• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.374-382
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• 2009

Steam generator(SG) tube, as a barrier isolating primary to the secondary coolant system of nuclear power plants(NPP), must maintain the structural integrity far the public safety and its efficient power generation capacity. And SG tubes bearing defects must be timely detected and taken repair measures if needed. For the accomplishment of these objectives, SG tubes have been periodically examined by eddy current testing(ECT) on the basis of administrative notices and intensified SG management program(SGMP). Stress corrosion cracking(SCC) on the SG tubes is not easily detected and even missed since it has lower signal amplitude and other disturbing factors against its detection. However once SCC is developed, that can cause detrimental affects to the SG tubes due to its rapid propagation rate. Accordingly SCC is categorized as prime damage mechanism challenging the soundness of the SG tubes. In this study, reproduced EDM notch specimens are examined for the detectability and quantitative characterization of the axial ODSCC by +PT MRPC probe, containing pancake, +PT and shielded pancake coils apart in a single plane around the circumference. The results of this study are assumed to be applicable fur providing key information of engineering evaluation of SCC and improvement of confidence level of ECT on SG tubes.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.5
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• pp.349-355
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• 2014

Wall thinning defects can occur in the pressure vessels used in a variety of industries. Such defects are related to the flow velocity. Considering the fact that such vessels constitute up to 70 or 80% of the plant structures in a power plant, it is important to measure internal defects as part of a safety evaluation. In this study, optical measurement were applied in a non-destructive evaluation using shearography to ensure the safety and improve the reliability of a power plant through the non-contact, non-destructive evaluation of pressure vessels. In order to verify whether the pressure vessels contained faults, experimental and analytical investigation were conducted to measure any internal defects and out-of-plane deformation from inner temperature changes and pressure changes in the piping of the circulation system. The most important factors in this research were the thickness, width, and length of a defect. An increase in these could confirm an increase in the deformation. Thus, internal defects in a pressure vessel were measured using shearography, which made it possible to ensure the reliability and integrity of the pipe.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.4
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• pp.287-297
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• 2014

For several decades, many countries operating nuclear power plants have been studying the various disposal alternatives to dispose of the spent nuclear fuel or high-level radioactive waste safely. In this paper, as a direct disposal of spent nuclear fuels for deep geological disposal concept, the rod consolidation from spent fuel assembly for the disposal efficiency was considered and analyzed. To do this, a concept of spent fuel rod consolidation was described and the related concepts of disposal canister and disposal system were reviewed. With these concepts, several thermal analyses were carried out to determine whether the most important requirement of the temperature limit for a buffer material was satisfiedin designing an engineered barrier of a deep geological disposal system. Based on the results of thermal analyses, the deposition hole distance, disposal tunnel spacing and heat release area of a disposal canister were reviewed. And the unit disposal areas for each case were calculated and the disposal efficiencies were evaluated. This evaluation showed that the rod consolidation of spent nuclear fuel had no advantages in terms of disposal efficiency. In addition, the cooling time of spent nuclear fuels from nuclear power plant were reviewed. It showed that the disposal efficiency for the consolidated spent fuel rods could be improved in the case that cooling time was 70 years or more. But, the integrity of fuels and other conditions due to the longer term storage before disposal should be analyzed.

• The Journal of the Acoustical Society of Korea
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• v.15 no.6
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• pp.81-89
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• 1996

It is very important for ultrasonic test method to evaluate the integrity of the class I components in nuclear power plants. However, as the rltrasonic test is affected by internal structures and configurations of test materials, backscattering, that is, time invariant noise is generated in large grain size materials. Due to the above reason, the received signal results in low signal to noise(S/N) ratio. Split spectrum processing(SSP) technique is effective to suppress the grain noise. The conventional SSP technique. however, has been applied to unique algorithm. This paper shows that MPO(minimization and polarity threshold) algorithm which two algorithms are applied simulatancously, was utilized, the signal processing time was shorten by using the new constant-Q SSP with the FIR filter which frequency to bandwidth ratio is constant and the optimum parameters were analysed for the signal processing to longitudinal wave and shear wave with the same requirements of inspection on nuclear power plant site. Moreover, the new ultrasonic test instrument, the reference block of the same product form and material specification, stainless stell test specimens and copper test specimens block of the same fabricated for the application of new SSP technique. As the result of experimental test with new ultrasonic test instrument and test specimens, the signal to noise ratio was improved by appying the new SSP technique.

