• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.368-375
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• 2013

Failure of small bore piping welds is a recurring problem at nuclear power plants. And the socket weld cracking in small bore piping has caused unplanned plant shutdowns for repair and high economic impact on the plants. Consequently, early crack detection, including the detection of manufacturing defects, is of the utmost importance. Until now, the surface inspection methods has been applied according to ASME Section XI requirements. But the ultrasonic inspection as a volumetric method is also applying to enforce the inspection requirement. However, the conventional manual ultrasonic inspection techniques are used to detect service induced fatigue cracks. And there was uncertainty on manual ultrasonic inspection because of limited access to the welds and difficulties with contact between the ultrasonic probe and the OD(outer diameter) surface of small bore piping. In this study, phased array ultrasonic inspection technique is applied to increase inspection speed and reliability. To achieve this object, the 3.5 MHz phased array ultrasonic transducer are designed and fabricated. The manually encoded scanner was also developed to enhance contact conditions and maintain constant signal quality. Additionally inspection system is configured and inspection procedure is developed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.1
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• pp.25-31
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• 2012

The frequency and abundance of jellyfish, presumably related with climate change, fisheries overexploitation, marine pollution including land reclamation and dyke construction, are increasing worldwide. This feature has attracted interest and concerns from general public and public officials, and government is seeking how the damages could be prevented or reduced down. Korean government, having recent huge blooms of jellyfish, engaged in reducing and/or countermeasuring jellyfish damages. Korean research themes include ecology and physiology of blooming jellyfish species, understanding of the blooming mechanism, and focus on the eradication of blooming jellyfish, without governmental integrative management plan. EU is undertaking scientific projects focused on understanding of the mechanism and control of jellyfish blooms, and establishment of an integrative management. In USA, government has established the code on jellyfish management for conserving and protecting the fish and shellfish resources and one of its department is specially assigned to monitor jellyfish appearance, undertake research, and prepare management plan. Japan also assigned a department and research institute for jellyfish research. Their main interest is to predict jellyfish drifting and mass bloom. Compared to Korea, USA, EU and Japan emphasize integrative management that includes ecological understanding, public education and outreaches, communication and control, if possible, of jellyfish blooms, based on scientific data. We suggest then, 1) establishment of an integrative scientific system consisting of policy and scientific experts to prepare inter-ministrial integrative management plan to effectively combat jellyfish blooms and to maximize the scientific result; 2) concept change from harmful to exploitable marine animal in policy making and research; and 3) active education and information service for people. We expect that these suggestions can be useful for jellyfish management and policy making on another harmful marine organisms.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.34-43
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• 1977

This study attempts to examine the performances of Myun Health Workers-the frontline workers in the Korean rural health care delivery system. The time-activity approach was mainly utilized as a measuring tool. This study was undertaken in September 1976 with 35 Myun Health Workers at the Kang Wha County. The pretested time-activity approach sheets were filled out daily for one month by those Myun Health Workers themselves. Statistical means and variances of analysis were utilized for statistical method in comparing some activities and functions converged into time distribution Findings: 1. The workers's average working hours derived in this study is 8 hours and 48 minutes per day, which takes half an hour longer than normal schedule. 2. They spend 56% working hour for direct services, in other words, the main function, 22% for supportive function, and 22% for other activities, the unrelated health services. 3. Considering the total working hours of main function, out-center activity is far more than in-center services with the ratio of 70% to 30% respectively, which proves, therefore, that the main activity of the workers is home visiting. 4. It takes 20 minutes purely for home visiting and takes 14 minutes for transportation. 5. This research also indicates that such factors as characteristics of the health workers and myun influence in shaping the structures of the worker's function and activity: a. The workers whose working site is located in myun office spend 15% among total working hours in carring out official myun activities, which is incidentally unrelated to health services, while the health subcenter have no rooms for administrative jobs for myun office. b. The workers whose office is in health subcenter contribute much time in doing main function and those working in special project distribute more time in performing supportive function. c. The types of workers are another dominant factor to influence the components of worker's functions and activities. MCH workers and MPW I spend much time for manipulating main function. d. MPW II, whose function is reorganized by special project in 2 myuns shows different pattern of time distribution compared to the TB worker orFP worker in the ordinary area. MPW II distributes their time evenly in performing MCH program, T.B. Program, F.P. program and education activity, while the unipurpose workers engage in carring out only their dominant role. e. Another variables which involve the variation of the worker's activity can be illustrated with the variables like target population, size of myun and convenience for transportation, among which the latter two are remarkable factors in determining the time for out-center service.

