• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1411-1417
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• 2010

CFRP (Carbon Fiber Reinforced Plastic) has received considerable attention in various fields as a structural material, because of its high specific strength, high specific stiffness, excellent design flexibility, favorable chemical properties, etc. Most products consisting of several parts are generally assembled by mechanical joining methods (using rivets, bolts, pins, etc.). Holes must be drilled in the parts to be joined, and the strength of the components subjected to static and fatigue loads caused by stress concentration must be decreased. In this study, we experimentally evaluated the variation in the residual strength of a holenotched CFRP plate subjected to fatigue load. We repeatedly subjected the hole-notched specimen to fatigue load for a certain number of cycles, and then we investigated the residual strength of the hole-notched specimen by performing the fracture test. From the results of the test, we can observe the initiation of a directional crack caused by the applied fatigue load. Further, we observed that the residual strength increases with a decrease in the notch effect due to this crack. It was evaluated that the residual strength increases to a certain level and subsequently decreases. This variation in the residual strength was represented by a simple equation by using a model of the decrease in residual strength for plain plate, which was developed by Reifsnider and a stress redistribution model for hole-notched plate, which was developed by Yip.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.9
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• pp.459-466
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• 2007

TCP/IP processing imposes a heavy load on the host CPU when it is processed by the host CPU on a very high-speed network. Recently the TCP/IP Offload Engine (TOE), which processes TCP/IP on a network adapter instead of the host CPU, has become an attractive solution to reduce the load in the host CPU. There have been two approaches to implement TOE. One is the software TOE in which TCP/IP is processed by an embedded processor and the other is the hardware TOE in which TCP/IP is processed by a dedicated ASIC. The software TOE has poor performance and the hardware TOE is neither flexible nor expandable enough to add new features. In this paper we designed and implemented a hybrid TOE architecture, in which TCP/IP is processed by cooperation of hardware and software, based on an FPGA that has two embedded processor cores. The hybrid TOE can have high performance by processing time-critical operations such as making and processing data packets in hardware. The software based on the embedded Linux performs operations that are not time-critical such as connection establishment, flow control and congestions, thus the hybrid TOE can have enough flexibility and expandability. To improve the performance of the hybrid TOE, we developed a hardware-based transmission/reception accelerator that processes important operations such as creating data packets. In the experiments the hybrid TOE shows the minimum latency of about $19{\mu}s$. The CPU utilization of the hybrid TOE is below 6 % and the maximum bandwidth of the hybrid TOE is about 675 Mbps.

• Advances in nano research
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• v.8 no.4
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• pp.323-333
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• 2020

In recent years, there has been an upsurge for the usage of buckling restrained braces (BRB) rather than ordinary braces, as they have evidently performed better. If the overall brace buckling is ignored, BRBs are proven to have higher energy absorption capacity and flexibility. This article aims to deliberate an economically efficient yet adequate type of all-steel BRB, comprised of the main components as in traditional ones, such as : (1) a steel core that holds all axial forces and (2) a steel restrainer tube that hinders buckling to occurr in the core; there is a more practical detailing in the BRB system due to the elimination of a filling mortar. An investigation has been conducted for the proposed rectangular-tube core BRB and it is hysteric behavioral results have been compared to previous researches conducted on a structure containing a similar plate core profile that has the same cross-sectional area in its core. A loss of strength is known to occur in the BRB when the limiting condition of local buckling is not satisfied, thus causing instability. This typically occurs when the thickness of the restrainer tube's wall is smaller than the cross-sectional area of the core plate or its width. In this study, a parametric investigation for BRBs with different formations has been performed to verify the effect of the design parameters such as different core section profiles, restraining member width to thickness ratio and relative cross-sectional area of the core to restrainer, on buckling load evaluation. The proposed BRB investigation results have also been presented and compared to past BRB researches with a plate profile as the core section, and the advantages and disadvantages of this configuration have been discussed, and it is concluded that BRBs with tubular core section exhibit a better seismic performance than the ones with a plate core profile.

