• Nuclear Engineering and Technology
• /
• v.46 no.2
• /
• pp.207-216
• /
• 2014

This paper revisits the Fukushima accident to draw lessons in the aspect of nuclear safety considering the fact that the Fukushima accident resulted in core damage for three nuclear power plants simultaneously and that there is a high possibility of a failure of the integrity of reactor vessel and primary containment vessel. A brief review on the accident progression at Fukushima nuclear power plants is discussed to highlight the nature and characteristic of the event. As the severe accident management measures at the Fukushima Daiich nuclear power plants seem to be not fully effective, limitations of current severe accident management strategy are discussed to identify the areas for the potential improvements including core cooling strategy, containment venting, hydrogen control, depressurization of primary system, and proper indication of event progression. The gap between the Fukushima accident event progression and current understanding of severe accident phenomenology including the core damage, reactor vessel failure, containment failure, and hydrogen explosion are discussed. Adequacy of current safety goals are also discussed in view of the socio-economic impact of the Fukushima accident. As a conclusion, it is suggested that an investigation on a coherent integrated safety principle for the severe accident and development of innovative mitigation features is necessary for robust and resilient nuclear power system.

• Nuclear Engineering and Technology
• /
• v.49 no.8
• /
• pp.1589-1599
• /
• 2017

Field programmable gate arrays (FPGAs) are getting more attention in safety-related and safety-critical application development of nuclear power plant instrumentation and control systems. The high logic density and advancements in architectural features make static random access memory (SRAM)-based FPGAs suitable for complex design implementations. Devices deployed in the nuclear environment face radiation particle strike that causes transient and permanent failures. The major reasons for failures are total ionization dose effects, displacement damage dose effects, and single event effects. Different from the case of space applications, soft errors are the major concern in terrestrial applications. In this article, a review of radiation effects on FPGAs is presented, especially soft errors in SRAM-based FPGAs. Single event upset (SEU) shows a high probability of error in the dependable application development in FPGAs. This survey covers the main sources of radiation and its effects on FPGAs, with emphasis on SEUs as well as on the measurement of radiation upset sensitivity and irradiation experimental results at various facilities. This article also presents a comparison between the major SEU mitigation techniques in the configuration memory and user logics of SRAM-based FPGAs.

• STI Policy Review
• /
• v.4 no.1
• /
• pp.14-26
• /
• 2013

The $1^{st}$ National Plan for Aging Society with Low Fertility, which the Korean government announced in 2006, caused the gradual increase of R&D investment in order to prepare for an aging society in Korea. This study explores if the directions and strategies of R&D projects related to aging are suitable to improve the quality of life for elderly people and establish a sustainable aging society by analyzing the features of R&D investment from 2004 to 2010. The results show that most R&D projects conducted by departments focus on the development of assistive devices for the elderly to support everyday lives. The Korean government's R&D policy to prepare for an aging society is based on the narrow interpretation of Quality of Life (QoL) in an aging society that tries to resolve the socioeconomic problems of the elderly; however, the policies have ignored the independence of active elderly individuals and the social integration of the young and elderly generations. The research shows that a paradigm shift is required from a 'Senior' to 'Aging Society' because almost 1/3 of the Korean population is over 65 years old and the expansion of the research embraces from assistive technologies for the elderly to the design of social infrastructure such as transportation, education and work.

• Information Systems Review
• /
• v.6 no.2
• /
• pp.161-179
• /
• 2004

The purpose of this study is to suggest practical experience to develop small sized e-Learning system. The system is designed to help lecturers can arrange interface, organize contents, submit examinations and assess learner's score with no professional computing skills. The system has three advantages. First, it reduced implementation period through the use of GUI. Second, it is ordered to be personalized to construct format of the whole interface. Third, it has operational convenience which can be implemented on PC based system. These personalized features are enabling Learning on Demand. Also, there is comparatively low cost and high effectiveness on e-Learning implementation which facilitating quick adoption of e-Learning in its lectures.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.10 no.1
• /
• pp.47-53
• /
• 2014

LTE-Advanced is the evolved version of LTE which is currently in progress at the 3GPP. At present, as the number of smart phone users is rapidly increasing, the demand for ever more capacity is driven largely by video usage and high quality data communication and so on, this let more researchers study about LTE-A all over the world. LTE-A aims to achieve improved service and communication quality over 3G system at the aspect of throughput, peak data rate, latency, and spectral efficiency. Among various features in LTE-A, the multi-user MIMO(MU-MIMO), in which the base station transmits several streams to multiple receivers, has expected to give better quality for system. In this paper, we investigate performances of various types of downlink receivers with fixed number of antennas. we first review the development process from LTE to LTE-A. Second we introduce TM9 which is adopted in Rel.10 for MU-MIMO system, including the MU-MIMO system model and the explanation on the algorithm used in system. We also have brief introduction about sub-blocking in turbo decoding, finally we compare the performance between the uncoded case and coded case which is using turbo encoding.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.72
• /
• pp.161-183
• /
• 2016