• Korean Security Journal
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• no.38
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• pp.163-189
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• 2014

This research is carried out to offer suggestions for improving the work efficiency and quality of private security officers and developing the private security industry; it examines the relationship between the training of private security officers that affects task efficiency as well as the ultimate outcome of an organization's work and job satisfaction while confirming the mediation effect of job consciousness. A self-administration survey method is employed and the questionnaires filled out by 180 related personnel at a private security firm located in Seoul, South Korea are analyzed for the following results. The training satisfaction variable shows a statistically significant effect on the job consciousness of private security officers, meaning that the trainees that are satisfied with the training they receive are also more dedicated to carrying out their tasks dutifully compared to those who are not content with the training. The research results stated above confirm the findings of the past studies which assert that training satisfaction factor affects job satisfaction and job consciousness has a statistically significant impact on job satisfaction and acts as a mediator between training and job satisfaction. With the results acquired, the author suggests the training providers and instructors prepare an educational service that can suit the needs of the trainees and promote job consciousness through increased training satisfaction. Lastly, with the basis on the results from this study, further research should be conducted to examine other various explanatory factors that might affect job satisfaction.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.4
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• pp.235-238
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• 2008

The Water Erosion Prediction Project (WEPP) was initiated in August 1985 to develop new generation water erosion prediction technology for federal agencies involved in soil and water conservation and environmental planning and assessment. Developed by USDA-ARS as a replacement for empirical erosion prediction technologies, the WEPP model simulates many of the physical processes important in soil erosion, including infiltration, runoff, raindrop detachment, flow detachment, sediment transport, deposition, plant growth and residue decomposition. The WEPP included an extensive field experimental program conducted on cropland, rangeland, and disturbed forest sites to obtain data required to parameterize and test the model. A large team effort at numerous research locations, ARS laboratories, and cooperating land-grant universities was needed to develop this state-of-the-art simulation model. The WEPP model is used for hillslope applications or on small watersheds. Because it is physically based, the model has been successfully used in the evaluation of important natural resources issues throughout the United State and in several other countries. Recent model enhancements include a graphical Windows interface and integration of WEPP with GIS software. A combined wind and water erosion prediction system with easily accessible databases and a common interface is planned for the future.

• Korean Journal of Social Welfare
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• v.67 no.4
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• pp.127-152
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• 2015

This study aimed to implement the enhancement program for the social work practice competency for children of community child center workers and to evaluate the program's effects. For this purpose, the program was implemented for ten community child center workers five times for five weeks(once a week, 120 minutes per session). For the quantitative evaluation, a non-equivalent control group design among quasi-experimental designs was used, and for the qualitative evaluation, the written materials related with the program were collected and analyzed. The results of the quantitative evaluation revealed that the social work practice skills and worker-client relationship empowerment of the community child center workers who participated in the competency enhancement program were significantly improved. In the qualitative evaluation, the subjective experiences were presented, including the improvement of the worker's practice competency and the worker's awareness of the changes in the child, the recognition of the strong points and the points to be improved in the program. This study is expected to raise the expertise and effectiveness of community child center workers, and ultimately, to contribute to the healthy development and the improvement of the mental health of children by improving the social work practice competency of the workers in community child centers, which comprise the representative service delivery system for children in South Korea.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.85-90
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• 2017