• Journal of Korean Library and Information Science Society
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• v.8
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• pp.127-154
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• 1981

Today's complicated society with a rapid change needs more objective and accurate data for the better managerical decisions and the prospect for the future other than the intuition or subjective experience by men themselves. These data can't be extracted without the analysis of actual data by a n.0, pplying any of mathematical techniques. One of these mathematical techniques, called bibliometrics has been newly developed in the field of library and information science to extract the objective data for the better services through the library operations. The Beadford's Law, one important law in bibliometrics has provided rather scientific and objective basis on the more valid building of library collection within the constraints of budget. The purpose of the study is to investigate the theory of the Bradford's Law, to clarify the possible areas of its a n.0, pplication, and to discern some problems in doing so. The results of the study can be summarized as follows; (1) There is certain difference between the graphical formulation and verbal formulation of Bradford's Law. But this law is very useful for the field of library and information science, owing to the flexibility of the a n.0, pplication of the law in the field. (2) The minimal nucleus can consist of a single periodical only if j, the number of relevant papers in the most productive journals is greater than Z/2. On the other hand, if j is less than or equal to Z/2, then the minimal nucleus will consist of 2 or more periodicals. (3) It is possible to design the most compact selection of scientific periodicals covering any specified percentage P among the total periodicals by using the formulation, log n=Plog N+(1-P)logs, or Nlog N/s=P center dot N log N/s. (4) If there is need to provide all the articles needed by users the given budget, the library can purchase the proper number of journals, by using the formulation, f center dot AN=An+PN (log N/s-logn/s). (5) In the building of the library collection based on the decreasing ratio of use, the library can subscribe to the proper number of journals according to the satisfactory degree of the need, by using the formulation, f=Nu+uNlogN/S-uNlogn/s / nNlogN/s = 1+logN/m /logN/s (6) If the order of valuable journals is decided according to the frequency of being cited, the order can't always represent the value. (7) The evaluation criteria for the journals with high value, but less cited should be made a further study.

• Journal of Distribution Science
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• v.12 no.2
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• pp.95-103
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• 2014

Purpose - Korea has a better geographical location than other nations in the Northeast Asian region. This means that Korea has an opportunity to become the center of international physical distribution in Northeast Asia. Korea should take advantage of this opportunity by exploring appropriate strategies to achieve this goal, assuming government willingness, with a view to capitalizing on the geographical advantage of the Korean peninsula and constructing a comprehensive physical distribution network system. If we prepare for this scenario, Korea could become the center of international physical distribution in Northeast Asia. Research design, data, and methodology - This study has the purpose of determining how shipping companies form partnerships with third-party logistics providers, and the relevant implications. The survey methods used were personal interview and a questionnaire distributed through e-mail, fax, mail, and telephone. A total of 600 questionnaires were distributed, out of which 285 were returned. Of the collected questionnaires, 10 were excluded because of insufficient content, leaving 275 to be used in the study as available valid samples. The data that was collected from these samples was analyzed using the data coating process and by employing a statistical package program. Results - Flexible policies, administration, and systems will be needed to create better business practices. In this dissertation, first and foremost, the results reveal that in order to become the center of Northeast Asian logistics, Korea must transition into a new paradigm based on the current economic and social systems that have stemmed from bureaucracy, inflexibility, chauvinism, and egalitarianism. Flexible policies, administration, and systems will be required to create better business practices. Domestic logistics corporations need to occupy a strategic logistics hub, create a logistics network, and activate value-added logistics business strategies by ensuring significant manpower and by building a logistics information system to strengthen their competitive edge, creating an improved system. Conclusions - In this dissertation, first and foremost, we point out that in order to become a center of North East Logistics, Korea should change to a new paradigm from the old one based on current economic and social systems that have stemmed from bureaucracy, inflexibility, chauvinism, and egalitarianism. More reasonable business laws, systems, and policies based on market-driven flexibility and transparency should be created. Moreover, social norms and rules should be reasonably established, to accomplish political and social security. Korea has to cultivate a culture of tolerance for foreign companies. This involves a change of paradigm for the development of the capital city and satellite cities. It will take a powerful task force or organization to plan and execute the vision that aims to meet these needs, accomplish the necessary goals, use the appropriate system effectively, and make Korea a key country in the field of Northeast Asian logistics.

