• Journal of Internet Computing and Services
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• v.19 no.1
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• pp.67-76
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• 2018

This paper addresses the problem of efficient processing of region monitoring queries. The centralized methods used for existing region monitoring query processing assumes that the mobile object periodically sends location-updates to the server and the server continues to update the query results. However, a large amount of location updates seriously degrade the system performance. Recently, some distributed methods have been proposed for region monitoring query processing. In the distributed methods, the server allocates to all objects i) a resident domain that is a subspace of the workspace, and ii) a number of nearby query regions. All moving objects send location updates to the server only when they leave the resident domain or cross the boundary of the query region. In order to allocate the resident domain to the moving object along with the nearby query region, we use a query index structure that is constructed by splitting the workspace recursively into equal halves. However, However, the above index structure causes unnecessary division, resulting in deterioration of system performance. In this paper, we propose an adaptive split method to reduce unnecessary splitting. The workspace splitting is dynamically allocated i) considering the spatial relationship between the query region and the resultant subspace, and ii) the distribution of the query region. We proposed an enhanced QR-tree with a new splitting method. Through a set of simulations, we verify the efficiency of the proposed split methods.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.75-82
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• 2005

To relieve congestion in the current system of intercity transportation, the Korea decided in 1990 to construct a high-speed railroad between Seoul and Busan and it is now in operation. This new mode of transportation significantly cut travel time between major cities and a trip from Seoul to the southeastern port of Busan. Since the KTX opening, average daily passenger numbers on both the Gyeongbu and Honam lines have increased about 1.3 fold over 2003 levels. As of December 2004, the KTX trains are carrying about 81,000 people a day. On KTX routes, the daily number of airline passengers dropped. Express long-distance bus traffic also dropped by 20% to 30%, while that on short-distance routes (100km or less) increased by about 20%. These figures clearly indicate that the Korean transportation network is becoming railroad-centric. However, the number of KTX passengers is fewer than anticipated possibly due to the Korean economic downturn and the operation of the KTX will leave many existing Saemaul and Mugunghwa train sets idle, which will be put into operation for areas, not covered by the KTX. When all the existing major lines have been electrified, more high-speed rail services will be phased in using direct connections to maximize operational efficiency. And also, the dual management by KTX and conventional rail will be regarded as the promotion of the benefit of the public.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.18-26
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• 2019

The Maritime Labour Convention, 2006, (MLC) aimed to ensure decent working conditions for seafarers and entered into force on August 20, 2013. It was considered as the fourth pillar in the maritime sector. This paper evaluates how the MLC has been implemented in the field and what issues were addressed in the shipping industry. To achieve this, statistical analysis was conducted using inspection data of Port State Control (PSC) carried out by the Paris MOU and the Tokyo MOU during 2010-2012 and 2014-2016 for deficiencies under the MLC and International Labour Organization (ILO) No. 147 Convention. This study compared pre-2013 and post-2013 deficiency data according to ship's age, size (gross tonnage) and type. The results showed that, although the deficiencies reported by the Tokyo MOU during 2014-2016 were nearly double those from 2010-2012, the deficiency share against total deficiencies for the Tokyo MOU remained two thirds of those for the Paris MOU. This study suggests that the Tokyo MOU should strengthen its inspection efforts on MLC and ILO should provide clear references, such as guidelines and a unified interpretation for national discretions under the MLC for the purpose of harmonized PSC inspections. Additionally, it would be desirable to consolidate the deficiency coding system for the MLC by deleting the codes for the ILO No. 147 Convention, which was incorporated into the MLC. It would also be beneficial to add new deficiency codes for social security, including seafarers' leave and repatriation.

• Journal of Platform Technology
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• v.11 no.2
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• pp.39-53
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• 2023

Non-installation program (hereinafter referred to as "portable program") is a program that can be used without an installation process, unlike general software. Since there is no separate installation process, portable programs have high mobility and are used in various ways. For example, when initial setup of multiple PCs is required, a portable program can be stored on one USB drive to perform initial setup. Alternatively, when a problem occurs with the PC and it is difficult to boot normally, Windows PE can be configured on the USB drive and portable programs can be stored for PC recovery. And the portable program does not directly affect PC settings, such as changing registry values, and does not leave a trace. This means that the portable program has high security. If a portable program is deleted after using it, it is difficult to analyze behavior in a general way. If a user used a portable program for malicious behavior, analysis in a general way has limitations in collecting evidence. Therefore, portable programs must have a new way of behavioral analysis that is different from ordinary installation software. In this paper, after installing the Windows 10 operating system on a virtual machine, we proceed with the scenario with a portable program of Opera and Notepad++. And we analyze this in various ways such as file analysis of the operating system and memory forensics, collect information such as program execution time and frequency, and conduct specific behavioral analysis of user.