• Korean Security Journal
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• no.36
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• pp.417-442
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• 2013

This study considers the characteristics of the separation of public and private security service during Koryo dynasty, and compares it with the modern security service. Modern day security service's definition of private and public security service was used to distinguish them. Given the different historical settings, it's difficult to argue that the distinction between public and private service during Koryo dynasty was clear, but it can be said that public security service was centered around palace guard and concerns the activities of protest, and military made for the relationship, and private security service was centered around power of DoBang and includes the activities of malingering, and Byolchogun. During the early days of Koryo, protest, district military and soldiers who stay in the palace were all parts of a palace revolt and this institutional improvement of soldiers who stay in the palace was accomplished during King Seongjong's rule. The tradition of a palace revolt can find its roots in the middle military, and after the unification, a palace revolt was reformed into the king's palace revolt of second and the 6th along the course of establishing the nation's system. All of the changes stem from the reformation for consolidating the royal authority. Gyung Dae Seoung wanted to protect himself and he slept with his army night and days and because of that, group of soldiers was created and it was called DOBANG. Some members were from dobang gyeonryong, The forced were powerful because it was gathered with a warriors with extraordinaire martial arts and competent management. Most of the soldiers followed gyeong dae seung because they believed that he has a strong leadership and loves his people, and had a strong faith in him. However, the general gyeong jang had a belief that politics must be reverted to the previous so the relationships between jungbang wasn't smooth. Because of the economic operational problems, due to fraud committed by the mens under his command failed to maintain integrity and was criticised.The misconception also fed up with the emperor and the deepening relationships between the soldiers, his dobang was dismantled. After he took over the dobang, for his personal safety and to strengthen his position he compensated gyeon dae seong's dobang and developed the organization. In the process of extending the dobang Choi chung heon recruited many talented people to strengthen the military base, and also accepted the advice and expanded the power of Dobang. Choi Chung Heon thus consolidated his political gains by weakening the power of the king's army and adjusting the myth, which could've threatened his regime, and this was called Dobang number 6th. Dobang number six got even more powerful by his son named Choi woo, and after ruling, he expanded into a room, and a substantial reorganization of Dobang was developed. And then the creation of yabyeolcho also showed the effect to prevent the crisis. Although the palace guards who were public security service of Koryo Dynasty was still maintained during the military rule era when the royal authority was incapacitated, it was only maintained to have a symbolic meaning as the actual authority including military power was with Choi, the master of Dobang, private security service group. Likewise, during the rule of Choi, private securty service could reign over public security service, and the noteworthy characteristic of Dobang is that it assisted the private soldier groups to seize the military power by reorganizing and modifying military system. Although both differences and similarities can be found when comparing the guards of Koryo Dynasty with those of contemporary society, they have a similarity in terms of the essence of guards that they guarantee the safety of their clients. As for differences, the royalty of Koryo Dynasty and the pursuit of profit of contemporary society are in contrast, and contemporary guards can be seen as the fulfillment of responsibility and duty by free will, whereas guards of Koryo Dynasty were ruled with military coercion.

• Korean Journal of Legislative Studies
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• v.22 no.2
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• pp.113-156
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• 2016

Media scholars take a lion stake in power circle. Not only do they take a part in media policies but seize prestigious positions like board members in Korea Communication Commission(KCC). Unfortunately, though, little has been known about who they are, what qualifications they have, and whether they meet public interests. This paper attempts to unveil the mechanism of those politicized intellectuals who are specialized on the media. Two categories divided into 'representative' and 'expertise' are employed for this purpose. On the one hand, the representative means the degree of committment into such public services as participation in conferences or non-profit organizations. On the other hand, the number of research articles, books and projects belong to the expertise. Evaluation levels consist of 'excellence, good and average' were allocated to those scholars who are(were) in 'Power Hole,' where decision makings come into being. Some interesting observations were made though this study. First of all, such criteria as representative and expertise vaguely suggested by the laws were hardly fit into those intellectuals, Rarely did they commit into public service let alone showing vigilance in academic activities. Secondly, both ideological loyalty and political activities in line with the government had much to do with taking such positions. Thirdly, not surprisingly, it showed that to graduate from Seoul National University and have Ph.D. degree from U.S.A. was one of the most essential factors. In final, most of them were very good at taking advantage of the press in way of boosting their publicity. To attend at policy making processes either in form of board members or advisers is inevitable for media experts. However, as shown in this study, such qualification of public service and academic eagerness shouldn't be underestimated. Academic integrity not selling intelligence solely for private interests needs to be protected as well. The authors hope this study to provide a valuable opportunity to establish a kind of ethical standards in participating into politics.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.6 s.52
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• pp.137-145
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• 2006

Recently, the interests in structural monitoring of civil infrastructures are increased. Especially, as the civil infrastructures such as bridges, tunnels and buildings become large-scale, it is necessary to monitor and maintain the safety state of the structures, which requires smart systems that can supply long-term monitoring during the service time of the structures. In this paper, we investigated the possibilities of fiber optic sensor application to the various structures. We investigate the possibility of using fiber optic Bragg grating sensors to joint structure. The sensors show good response to the structural behavior of the joint while electric gauges lack of sensitivity, durability and long term stability for continuous monitoring. We also apply fiber optic structural monitoring to the composite repaired concrete beam structure. Peel-out effects is detected with optical fiber Bragg grating sensors and the strain difference between main structure and repaired carbon sheets is observed when they separate each other. The real field test was performed to verify the behaviors of fiber Bragg grating sensors attached to the containment structure in Uljin nuclear power plant in Korea as a part of structural integrity test which demonstrates that the structural response of the non-prototype primary containment structures. The optical fiber Bragg grating sensor smart system which is the probable means for long term assessments can be applicable to monitoring of structural members in various civil infrastructures.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.1
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• pp.107-116
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• 2009