• The Journal of Industrial Distribution & Business
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• v.11 no.6
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• pp.29-39
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• 2020

Purpose: The purpose of this study is, in the situation where rapid response to the rapidly changing environment is required due to the development of the fourth industrial revolution such as artificial intelligence, virtual reality, and the internet of things, robotics, big data, additive manufacturing, bio-health, sharing economy and in the organizational culture aspiring toward the innovation of a major company, small business and a public institution, to analyze what influence a job-engagement and stress make, and what influence individual's self-efficacy as a moderator mediator makes, and to offer basic data for improving job-engagement and lowering job-stress. Research design, data, and methodology: For doing this, the literature and the empirical studies were combined. Deriving innovation-oriented organizational culture as factors affecting the job engagement and job stress through the literature, and have established hypotheses to verify them. We have collected data of 281 from ex,ecutives and staff-members working in areas including major company, small business and officials (the central government, a local public service, the prosecution, the police, and school). And these data were analyzed by SPSS 23 version. Results: Based on these data, the results of analysis were as follows; First, the innovation-oriented organizational culture which was recognized by organizational members had effect on job-stress. Second, the innovation-oriented organizational culture which was recognized by organizational members influenced job-stress. Third, in the relationship between the innovation-oriented organizational culture and job-engagement, self-efficacy did not influenced job-engagement. Finally, in the relationship between the innovation-oriented organizational culture and job-stress, self-efficacy influenced job-stress. Conclusions: Innovation-oriented organizational culture places importance on the organization's adaptability and flexibility in the external environment, so companies need to establish an innovation-oriented organizational culture favorable to achieving survival and successful innovation, and to develop and disseminate programs of positive and continuous organizations to improve task enthusiasm, reduce task stress, and enhance organizational performance. In the future, it will be necessary to verify the effectiveness of various organizational culture types through comparative analysis with companies that actively maintain an innovation-oriented organizational culture (Google, Kakao, etc.) and companies that prefer hierarchy-oriented organizational culture, relationship-oriented organizational culture, and market-oriented organizational culture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.47-58
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• 2017

This study examined the effects of elderly people's frail prevention program performed in a senior center located in J-si. The most interesting were the effects on the subjective health status, depression, physical fitness, and quality of life for the senior center participation of the elderly. The nonequivalent control group pre-post-test design was employed. A total of 43 people living in J-si were assigned to either the experimental group (n=22) or control group (n=21). The experimental group was provided with the 8-weeks frail elderly prevention program from September 1 to October 16 in 2015. The data were analyzed with SPSS/WIN 21.0 using descriptive statistics, $x^2-test$, Fisher's exact test, and t-test. The results indicated a significant difference between the experimental group and control group with respect to the scores of the subjective health status (t=-0.35, p=.024), depression (t=2.76, p=.035), physical fitness, including right grip strength (t=-3.10, p=.004) and flexibility of the waist (t=-2.13, p=.039), and the quality of life (t=4.36, p<.001). In conclusion, an elderly people's frail prevention program has a significant effect on the change in subjective health status, depression physical fitness, quality of life, and self-care behavior for senior center participation.

• Journal of the Korean Society for Railway
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• v.15 no.1
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• pp.42-47
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• 2012

There are ATC (Automatic Train Control), ATP (Automatic Train Protection), ATS (Automatic Train Stop) and ATO (Automatic Train Operation) etc. in train control systems. As various train control systems are installed according to sections, on-board signaling systems are installed to apply to the section. Hence, operation flexibility of trains is decreased. In other words, when trains are operated in the section where other train control systems are used, the on-board signaling systems are changed. Recently, a study on the combined on-board signaling system has been researched to solve this problem. The combined on-board signaling system consists of ATC, ATP and ATS device. Because the train control systems are vital, it needs to design the combined on-board signaling system by using k out of n system. In this paper, when k out of n system is applied in the combined on-board signaling system, the reliability and loss cost are analyzed by using failure rate in each device. Hence, the ideal number of systems is presented according to the number of outputs.

