• International Journal of Contents
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• v.12 no.1
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• pp.60-64
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• 2016

As new applications of cloud data management system (CDMS) such as online games, cooperation edit, social network, and so on, are increasing, transaction processing capabilities for CDMS are required. Several transaction processing methods for cloud data management system (CDMS) have been proposed. However, existing transaction processing methods have some problems. Some of them provide limited transaction processing capabilities. Some of them are hard to be integrated with existing CDMSs. In this paper, we proposed a new concurrency control method to support transaction processing capability for CDMS to solve these problems. The proposed method was designed and implemented based on Spark, an in-memory distributed processing framework. It uses RDD (Resilient Distributed Dataset) model to provide fault tolerant to data in the main memory. In our proposed method, database stored in CDMS is loaded to main memory managed by Spark. The loaded data set is then transformed to RDD. In addition, we proposed a multi-version concurrency control method through immutable characteristics of RDD. Finally, we performed experiments to show the feasibility of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.215-224
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• 2008

In this paper, we introduced a linear motor-based transfer system with an active pid controller which can be replaced with an automated guided vehicle (AGV) for the port automation. This system, which is named LMCTS(liner motor-based container transfer system), is based on PMLSM (permanent magnetic linear synchronous motor) which basically consists of stator modules on the rail and shuttle car. Therefore more progressive and adaptive control mechanisms should be required to control a system with large variation of container weight, the difference of each characteristic of stator modules, a stator module's trouble etc. We introduced an active control mechanism with an online tuning scheme using modified evolutionary strategy. Some computer simulations are implemented to assess the robustness of the proposed system.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.292-294
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• 2002

정보시스템을 구축하기 위한 기술구조는 90년대 초까지의 호스트 중심의 기술구조에서 PC보급의 확대로 인해 Client/server 환경의 기술구조를 급격하게 발전시켜 왔다. 그러나 Client/server 구조는 사용이 간편하고 시스템 확장이 용이하다는 장점에도 불구하고 Client 관리에 큰 문제점이 나타났다. Client/server 관리의 문제점을 해결할 수 있는 대안으로 웹 환경의 인터넷/인트라넷 구조의 기술발전이 꾸준히 이루어졌으며, 현재는 Client/server와 같은 안정적인 OLTP(Online Transaction Processing)를 처리할 수 있는 수준까지 발전하였다. 본 논문에서 소개하는 운송정보시스템은 웹 환경의 인터넷/인트라넷을 이용한 시스템으로서, 중ㆍ소 운송업체와 자가 운송 사업자가 운송정보시스템을 구축하는데 있어서 초기 투자비용을 줄이고, 시스템의 유지 보수 및 확장이 용이한 ASP(Application Service Provider) 서비스를 효과적으로 제공한다. 이것은 차량의 위치정보를 통해 배차현황/출하차현황/도착현황/공차현황 등 물류 흐름을 파악하기 위한 운송 정보를 실시간으로 제공하고, 동종 유사 업체간의 표준화된 자료를 교환, 공유함으로써 효율적인 차량 관리가 가능하며, 물류비를 전감 할 수 있고, 작업의 효율성을 증대시켜 원활한 운송업무가 이루어지게 할 수 있을 것이다.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1177-1180
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• 2005

The Ministry of Construction & Transportation(MOCT) in Korea handles electronically 38 kinds of approval and permit operations under the Construction Civil Affairs Administration System(CCAS) so that applicants may apply for construction permits with ease and concerned public offices may process effectively civil applications. In particular, road occupation permit operations have several problems to be improved. This study is aimed to improve the CCAS in terms of simplification of application receipt, issuance of online permit, auto calculation of road occupation fee, and auto issuance of payment notice.

• Journal of Practical Engineering Education
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• v.16 no.1_spc
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• pp.11-19
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• 2024

Web programming courses are often included in university Computer Science programs as introductory and foundational computer programming courses. However, amateur programmers often have difficulty learning how to integrate HTML, CSS, JavaScript, and various preprocessors or libraries to create websites. Additionally, many web programming mistakes do not produce visible output in the browser. Therefore, in recent years, Front-End Code Playground (FECP) tools that incorporate HTML, CSS, and JavaScript into a single, online web-based application have become popular. These tools allow web coding to happen directly in the browser and provide immediate visual feedback to users. Such immediate visual feedback can be particularly beneficial for amateur coders to learn and practice with. Therefore, this study gathers data on various FECP tools, compares their differences, and provides an analysis of how such tools benefit students. This study concludes with an outline of the application of FECP to web programming courses to enhance the learning experience.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.61-71
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• 2021

In a situation where the online learning is expanding due to COVID-19, the current maker education has limitations in applying it to classes. This study is to design the class of online maker education using artificial intelligence tools in elementary school. Also, it is to identify the responses to it and to confirm whether it helps improve the learner's computational thinking and creative problem solving ability. The class was designed by the literature review and redesign of the curriculum. Using interveiw, the responses of instructor and learners were identified. Pre- and post-test using corresponding sample t-test was conducted. As a result, the class consisted of ten steps including empathizing, defining making problems, identifying the characteristics of material and tool, designing algorithms and coding using remixes, etc. For computing thinking and creative problem solving ability, statistically significant difference was found. This study has the significance that practical maker activities using educational artificial intelligence tools in the context of elementary education can be practically applied even in the online environment.