Quantum-dot Cellular Automata (QCA) is one of the most promising next generation nanoelectronic devices which will inherit the throne of CMOS which is the domineering implementation technology for large scale low power digital systems. In late 1990s, the basic operations of the QCA cell were already demonstrated on a hardware implementation. Also, design tools and simulators were developed. Nevertheless, its design technology is not quite ready for ultra large scale designs. This paper proposes a new approach which enables the QCA designs to inherit the verification methodologies and tools of CMOS designs, as well. First, a set of disciplinary rules strictly restrict the cell arrangement not to deviate from the predefined structures but to guarantee the deterministic digital behaviors is proposed. After the gate and interconnect structures of. the QCA design are identified, the signal integrity requirements including the input path balancing of majority gates, and the prevention of the noise amplification are checked. And then the digital logic is extracted and stored in the OpenAccess common engineering database which provides a connection to a large pool of CMOS design verification tools. Towards validating the proposed approach, we designed a 2-bit adder, a bit-serial adder, and an ALU bit-slice. For each design, the digital logic is extracted, translated into the Verilog net list, and then simulated using a commercial software.

• Management & Information Systems Review
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• v.39 no.2
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• pp.113-126
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• 2020

This study suggested implications by dividing the concept of brand origin into national image and manufacturing capacity image, verifying the direct impact of these variables on brand trust and brand loyalty, and verifying the difference between products with the effect on brand trust of brand origin, which is the result of verification. The specific implications of this paper are as follows. First, brand origin does not directly affect brand loyalty, but it can have a direct impact on the preceding variable, brand loyalty. This study may conclude that it is desirable to define the factors that affect the purchase selection indirectly through the assessment of product properties or positive effects on brand image rather than having a direct impact on product purchase or selection. Second, the difference in brand origin influence by product characteristics was very evident. Past studies were limited to a few products, so pan-product testing was not conducted, and the empirical power was judged to be limited, so this study included a variety of products and tried to detect differences between products through actual empirical research. Involvement and self-congruity have been presented with results that can be judged as important variables for brand origin to affect brand performance and variables. Looking at the role of the brand origin for each product characteristic by distinguishing between product characteristics and whether or not products related to quality, history, authenticity, etc., the product recognized as high quality and the product recognized as having high integrity showed higher effect of the brand origin, but history was a product characteristic that did not show the effect of the brand origin.

• Strategy21
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• s.33
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• pp.5-36
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• 2014

This article aims to analyze the diplomatic challenges currently facing China as well as the foreign policy the Xi Jinping administration is adopting to address them. With these purposes in mind, it will look into three areas: first, diplomatic tasks confronting the Xi leadership; second, foreign policy that the Xi administration has implemented since the 18th Party Congress in 2012; and third, the prospects for China's foreign policy under the Xi leadership. As the Xi Jinping administration entered into office, it has encountered two major diplomatic challenges. One is the searching for a new foreign policy, and the other the restructuring of the existing foreign affairs and national security systems. The Xi administration, during its first year in office, has responded actively to tackle these issues. To begin with, it has attempted to make some adjustments on foreign policy while maintaining the Deng Xiaoping line of foreign policy. One of these modifications is placing emphasis on national "core interest," as illustrated by changes in guideline for maritime conflicts, pushing for building maritime power, and proclamation of Air Defense Identification Zone in the East China Sea. Second is the decision on the new guideline for peripheral diplomacy. That is, the administration regarded creating peaceful and stable environments to realize "Chinese Dream" as an important goal of foreign policy, and proposed such new guiding ideology as "familiarity, integrity, benefit, and accommodation." In additoin, the Xi administration restructured the existing foreign affairs and national security systems. Establishing the Central State Security Committee and the Internet Leading Small Group (LSG) are cases in point. As comprehensive organizations for policy coordination that encompass party, government, and military, the two LSGs are in charge of enacting related policies and fine-tuning policy implementation, based upon leadership consisting of chiefs of each relevant organs. Moreover, since Xi himself became the chief of these two newly-found organs, the conditions under which these LSGs could demonstrate unified leadership and adjusting role in its implementation of military, diplomatic, and security policies were developed. The future Chinese diplomacy will be characterized with three main trends. First, peripheral diplomacy will be reinforced. The peripheral diplomacy has become far more important since the Work Conference on Peripheral Diplomacy in October 2013. Second, economic diplomacy will be strengthened with an eye on reducing the "China Threat Theory," which still exists in Asia. Third, the policies to isolate the Philippines and Japan will continue in regard to maritime disputes. All in all, Chinese diplomacy in the Xi Jinping era is likely to feature practical diplomacy which combines both hard and soft approaches to best realize Chinese national interest.