• Journal of the Korean Society of Costume
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• v.44
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• pp.181-199
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• 1999

The industry of modern clothing has deviated from the overflow of commercialism and the standardization and nowadays is going toward pursuing art, creativity, and high added value. This trend brings the return of the natural materials from the synthetic textiles and increases the value of old and handmade fabrics. Finally, the handmade-paper, which is a natural material, comes to be reconsidered as a new material for the clothing. Therefore, as the natural materials and the manufacture of handmade clothing are rising again, the qualitative improvement and globalization of clothing industry should be first realized through the developments of creative and various clothing materials and new expressing techniques. The above investigation and study have been synthesized and analyzed as follows: First, through the study on the origin of the paper clothing, its historical background and the process of its development, we've learned these two facts following : the paper clothing of the East in the past mostly had practiced meanings. On the other hand, in the West it had meanings which were raised the artist's emotions and beauty-consciousness to the artistic level by the various kinds of expressing methods. Second, handmade-paper was manufactured by the embedding method, which mixed mulberry pulp, gauze, corn, hair, sisal, silk and so on. It was found that handmade-paper had the affluent and proper texture as the clothing material and was be able to control the clarity through the variation of thickness. It was also confirmed that the creative and original texture with hand-worked molding beauty was obtained by the use of handmade-paper. Third, when the handmade-paper is used, the molding beauty of plane, relievo, and solid can be freely pursued, and various and effective molding conformation can be constructed by the effect of superposition and repetition. Also, because the maximum discretion from the various optional manufacturing methods is allowed, the molding beauty can be maximized when the clothes are manufactured with handmade-paper. Fourth, the gauze with strong drape was combined to overcome the stiffness and the tearing of the paper. As a result, the durability and the wearability of the paper were strengthened and thus the thus the applications as the clothing material were enlarged. In conclusion, in order to enhance the value, creativity, practicality, and artistic sense of the design for modern clothing, the clothes made of handmade-paper should be more studied. Moreover, for the generalization of paper clothes, the studies on the development of practical paper with paper with water resistance, post-treatment after dyeing, flexibility, and durability should be done. I really hope that this study will be the motive to provoke the possibility of handmade-paper as new clothing material in not only practical sense but also artistic sense.

• Journal of the Korean School Mathematics Society
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• v.7 no.2
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• pp.1-20
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• 2004

The purpose of this study is to suggest the new way about performance assessment through analyzing about what changes are occurred on mathematical attitude and interest by performance assessment as comparing and analyzing the effect on learners' mathematical preferences and learning attitudes through the application of teaching and evaluating model utilizing portfolio products using mathematical history which is one of the various ways of performance assessment. That can satisfy the feature of performance assessment that realizes instruction and assessment simultaneously on the first grade at high school. Also, it can reduce the teachers' works, search the potential ability of students, realize level type curriculum, and draw out the learners' interests because it is a self-leading instruction that consists of student-centered learning. For the purpose of this study, the role of mathematical history and its advantage and the way of utilizing it in mathematical history by referring to sundry records were studied. Evaluation, the way of performance assessment and scoring were also considered to design portfolio teaching and evaluating model using mathematical history. To solve the another tasks for this study, mathematical preference factors and mathematical learning attitude factors are used. Mathematical preference factors divide into confidence, flexibility, will, curiosity, reflection, and value and then make 4 questions each factor. And mathematical learning attitude factors divide into self-esteem, attitude, and learning habit and then make 10 questions each factor. These factors need to be reorganized the materials which are made by Korean Education Development Institute(1992) to be agreed with the purpose of this study.