• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.240-243
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• 2010

Objective : Radiofrequency (RF) medial branch neurotomy is an effective management of lumbar facet syndrome. However, pain may recur after period of time. When pain recurs, it can be repeated, but the successful outcome and duration of relief from repeated procedures are not clearly known. The objective of this study was to determine the success rate and duration of pain relief from repeated radiofrequency medial branch neurotomy for lumbar facet syndrome. Methods : A retrospective review of medical records was done on 60 consecutive patients, from March of 2006 to February of 2009, who had an initial successful RF neurotomy but subsequently underwent repeated procedures due to recurrence of pain. All procedures were done in carefully selected patients after at least two responsive medial branch nerve blocks. C-arm fluoroscopic guide, impedance, sensory and motor threshold monitoring tools were used for the precise placement of electrodes. Responses of repeated procedures were compared with initial radiofrequency neurotomy for success rates and duration of pain relief. Results : There were 48 females and 12 males. Mean age was 52.4 years (range, 26-83). RF medial branch neurotomy was done on one side in 38 and both sides in 22 patients, each covering at least three segments. Average visual analog scale at last procedure was 6.8. Twelve patients had previous lumbar operations, including 4 patients with instrumentations. Fifty-five patients had two procedures and five patients had three procedures. Mean duration of successful pain relief (> 50% of previous pain for at least 3 months period) after initial radiofrequency neurotomy was 10.9 months (range, 3-28) in 51 (85%) patients. From repeated procedures, successful pain relief was seen in 50 (91%) patients with average duration of 10.2 months (range, 3-24). Five patients had third procedure, which was successful in 4 (80%) patients with mean duration of 9.8 months (range, 5-16). This was not statistically different from initial results. There were no permanent neurological complications from the procedures. Conclusion : Results of this study indicate that the frequency of success and durations of relief from repeated RF medial branch neurotomy for lumbar facet syndrome are similar to initial results that provided relatively prolonged period of pain relief without major side effects Each procedure seems to provide successful pain relief for about 10 months in more than 85% of carefully selected patients when properly done.

• The Journal of Society for e-Business Studies
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• v.18 no.4
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• pp.145-167
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• 2013

This paper proposes a method to compare planned processes with actual processes of bock assembly operations in shipbuilding industry. Process models can be discovered using the process mining techniques both for planned and actual log data. The comparison between planned and actual process is focused in this paper. The analysis procedure consists of five steps : 1) data pre-processing, 2) definition of analysis level, 3) clustering of assembly bocks, 4) discovery of process model per cluster, and 5) comparison between planned and actual processes per cluster. In step 5, it is proposed to compare those processes by the several perspectives such as process model, task, process instance and fitness. For each perspective, we also defined comparison factors. Especially, in the fitness perspective, cross fitness is proposed and analyzed by the quantity of fitness between the discovered process model by own data and the other data(for example, the fitness of planned model to actual data, and the fitness of actual model to planned data). The effectiveness of the proposed methods was verified in a case study using planned data of block assembly planning system (BAPS) and actual data generated from block assembly monitoring system (BAMS) of a top ranked shipbuilding company in Korea.

• Journal of Environmental Impact Assessment
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• v.29 no.2
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• pp.132-143
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• 2020

The purpose of this study is to identify the accomplishments and limits of the local governments' environmental impact assessment operation system and to propose a policy plan to improve it through an analysis of the current status of the operations by local governments. As the research method, based on an understanding of the basic purpose and concept of the local government's environmental impact assessment, the current status of environmental impact assessment by major local governments such as Seoul, Jeju, Busan, Daejeon, etc. is analyzed and in-depth interviews with public officials in charge are conducted. Through the extensive discussions, the current situation and the problems are identified. The accomplishments of the local governments' operation of environmental impact assessment are: it is possible, first, to select evaluation targets and items in accordance with regional characteristics; second, to continuously strengthen the management and monitoring the evaluation result after through its own follow-up control. The limits revealed are; first, internal organization problems, which are largely due to the fact that the project approvers and the environmental impact assessment consultants are the same; second, poor cooperation system between the department of environmental impact assessment and other departments; third, lack of professionalism in the working forces; and forth, a limited pool of the skilled judges; and last, it was found that there could be frequent problems of overlapping regulation during coordinating target projects and evaluation contents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.602-608
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• 2020