• The Journal of Industrial Distribution & Business
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• v.10 no.5
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• pp.27-36
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• 2019

Purpose - Naver has emerged as a new leader in the open market. While existing open markets such as Gmarket, 11th Street, and so on are suffering from profitability deterioration, Naver is attracting sellers based on low commission and powerful search engine. We would like to analyze the impact of Naver shopping on the national economy, especially on employment, in a situation where the market reaction to Naver's strength as a leader in online shopping is mixed. Research Design, Data, and Methodology - Through the demand inducing inter-industry analysis, we estimate the employment inducement effect by Naver shopping from its shopping transaction. In turn, through the supply inducing inter-industry analysis, we estimate the employment inducement effect by Naver shopping from its low commission and powerful search engine. For the purpose of inter-industry analysis, as of 2018, the most recently announced 2014 inter-industry table (extension table) from the Bank of Korea is used. Results - The results of this study are as follows. First, Naver Shopping is expected to generate 7.8 trillion won's trade in 2018, resulting in 244,225 of job inducement, and 158,598 of employment inducement. In addition, Naver Shopping is estimated to benefit KRW 213 billion to its sellers due to low commission and powerful search function, resulting in 8,667 of job inducement, and 5,655 of employment inducement. Second, in terms of job inducement and employment inducement due to Naver Shopping's trade, transportation, business support service, information and communication, broadcasting, restaurants and lodging were ranked. Third, in terms of job inducement and employment inducement due to Naver Shopping's low commission and powerful search function, restaurants and hospitality, f/b and cigarette manufacturing, construction, and transportation equipment manufacturing were ranked. Conclusions - The number of job inducement resulting from low commission and powerful search engine of Naver shopping in 2018 was 8,667 (3.7% of 244,225, which was caused by transaction in Naver shopping in 2018), and employment inducement was 5,655 (3.7% of 158,598, which was caused by transaction in Naver shopping in 2018), which can be considered as additional employment impacts of Naver Shopping compared to the other online shopping operators.

• Journal of Korean Society of Transportation
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• v.20 no.4
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• pp.135-150
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• 2002

The basic assumption of analytical Dynamic Traffic Assignment models is that traffic demand and network conditions are known as a priori and unchanging during the whole planning horizon. This assumption may not be realistic in the practical traffic situation because traffic demand and network conditions nay vary from time to time. The rolling horizon implementation recognizes a fact : The Prediction of origin-destination(OD) matrices and network conditions is usually more accurate in a short period of time, while further into the whole horizon there exists a substantial uncertainty. In the rolling horizon implementation, therefore, rather than assuming time-dependent OD matrices and network conditions are known at the beginning of the horizon, it is assumed that the deterministic information of OD and traffic conditions for a short period are possessed, whereas information beyond this short period will not be available until the time rolls forward. This paper introduces rolling horizon implementation to enable a multi-class analytical DTA model to respond operationally to dynamic variations of both traffic demand and network conditions. In the paper, implementation procedure is discussed in detail, and practical solutions for some raised issues of 1) unfinished trips and 2) rerouting strategy of these trips, are proposed. Computational examples and results are presented and analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5135-5142
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• 2011

A flexible mechanism is proposed in this paper to improve the dynamic response performance of a traffic flow control system in an urban area. The roads, vehicles, and traffic control systems are all modeled as intelligent systems, wherein a wireless communication network is used as the medium of communication between the vehicles and the roads. The necessary sensor networks are installed in the roads and on the roadside upon which reinforcement learning is adopted as the core algorithm for this mechanism. A traffic policy can be planned online according to the updated situations on the roads, based on all the information from the vehicles and the roads. This improves the flexibility of traffic flow and offers a much more efficient use of the roads over a traditional traffic control system. The optimum intersection signals can be learned automatically online. An intersection control system is studied as an example of the mechanism using Q-learning based algorithm, and simulation results showed that the proposed mechanism can improve the traffic efficiency and the waiting time at the signal light by more than 30% in various conditions compare to the traditional signaling system.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.468-479
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• 2016

In order to supply power to online monitoring systems that are attached to high voltage catenary or overhead wires, a wireless power transfer system is required that is able to transmit power over the insulation gap. Such wireless power transfer systems have transmitter and receiver coils that have diameters of over 10cm. This paper focused on an investigation of the sources of loss in the coils when the coils are fabricated using printed circuit board technology. Using finite element simulation results, it has been shown that the dielectric loss in the substrate was the dominant source of the total loss. It has been demonstrated that the selection of a proper dielectric material was the most critical factor in reducing the loss. For further reduction of the loss, the distributed tuning capacitor method and the slotting of the inter-turn spaces have been proposed. For the evaluation of the proposed methods, four coils have been fabricated and their equivalent series resistances and quality factors were measured. Measured quality factors were greater than 300, which means that these devices will be helpful in achieving high coil-to-coil efficiency.