• Investigative Magnetic Resonance Imaging
• /
• v.16 no.1
• /
• pp.1-5
• /
• 2012

Breast MRI is the most accurate adjunctive to the mammography for the screening of breast cancer. Despite lack of randomized controlled trials on the effectiveness of MRI screening, it is now recommended for the women at high risk for breast cancer by the American Cancer Society and the National Comprehensive Cancer Network based on several prospective observational studies. In Korea, a retrospective study reported that preoperative MRI screening of the contralateral breast in women with unilateral breast cancer was associated with reduced metachronous cancer incidence. To introduce breast MRI as a supplemental modality to screening mammography in Korea, standardization and education of interpretation, establishment of MR-guided biopsy and adequate indication, and evaluation of cost-effectiveness and should be preceded.

• The Journal of the Korea Contents Association
• /
• v.11 no.6
• /
• pp.326-336
• /
• 2011

The Purpose of this study was to examine effects of mentoring function on career development and organizational effectiveness in private security service organization. Example number used on interpretation finally using purposive sampling method after this study establishes 5 places private security service company's security guard by population in Seoul on March, 2010 is total 227 people. Reliability of questionnaire appeared Cronbach's ${\alpha}$ value more than .667. Conclusions that appears in this study is as following. First, private security service organization's Mentoring function affects in career development. That is, if friendship, patronage, career management, society mind, and role model are mobilized, innovative own development, special capacity development, and information competitive power development are helped. Second, private security service organization's Mentoring function affects in organization effectiveness. If friendship, patronage, career management, society mind, and role model are mobilized, career satisfaction, organization immersion, and job satisfaction increase. On the other hand, change of jobs intention decreases if function of society mind is mobilized. Third, private security service organization's career development affects in organization effectiveness. If reform and special capacity development are helped, career satisfaction, organization immersion, and job satisfaction increase. While change of jobs intention decreases as development of information competition is helped. Fourth, Mentoring function exerts influence of causality on career development and organization effectiveness. That is, Mentoring exerts direct influence on organization effectiveness, but it exerts indirect effect through career development.

• Imaging Science in Dentistry
• /
• v.47 no.2
• /
• pp.99-107
• /
• 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.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.1
• /
• pp.17-25
• /
• 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.

• Journal of Korean Library and Information Science Society
• /
• v.24
• /
• pp.81-106
• /
• 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
• /
• v.10 no.4
• /
• pp.427-433
• /
• 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
• /
• v.11 no.1
• /
• pp.41-58
• /
• 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
• /
• v.30 no.1
• /
• pp.81-88
• /
• 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.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.3 no.4
• /
• pp.338-345
• /
• 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.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.275-278
• /
• 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.