• Journal of Intelligence and Information Systems
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• v.25 no.1
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• pp.139-161
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• 2019

The utilization of the e-commerce market has become a common life style in today. It has become important part to know where and how to make reasonable purchases of good quality products for customers. This change in purchase psychology tends to make it difficult for customers to make purchasing decisions in vast amounts of information. In this case, the recommendation system has the effect of reducing the cost of information retrieval and improving the satisfaction by analyzing the purchasing behavior of the customer. Amazon and Netflix are considered to be the well-known examples of sales marketing using the recommendation system. In the case of Amazon, 60% of the recommendation is made by purchasing goods, and 35% of the sales increase was achieved. Netflix, on the other hand, found that 75% of movie recommendations were made using services. This personalization technique is considered to be one of the key strategies for one-to-one marketing that can be useful in online markets where salespeople do not exist. Recommendation techniques that are mainly used in recommendation systems today include collaborative filtering and content-based filtering. Furthermore, hybrid techniques and association rules that use these techniques in combination are also being used in various fields. Of these, collaborative filtering recommendation techniques are the most popular today. Collaborative filtering is a method of recommending products preferred by neighbors who have similar preferences or purchasing behavior, based on the assumption that users who have exhibited similar tendencies in purchasing or evaluating products in the past will have a similar tendency to other products. However, most of the existed systems are recommended only within the same category of products such as books and movies. This is because the recommendation system estimates the purchase satisfaction about new item which have never been bought yet using customer's purchase rating points of a similar commodity based on the transaction data. In addition, there is a problem about the reliability of purchase ratings used in the recommendation system. Reliability of customer purchase ratings is causing serious problems. In particular, 'Compensatory Review' refers to the intentional manipulation of a customer purchase rating by a company intervention. In fact, Amazon has been hard-pressed for these "compassionate reviews" since 2016 and has worked hard to reduce false information and increase credibility. The survey showed that the average rating for products with 'Compensated Review' was higher than those without 'Compensation Review'. And it turns out that 'Compensatory Review' is about 12 times less likely to give the lowest rating, and about 4 times less likely to leave a critical opinion. As such, customer purchase ratings are full of various noises. This problem is directly related to the performance of recommendation systems aimed at maximizing profits by attracting highly satisfied customers in most e-commerce transactions. In this study, we propose the possibility of using new indicators that can objectively substitute existing customer 's purchase ratings by using RFM multi-dimensional analysis technique to solve a series of problems. RFM multi-dimensional analysis technique is the most widely used analytical method in customer relationship management marketing(CRM), and is a data analysis method for selecting customers who are likely to purchase goods. As a result of verifying the actual purchase history data using the relevant index, the accuracy was as high as about 55%. This is a result of recommending a total of 4,386 different types of products that have never been bought before, thus the verification result means relatively high accuracy and utilization value. And this study suggests the possibility of general recommendation system that can be applied to various offline product data. If additional data is acquired in the future, the accuracy of the proposed recommendation system can be improved.

• Journal of Korea Technology Innovation Society
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• v.16 no.4
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• pp.1032-1054
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• 2013

An increase of national R&D has brought the growth of research performance such as paper and patent quantitatively. However, the results of technology transfer and commercialization still leave much to be desired in Korea. Therefore, it has to be drawn up a plan for effective management & application of research performance created by public research institutes. We select four leading institutes (two universities, two government-funded research institutes) that performed efficient performance management & application. Then, we analyze the best practices and suggest contributions. The results show that four institutes build up a framework of performance management & application from research planning to technology transfer and commercialization. At an early planning phase, institutes set up definite needs-oriented goals, and prior review as well as prior art search is executed through experts. Besides, they systematically promote strategic patent management, technology marketing, post management, and so forth. For such a performance management & application process, capabilities have to be supported with regard to specialized organization, system, routine. This study can give an hint to improve performance management & application from public research institutes in Korea.

• Industry Promotion Research
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• v.5 no.3
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• pp.61-71
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• 2020

The purpose of this paper is to reaffirm the logical framework of the saju analysis method by recreating the saju model of old-law to study and organize the theories of frame in old-law Myeongri, and then by organizing and comparing the logic structure of the saju analysis method of new-law and old-law. Some believe that Myeongri Theory first appeared in the world in the Warring States Period when they were active with Gwigokja and Naknokja as origin, while others believe that it was origin that "Okjokyeong" was written by Kwak-Bak of Eastern Jin after a while. Since then, Myeongri Theory, which had been organized by Won-Cheongang and Yi-Heojung, has undergone a major transformation since reaching the Song Dynasty Seo-Japyeong. Based on this point, the Myeongri Theory of the previous generation is called the Old-law, and the subsequent theory is called the New-law. The changes in the logic structure of the old-law and the new-law leave a big difference and disconnect between those. But comparative studies have confirmed that the philosophy and logic structure due to natural laws that have not changed much such as the symbolic system of nature called Yinyang & five elements and Cheongan-jiji, the idea of a heavenly response projected in the Three Wonders of heaven, earth and human, and the concept of generation and time in the position of year-month-day-time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.427-434
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• 2019