Indoor location-based services have been developed based on the Internet of Things technologies which measure and analyze users who are moving in their daily lives. These various indoor positioning technologies require separate hardware and have several disadvantages, such as a communication protocol which becomes complicated. Based on the fact that a reduction in signal strength occurs according to the distance due to the physical characteristics of the transmitted signal, RSSI technology that uses the received signal strength of the wireless signal used in this paper measures the strength of the transmitted signal and the intensity of the attenuated received signal and then calculates the distance between a transmitter and a receiver, which requires no separate costs and makes to implement simple measurements. It was applied calculating the value for the average RSSI and the RSSI filtering feedback. Filtering is used to reduce the error of the RSSI values that are measured at long distance.It was confirmed that the RSSI values through the average filtering and the RSSI values measured by setting the coefficient value of the feedback filtering to 0.5 were ranged from -61 dBm to - 52.5 dBm, which shows irregular and high values decrease slightly as much as about -2 dBm to -6 dBm as compared to general measurements.

• The Journal of Korean Association of Computer Education
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• v.11 no.6
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• pp.65-76
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• 2008

Since Cyber Home Learning is an e-learning system promoted with policy goals of reducing private tutoring costs, solving gaps among regions, and improving scholastic attainments, preceding researches to verify its effects have been developed of evaluation standards focused on achievement of its policy goals rather than educational goals. The evaluation standards suggested in preceding researches have limitations in clearly reviewing Cyber Home Learning's effects by teaching-learning activities factors and Cyber Home Learning's improvement related to teaching-learning activities. Therefore, an evaluation model capable of analyzing effects of Cyber Home Learning from pedagogical aspect is required. The goal of this paper is to design pedagogical evaluation model according to teaching-learning activities factors and analyze effects of Cyber Home Learning. For the goal, researches from Korea and abroad related to Cyber Home Learning have been examined, pedagogical evaluation model was designed according to teaching-learning activities factors, and the model was then experimented through survey and in-depth interview on students who used Cyber Home Learning. It is expected that results of this paper can be used as a basic data to improve quality of Cyber Home Learning service for teaching-learning activities, and will contribute to establishment of more developmental Cyber Home Learning policy in the future.

• Korean journal of communication and information
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• v.84
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• pp.7-27
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• 2017

This study explores the possibility of maximizing locality through synergy between local terrestrial broadcasters and cable local channels. To this end, it examines the significance of the concept of locality in the changing environment represented by the 4th Industrial Revolution. It also analyzes the existing situation of broadcasting locality and the terrain of existing studies concerning cable local channels. Based on the reviews, the study searches for the connection points between local terrestrial and cable channels, which are still heterogeneous operators. The difference in the size of broadcast region and the programming time constitutes the optimum condition. As a result of this, the study discusses the issue of appropriateness and feasibility of bundling the local terrestrial and pay-TV channels in the same legal system. By doing so, it reveals the biggest obstacle in institutionalizing the cable channel into the public category is the emotional rejection towards cable TV. In order to overcome this problem, the study suggests to abolish both the current policy guideline characterized as the same service, same regulation principle and the abolition of local business right of cable TV. It also proposes to allow news commentary function of cable local channels and strengthen cable TV's own capabilities.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.809-820
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• 2008

A new modified full scale double tee slabs with the length of nib plate - 1,500 mm were suggested, designed, and experimentally evaluated up to the loading of flexural failure. This slabs were composed of the tee section which was same to original PCI double tee and the plate section which was modified in a new shape, and the prestressing force was applied at the bottom of tee section only. This specimens were made from the domestic precast factory. The safety and serviceability of the modified nib plate with the dapped ends were evaluated up to the ultimate flexural strength of tee section. As the experimental loading increased, the flexural crackings developed first in the bottom of the slab and they changed to the increased flexural shear and inclined shear crackings in the nib and dapped portion of the double tees. The suggested modified double tee slabs failed in ductile above the design loading with many evenly distributed flexural crackings. The thickness of nib plate - 250 mm does not show any cracking under the service loading and show several minor flexural cracking up to the ultimate state of tee portion. The proposed specimens were satisfied with the strength and ductility requirements in the design code provisions in the tests. Additional experimental tests are required to reduce the depth and tensile reinforcement of nib plate concrete for the practical use of this system effectively.