the analysis of sampling effects embedded in the current mode control, several different approaches have been reported. However, these approaches require the information of the inductor current in a discrete expression, which restricts the application of the reported method only to the peak current mode control. In this paper, the mathematical expressions of sampling effects on a current loop which can directly apply the Shannon's sampling theorem are newly proposed, and applied to the modeling of the peak current mode control. By the newly derived models of a practical sampler, the models in a discrete time domain and a continuous time domain are obtained. It is expected that the derived models are useful for the control loop design of power supplies. The effectiveness of the derived models are verified through the simulation and experimental results.