This study looked at the Korea enterprise in China market practices and strategies in accordance with the Korea China FTA macroscopically. And the systematic localization in the mid-to long-term decisions necessary for successful, it is important to the local economy by contributing to strategic social contribution activities also ensure the reliability of consumers. In addition to factors that may enjoy various benefits from an Korea China FTA strategy it is also needed to maximize the additional benefits of the FTA signed by Korea before. In particular, this strategy requires that the biggest benefits of FTA, that determine the tariff cuts by FTA partners to take advantage of it. In addition, the strategy that should be taken in advance to prevent any unnecessary risks through the recent rapid and thorough understanding of the appropriate response, Chinese, Chinese culture on O2O retail market. It is considered that the Korea China FTA requires multidimensional efforts with seeking a comprehensive and affordable countermeasures in order to act as an important factor for Korea market companies, government, companies and academia at the same time. In particular, the idea to carefully look at the various features with the Chinese consumer market will be a very important point.

• The Korean Journal of Pain
• /
• v.25 no.1
• /
• pp.28-32
• /
• 2012

Background: Primary hyperhidrosis is a disorder of excessive sweating, which shares several features with anxiety disorders and has a negative impact on a patient's quality of life. Oral glycopyrrolate is one of the treatments available. There are a few published studies on the use of glycopyrrolate given orally in the treatment of hyperhidrosis. Methods: Thies is study was a review of case notes in a series of 36 patients with primary hyperhidrosis. We made a comparison between the Keller's scale score of a pre-glycopyrrolate medication group and the Keller's scale score f a post-glycopyrrolate medication group. The Milanez de Campos score, Short Form_36 (SF-36) score, Beck Depression Inventory (BDI) score, Beck Anxiety Inventory (BAI) score, and autonomic nervous system (ANS) scale score were also compared between the two groups. Results: In the post-glycopyrrolate medication group, there were declines in Keller's scale, and Milanez de Campos scale score and BAI score (P < 0.001). In addition, there were increases in SF_36 score in the post-glycopyrrolate medication group (P = 0.03) However, no changes were seen in, BDI score and ANS score in the post-glycopyrrolate medication group (P < 0.001). Conclusions: Glycopyrrolate is an effective initial method of treating primary hyperhidrosis that, reduces anxiety and improve patients' quality of life.

• Restorative Dentistry and Endodontics
• /
• v.41 no.4
• /
• pp.322-331
• /
• 2016

Variation in the root and canal morphology of the maxillary first molars is quite common. The most common configuration is 3 roots and 3 or 4 canals. Nonetheless, other possibilities still exist. The presence of an additional palatal root is rather uncommon and has been reported to have an incidence of 0.06 - 1.6% in varying populations studied. Whenever two palatal roots exist, one of them is the normal palatal root, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis) or distolingually (radix distolingualis). This case report describes successful endodontic treatment of a maxillary first molar with radix mesiolingualis and radix distolingualis. Identification of this variation was done through clinical examination along with the aid of multiangled radiographs, and an accurate assessment of this morphology was made with the help of a cone-beam computed tomography imaging. In addition to the literature review, this article also discusses the epidemiology, classifications, morphometric features, guidelines for diagnosis, and endodontic management of a maxillary first molar with extra-palatal root.

• English Language & Literature Teaching
• /
• v.15 no.4
• /
• pp.55-74
• /
• 2009

Although a considerable amount of research on discourse signaling cues has been conducted in reading, little attention has been paid to such cues in the area of listening. Moreover, despite the solid evidence showing that cues have beneficial effects for reading comprehension, L2 listening research has produced mixed findings about the role of cues. Such discrepancies among these findings might be due in part to inadequate research methodologies as well as the idiosyncratic features of their experimental designs. However, no study, to date, has thoroughly examined the research designs of listening comprehension studies on cues. Consequently, this study critically evaluates the present state of research designs and reporting practices of studies investigating the role of cues in listening comprehension. The present study aims to provide insights into areas that require empirical attention and systematic investigation. It also seeks to encourage improved and refined research practices for future studies. This paper is organized as follows: It will first critically review the empirical findings regarding cues in the area of L1 listening comprehension. Second, it will present a critical evaluation of L2 listening studies on cues. Finally, it will address the major research design issues of currently available listening studies and provide suggestions for improvement in future research.

• Journal of Korean Society of Archives and Records Management
• /
• v.12 no.2
• /
• pp.51-70
• /
• 2012

This study is aimed to evaluate the national archives websites and to propose improvement schemes for National Archives of Korea(NAK)'s website. As the first step to develop the evaluation indicators, this study investigated the roles of national archives and features of national archives websites through literature review. Second, it developed the evaluation indicators for national archives websites to evaluate the websites on the basis of previous studies. The evaluation indicators are composed of 3 evaluation areas, 10 evaluation items, and 42 evaluation questions. Third, evaluation was conducted to examine the present state of national archives websites in United Kingdom, United States, Australia, Canada and Korea.