• Journal of Digital Contents Society
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• v.17 no.3
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• pp.181-188
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• 2016

Video streaming traffics which are arrived in receiver have irregular traffic patterns by many problems over the network path. Particularly, if these received traffics enter into replay buffer without any operation, the overflow and underflow effects are made according to the buffer status. There was an existing scheme which automatically set up token bucket parameters using the video information file under the assumption of the lossless packet on network. The existing scheme has a problem which can set up the wrong token bucket parameters by the lost packets on the practical networks with video packet loss. Therefore, this paper proposes a new scheme which reset up video file information to correct the wrong token bucket parameters in case of packet loss in practical networks with packet loss. Through the simulation, it was found that the proposed scheme would have better performance than the existing scheme in terms of overflow generation and packet loss.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1083-1095
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• 2016

The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodiumshowed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.39-49
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• 2018

In the satellite operation phase, a ground station should continuously monitor the status of the satellite and sends out a tasking order, and a satellite should transmit data acquired in the space to the Earth. Therefore, the communication between the satellites and the ground stations is essential. However, a satellite and a ground station located in a specific region on Earth can be connected for a limited time because the satellite is continuously orbiting the Earth, and the communication between satellites and ground stations is only possible on a one-to-one basis. That is, one satellite can not communicate with plural ground stations, and one ground station can communicate with plural satellites concurrently. For such reasons, the efficiency of the communication schedule directly affects the utilization of the satellites. Thus, in this research, considering aforementioned unique situations of spacial communication, the mixed integer programming (MIP) model for the optimal communication planning between multiple satellites and multiple ground stations (MS-MG) is proposed. Furthermore, some numerical experiments are performed to verify and validate the mathematical model. The practical example for them is constructed based on the information of existing satellites and ground stations. The communicable time slots between them were obtained by STK (System Tool Kit), which is a well known professional software for space flight simulation. In the MIP model for the MS-MG problems, the objective function is also considered the minimization of communication cost, and ILOG CPLEX software searches the optimal schedule. Furthermore, it is confirmed that this study can be applied to the location selection of the ground stations.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.3
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• pp.361-373
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• 2011

In line with post-1970s industrialization, the manpower shortage in fishing villages has been fueled by rapid desertion; young adults and middle-aged people have tended to avoid fishing by migrating to cities, driving the emergence of a national issue in terms of securing fisheries management succession. For the fisheries industry to maintain competitiveness, we need to cultivate young adults and middle-aged people to be leaders of the domestic fishing industry through promoting inspiration for the fishing industry, teaching fisheries expert knowledge, and fostering the ability to promote business. In addition to safe supply of marine products through continued fisheries operation, securing young and skilful workers is essential in order to promote balance development of domestic industries, including job creation. The study therefore seeks to provide measures to foster specialists in order to enable the transfer of management through an opinion survey of fishermen. To cultivate specialists for enabling the transfer of management, the following solution should be promoted at the state level. First, to support the introduction of young and talented workers to the fisheries industry through transfer of management, Second, in order to enable the transfer of management, change is required first in the fisheries industry for it to become a value-added industry. Third, despite fisheries being a composite industry that is syncretized to tertiary industries from primary industries, the fisheries industry is still recognized as a labor intensive industry, which reflects the current status of fisheries education.

• Journal of the Korean Dietetic Association
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• v.13 no.3
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• pp.277-294
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• 2007

The purposes of this study were to a) examine using status, b) measure the service quality attributes, c) analyze IPA and customer satisfaction, d) develop the LSM(Local Store Marketing) by location of K theme restaurant such as residential type(A), complex type(B) and downtown type(C). The questionnaires were handed out to 346 of 450(usage rate 76.9%). The statistical data analysis was completed using SPSS(ver 12.0) for descriptive analysis, $X^2$, t-test, ANOVA, reliability analysis, factor analysis, multiple linear regression. From an analysis on service quality attributes, most importance of service quality attributes was more highly perceived than performance of those, except for 'attractive exterior', 'variety of kid's menu', 'convenient facilities for kid' and perceived importance and performance were also significantly different by location of branch restaurant. The attributes to be improved were 'convenience of restaurant's parking lot', 'food tast', 'speedy service' and 'service competency' as branch A(residential type) restaurant, 'convenience of the restaurant location' as branch B(complex type) restaurant and 'convenience of the restaurant location' and 'speedy service' as branch C(downtown type) through IPA analysis. The Overall customer satisfaction was 3.74 and service quality factors had significant effect on overall customer satisfaction. Location of restaurant, which gives a great effect on its operation and marketing, has a important correlation with success or failure of restaurant business enterprises. Therefore, marketing strategy by restaurant location should be developed.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.271-279
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• 2018