In the present study, we assessed the parallel computing performance of Agisoft Metashape for orthomosaic generation, which can implement aerial triangulation, generate a three-dimensional point cloud, and make an orthomosaic based on SfM (Structure from Motion) technology. Due to the nature of SfM, most of the time is spent on Align photos, which runs as a relative orientation, and Build dense cloud, which generates a three-dimensional point cloud. Metashape can parallelize the two processes by using multi-cores of CPU (Central Processing Unit) and GPU (Graphics Processing Unit). An orthomosaic was created from large UAV (Unmanned Aerial Vehicle) images by six conditions combined by three parallel methods (CPU only, GPU only, and CPU + GPU) and two operating systems (Windows and Linux). To assess the consistency of the results of the conditions, RMSE (Root Mean Square Error) of aerial triangulation was measured using ground control points which were automatically detected on the images without human intervention. The results of orthomosaic generation from 521 UAV images of 42.2 million pixels showed that the combination of CPU and GPU showed the best performance using the present system, and Linux showed better performance than Windows in all conditions. However, the RMSE values of aerial triangulation revealed a slight difference within an error range among the combinations. Therefore, Metashape seems to leave things to be desired so that the consistency is obtained regardless of parallel methods and operating systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.329-338
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• 2018

This study was conducted to examine musculoskeletal disorder and analyze the effects of musculoskeletal pain control and self-efficacy on musculoskeletal disorders in dental hygienists. Material and Methods; 483 dental hygienists residing in Gwangju were collected by the convenience sampling method and the self-administered questionnaire survey was conducted. Frequency analysis, crosstab analysis, t-test, and multiple logistic regression analysis were used for analysis. Results: the prevalence of musculoskeletal pain among subjects was 83.9% for the prior year, with 29.8% of patients being afflicted by musculoskeletal disorders. The factors influencing musculoskeletal disorders were musculoskeletal pain resolution. For pain resolution, the odds ratio of musculoskeletal disorders of the group who answered treatment in a hospital, an Oriental medicine clinic, or a pharmacy was 0.22 (95% confidence interval, 0.14-0.34) compared with the group who answered sick leave or task change, suggesting a negative relationship. These findings indicate that people with musculoskeletal disorders were not treated in the hospital, Oriental medicine clinic, or pharmacy. Therefore, it is necessary to improve medical management (oriental medicine, intravenous injection or medication, heat therapy or cryotherapy, steroid treatment, counseling, endovascular treatment using spinal cord stimulation, physical therapy, stretching, rehabilitation, and manual therapy) and job environment and to make a good approach to the prevention of musculoskeletal disorders to control dental hygienists' musculoskeletal pain.

• Korean Journal of Social Welfare
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• v.57 no.2
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• pp.41-70
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• 2005

The object of the study is to examine the change of social-economic structure and poverty-shape to escape poverty. In Korea, the working poor have been increased by flexibility and division of labor market since the economic crisis in 1997, and are faced with hard conditions due to the vulnerable welfare system. Especially the workers who engage in irregular jobs were increased by restructure of labor market. Besides they are in unstable employment terms such as low payment, low-skill and exclusion from welfare-benefit. Many small independent businessmen are also in danger of poverty for enterprises trend to move abroad by globalization. Poverty policy in our country was focused on the absolute poor class that has relation with old age, unemployment, disable, disease etc, so they were the object of welfare policy. The poverties, however, are increasing rapidly after the economic crisis, and they work so hard but are still poor, that is, participation in labor market doesn't become an element to escape poverty. Thus the emergence of new poverties whose core consists of the working poor becomes to need new poverty policy. The study is to survey change of their economic conditions, their welfare conditions, their experiences and responses of social dangers after the economic crisis, then to explore the policy to escape poverty. As the result of the study, it shows that the working poor experienced many kinds of social dangers like unemployment, decrease of income etc. In their welfare conditions as their responses to the social dangers, the benefit of social insurance, enterprise welfare like legal retirement pay and paid leave and private welfare such as private pension and insurance are low. The working poor are faced with social dangers, moreover, they don't have skill or education for adapting themselves to information society. The study says that it needs variable policies for the working poor to escape poverty, and suggests payment & tax policies as stable income policy, occupational discipline and skill-education for promoting the quality of employment, moreover, social insurance as expansion of social welfare policy and housing & education policies whose objects are the working poor.