Development of Internet technology and the spread of various smart devices provide a convenient computing environment for people, which is becoming common thanks to the Internet of Things (IoT). However, attacks by hackers have caused various problems, such as leaking personal information or violating privacy. In the IoT environment, various smart devices are connected, and network attacks that are used in the PC environment are occurring frequently in the IoT. In fact, security incidents such as conducting DDoS attacks by hacking IP cameras, leaking personal information, and monitoring unspecified numbers of personal files without consent are occurring. Although attacks in the existing Internet environment are PC-oriented, we can now confirm that smart devices such as IP cameras and tablets can be targets of network attacks. Through performance evaluation, the proposed protocol shows 11% more energy efficiency on servers than RSA, eight times greater energy efficiency on clients than Kerberos, and increased efficiency as the number of devices increases. In addition, it is possible to respond to a variety of security threats that might occur against the network. It is expected that efficient operations will be possible if the proposed protocol is applied to the IoT environment.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.1-15
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• 2017

Wetland function assessment is not only a basic step to understand wetland ecosystems in detail but also an important process as a base of the term, ecosystem service to recognize wetland ecosystems as valuable and useful resources and goods for human being. WET (wetland evaluation technique), EMAP (environmental monitoring assessment program)-wetlands, and HGM (hydrogeomorphic method) were developed as pioneer wetland function assessments in U.S. at the end of $20^{th}$-century. RAMs (rapid assessment methods) became a major function assessment tool which is relatively simpler and easier assessment tool at the beginning of $21^{th}$-century. After that, the hierarchy of three levels of assessment (landscape assessment, rapid assessment, and intensive assesment) has been prepared and strategically utilized according to the objectives and purposes of function assessments. In South Korea, RAM and HGM were used to assess wetland functions with reforming a couple of items and contents at 2001. And, modified and reformed function assessments have been developed to complement and improve upon the existing RAMs and HGMs. Via the trend analysis on wetland function assessments, some needs which require supplements in terms of function assessment are pointed out: 1) wetland function assessments using useful indicators such as birds are needed with considering our environmental characteristics. 2) optimized wetland function assessments for coastal wetlands are also needed. 3) the network construction and further expansion to lead communications and co-operations between researchers and policy makers is needed in the field of wetland function assessment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.147-158
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• 2016

Objectives: The objective of this study was to evaluate the assessment of exposure to welding fume and heavy metals among construction welders. Methods: Activity-specific personal air samplings(n=206) were carried out at construction sites of three apartment, two office buildings, and two plant buildings using PVC(poly vinyl chloride) filters with personal air samplers. The concentration of fumes and heavy metals were evaluated for five different types of construction welding jobs: general building pipefitter, chemical plant pipefitter, boiler maker, ironworker, metal finishing welder. Results: The concentration of welding fumes was highest among general building pipefitters($4.753mg/m^3$) followed by ironworkers($3.765mg/m^3$), boilermakers($1.384mg/m^3$), metal finishing welders($0.783mg/m^3$), chemical pipefitters($0.710mg/m^3$). Among the different types of welding methods, the concentration of welding fumes was highest with the $CO_2$ welding method($2.08mg/m^3$) followed by SMAW(shield metal arc welding, $1.54mg/m^3$) and TIG(tungsten inert gas, $0.70mg/m^3$). Among the different types of workplace, the concentration of welding fumes was highest in underground workplaces($1.97mg/m^3$) followed by outdoor($0.93mg/m^3$) and indoor(wall opening as $0.87mg/m^3$). Specifically comparing the workplaces of general building welders, the concentration of welding fumes was highest in underground workplaces($7.75mg/m^3$) followed by indoor(wall opening as $2.15mg/m^3$). Conclusions: It was found that construction welders experience a risk of expose to welding hazards at a level exceeding the exposure limits. In particular, for high-risk welding jobs such as general building pipefitters and ironworkers, underground welding work and $CO_2$ welding operations require special occupational health management regarding the use of air supply and exhaust equipment and special safety and health education and fume mask are necessary. In addition, there is a need to establish construction work monitoring systems, health planning and management practices.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.2
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• pp.353-370
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• 2016