Various technologies have been developed to more efficiently share content such as P2P and CDN. These technologies take a common approach that request packets are responded by distributed network nodes, not by a single distributor. Such approaches not only resolve network congestion around content distributors, but also make it possible to distribute content regardless of the system and network status of content distributors. However, when receiving content from distributed nodes/hosts, not from authenticated distributors, users cannot practically identify which node/host sent content to them. Due to this characteristic, various hacking caused by the malicious modification of content is possible. Therefore, to make such approaches more secure, a content authentication technique is required. In this paper, we propose a improved operation of MHT used in CCN for authenticating distributed content. Then we evaluate the proposed method by comparing its performance with the existing technology.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.419-423
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• 2011

Unlike other non-destructive inspection method, AE Structural defects that are likely to grow in the operation status can be detected, and the advantage of being due to the continuous monitoring of large structures has been widely used to evaluate the stability. AE sensor used to detect sound wave that occurs between 20kHz to 20MHz. and Sound wave result may vary depending on sensor's sensitivity. In this paper, Tensile test conducted on STS 304 and SS400, and tries to detect the crack signal. In tensile test, specimens were conducted using different sensor sensitivity to the same tensile test condition. The crack signal parameters divided into 4 types of communities by conducting cluster analysis. It was demonstrated that crack signal of two sensor is not different by statistical analysis of null hypotheses. Based on the results, waveform of this tension test is crack signal.

• Nuclear Engineering and Technology
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• v.43 no.4
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• pp.317-328
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• 2011

Pyroprocessing technology was developed in the beginning for metal fuel treatment in the US in the 1960s. The conventional aqueous process, such as PUREX, is not appropriate for treating metal fuel. Pyroprocessing technology has advantages over the aqueous process: less proliferation risk, treatment of spent fuel with relatively high heat and radioactivity, compact equipment, etc. The addition of an oxide reduction process to the pyroprocessing metal fuel treatment enables handling of oxide spent fuel, which draws a potential option for the management of spent fuel from the PWR. In this context, KAERI has been developing pyroprocessing technology to handle the oxide spent fuel since the 1990s. This paper describes the current status of pyroprocessing technology development at KAERI from the head-end process to the waste treatment. A unit process with various scales has been tested to produce the design data associated with the scale up. A performance test of unit processes integration will be conducted at the PRIDE facility, which will be constructed by early 2012. The PRIDE facility incorporates the unit processes all together in a cell with an Ar environment. The purpose of PRIDE is to test the processes for unit process performance, operability by remote equipment, the integrity of the unit processes, process monitoring, Ar environment system operation, and safeguards related activities. The test of PRIDE will be promising for further pyroprocessing technology development.

• Journal of the Korean Dietetic Association
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• v.23 no.4
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• pp.384-396
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• 2017

School gardens are known to be effective for increasing vegetable consumption in children. This study was carried out to examine the perception of garden program leaders for actual conditions and barriers to promote school gardens according to their sense of dedication. The 49 garden program leaders at schools and child care centers in Pocheon city were surveyed and grouped into two groups: dedicated (57.1%) and less dedicated (42.9%) as program leaders. Compared to dedicated leaders, leaders in the less dedicated group less advocated promotion of school gardens (P<0.001) and were less willing to attend training for school garden (P<0.01), despite less experience as program leaders (P<0.01) and past training (P<0.05). Moreover, leaders in the less dedicated group less acknowledged the educational results of school garden in every aspect (P<0.001, respectively), less perceived support from parents and colleagues (P<0.05, respectively), and less used garden produce in more active activities such as donation and literature (P<0.05, respectively), compared to the dedicated group. The most answered barrier against the promotion of school gardens was work burden, followed by manpower shortage, shortage of technique, knowledge, and information, and time shortage. The results of this study provide evidence that developing strategies is needed to make more teachers and child care providers more dedicated as garden program leaders.

• Journal of Korean Library and Information Science Society
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• v.51 no.3
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• pp.149-169
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• 2020

This study focused on library services for patients and carers and conducted an awareness survey on the current status of library services for patients and carers in hospitals in Korea and on future library services for patients and carers. Through this, the ways to activate library services for patients and carers in the hospital were sought. Based on the results of the study, the research team proposes the following measures: First, the legislation for the mandatory establishment of libraries in hospitals and standards for the size, book collection, and manpower of libraries in hospitals should be enacted. Second, cooperation between the Ministry of Culture, Sports and Tourism, and the Ministry of Health and Welfare is essential to lay the foundation for the mandatory and voluntary establishment of hospital libraries at the national level in the future. Third, the operation of regional representative libraries, public libraries, and other institutions should be considered.