This study examined elementary mathematics teacher's guidebook to determine the inclusion level of 11 critical features of evidence based instruction. And the inclusion level of the features in teacher's guidebook were interpreted as 'Low', 'Middle' and 'High'. The results are as followings. First, The overall inclusion level of the features in teacher's guidebook is 'Middle' The inclusion level of the features in teacher's guidebook for 1st, 2nd, 3rd and 4th were 'Middle' but for 5th and 6th were 'Low'. Second, the inclusion level of the features 'Clarity of Objective', 'Single Concepts and Skill Taught', 'Use of Manipulatives and Representation', 'Explicit Instruction', 'Provision of Examples for new concepts and skill', 'Adequate Independent Practice Opportunities' and 'Progress Monitoring' were 'Middle' The inclusion level of the features 'Review of Prerequisite Mathematical Skills', 'Error correction and Corrective Feedback' and 'Instruction of Strategies' were 'Low'. And discussed the results.

• Journal of Agricultural Extension & Community Development
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• v.23 no.2
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• pp.195-210
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• 2016

The study Development of the Agricultural Cooperative in Cambodia seek to explore the progress of agricultural cooperative( AC) development in Cambodia and South Korea. The experiences of Korea AC development are used to improve the Cambodian ACs. The results of study gave a lessons that the Korea ACs, which were multipurpose cooperatives were formed and owned by the government and had been considered as a successful development strategy for rural and agricultural development. As the government directly managed the businesses and other operations, available budgets, close with monitoring, and active member's participation the AC in Korea progressed rapidly for both the members and business scopes and it hugely contributed to rural development of Korea. For the future development of AC in Cambodia recommendations based on lessons from Korea AC will give a message to government and NGO. Rural Development always related with farmer's life. To live well in rural area provide effective mechanism to income increase. To development of AC in Cambodia is future of rural development.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.251-264
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• 2008

One of the crucial elements to fully facilitate the various benefits of intelligent transportation systems (ITS) is to obtain more reliable traffic monitoring in real time. To date, point and section-based traffic measurements have been available through existing surveillance technologies, such as loops and automatic vehicle identification (AVI) systems. However, seamless and more reliable traffic data are required for more effective traffic information provision and operations. Technology advancements including vehicle tracking and wireless communication enable the acceleration of the availability of individual vehicle travel information. This study presents a UBIquitous PRObe vehicle Surveillance System (UBIPROSS) using vehicle-to-vehicle (V2V) wireless communications. Seamless vehicle travel information, including origin-destination information, speed, travel times, and other data, can be obtained by the proposed UBIPROSS. A set of parameters associated with functional requirements of the UBIPROSS, which include the market penetration rate (MPR) of equipped vehicles, V2V communication range, and travel time update interval, are investigated by a Monte Carlo simulation- (MCS) based evaluation framework. In addition, this paper describes prototypical implementation. Field test results and identified technical issues are also discussed. It is expected that the proposed system would be an invaluable precursor to develop a next-generation traffic surveillance system.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.4
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• pp.420-425
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• 1999

The maximum demand controller is an electrical equipment installed at the consumer side of power system for monitoring the electrical energy consumed during every integrating period and preventing the target maximum demand (MD) being exceeded by disconnecting sheddable loads. By avoiding the peak loads and spreading the energy requirement the controller contributes to maximizing the utility factor of the generator systems. It results in not only saving the energy but also reducing the budget for constructing the natural base facilities by keeping thc number of generating plants ~ninimumT. he conventional MD controllers often bring about the large number of control actions during the every inteyating period and/or undesirable loaddisconnecting operations during the beginning stage of the integrating period. These make the users aviod the MD controllers. In this paper. fuzzy control technique is used to get around the disadvantages of the conventional MD control system. The proposed MD controller consists of the predictor module and the fuzzy MD control module. The proposed forecasting method uses the SOFM neural network model, differently from time series analysis, and thus it has inherent advantages of neural network such as parallel processing, generalization and robustness. The MD fuzzy controller determines the sensitivity of control action based on the time closed to the end of the integrating period and the urgency of the load interrupting action along the predicted demand reaching the target. The experimental results show that the proposed method has more accurate forecastinglcontrol performance than the previous methods.