• Journal of IKEEE
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• 제23권1호
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• pp.193-199
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• 2019

In this study, we have proposed a floating metal guard ring structure based on TCAD simulation in order to enhance the breakdown voltage characteristics of gallium oxide ($Ga_2O_3$) vertical high voltage switching Schottky barrier diode. Unlike conventional guard ring structures, the floating metal guard rings do not require an ion implantation process. The locally enhanced high electric field at the anode corner was successfully suppressed by the metal guard rings, resulting in breakdown voltage enhancement. The number of guard rings and their width and spacing were varied for structural optimization during which the current-voltage characteristics and internal electric field and potential distributions were carefully investigated. For an n-type drift layer with a doping concentration of $5{\times}10^{16}cm^{-3}$ and a thickness of $5{\mu}m$, the optimum guard ring structure had 5 guard rings with an individual ring width of $1.5{\mu}m$ and a spacing of $0.2{\mu}m$ between rings. The breakdown voltage was increased from 940 V to 2000 V without degradation of on-resistance by employing the optimum guard ring structure. The proposed floating metal guard ring structure can improve the device performance without requiring an additional fabrication step.

• The Korean Journal of Archival Studies
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• 제46호
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• pp.5-44
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• 2015

This article purposes to define archival justice and suggest democratic modeling of the archive on the Truth and Reconciliation Committee (TRC), which is focused on victims of state violence. These purposes come from critical mind that the absence of framework of the records management for collective memory would cause incorporation of TRC archives into mainstream archives systems in which voices of victims have been marginalized. This article intends to expand theoretical prospects of documentation of past affairs through applying humanistic and theoretical frameworks differently from institutional and policy approaches on restoration of collective memory. In order to do this, this article first considers archival justice as archives building in which state violence' victims are pivotal and then extracts theoretical frameworks for building the archives based on archival justice from recent discourses of post-colonial archives and community archives. As the next step, it criticizes current conditions of TRC archives in Korea on the basis of extracted theoretical frames and finally suggests realistic models in which each theoretical frame could be applied effectively into TRC archives that is focused on victims.

• Journal of Broadcast Engineering
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• 제24권1호
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• pp.48-57
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• 2019

The purpose of this study is to understand the intention of the inquirer from the single text type question in Goal-oriented dialogue. Goal-Oriented Dialogue system means a dialogue system that satisfies the user's specific needs via text or voice. The intention analysis process is a step of analysing the user's intention of inquiry prior to the answer generation, and has a great influence on the performance of the entire Goal-Oriented Dialogue system. The proposed model was used for a daily chemical products domain and Korean text data related to the domain was used. The analysis is divided into a speech-act which means independent on a specific field concept-sequence and which means depend on a specific field. We propose a classification method using the word embedding model and the CNN as a method for analyzing speech-act and concept-sequence. The semantic information of the word is abstracted through the word embedding model, and concept-sequence and speech-act classification are performed through the CNN based on the semantic information of the abstract word.

• Journal of the Korea Convergence Society
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• 제10권5호
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• pp.229-238
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• 2019

The purpose of this study is to understand in depth the gambling experiences of delinquent juveniles who have dropped out of school and analyze the content and meaning of gambling experiences. Thus, utilized a Giorgi's phenomenological research method. Data was gathered through in-depth interviews, and the gambling experiences of six youths who are under juvenile law protective disposition were examined through a four-step analytic process. From the results, 6 parent components and 18 sub-components were derived. That is, "the temptation of close gambling", "trapped in the bridle of gambling", "deterioration of life", "damaged of non-official networks relationship", "corruption of existence" and "attempts to escape gambling" were appeared. These results are meaningful because they have allowed researchers to identify the essential meaning and experiential structure of delinquents juvenile' gambling experiences outside of school, which has not been studied thus far. Further, this study has empirical value as its framework includes a joint analysis in terms of welfare and gambling addiction and focuses on a precarious population-delinquent juveniles who have dropped out of school. The results provide a foundation from which practical implications and policy alternatives for the prevention and treatment of gambling problems in delinquent juveniles dropped out of school.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제19권12호
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• pp.677-685
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• 2018

In construction, schedule management is the basic but important step, for the effective schedule management, the preparation of the reasonable schedule table should be prioritized. In the design stage, the optimal construction period can be selected through comparison of various conditions and construction methods considering weather conditions and site characteristics. But, At the planning phase, it is difficult to select the effective method and calculate the proper construction period by the basic data(D/B) analysis. In this paper, the construction method considering characteristics of each type and conditions of existing city was selected. For the reasonable duration calculation, we analyzed the unit schedule for RC method for open type and Shield TBM method for tunnel type. The normal project duration of construction assuming of 1,200m of extension and every 200m of ventilation was prepared by integrating each unit schedule. It was analyzed that it took 893 days for the open type and 616 days for the tunnel type. The results of this study will help to make type selection and normal project duration more easily in the planning phase. If it is linked to the design stage, it will be easy to estimate the process and construction cost.

• Clean Technology
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• 제27권2호
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• pp.182-189
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• 2021

The adsorption of disperse yellow 3 (DY 3) on granular activated carbon (GAC) was investigated for isothermal adsorption and kinetic and thermodynamic parameters by experimenting with initial concentration, contact time, temperature, and pH of the dye as adsorption parameters. In the pH change experiment, the adsorption percent of DY 3 on activated carbon was highest in the acidic region, pH 3 due to electrostatic attraction between the surface of the activated carbon with positive charge and the anion (OH^-) of DY 3. The adsorption equilibrium data of DY 3 fit the Langmuir isothermal adsorption equation best, and it was found that activated carbon can effectively remove DY 3 from the calculated separation factor (R_L). The heat of adsorption-related constant (B) from the Temkin equation did not exceed 20 J mol^-1, indicating that it is a physical adsorption process. The pseudo second order kinetic model fits well within 10.72% of the error percent in the kinetic experiments. The plots for Weber and Morris intraparticle diffusion model were divided into two straight lines. The intraparticle diffusion rate was slow because the slope of the stage 2 (intraparticle diffusion) was smaller than that of stage 1 (boundary layer diffusion). Therefore, it was confirmed that the intraparticle diffusion was rate controlling step. The free energy change of the DY 3 adsorption by activated carbon showed negative values at 298 ~ 318 K. As the temperature increased, the spontaneity increased. The enthalpy change of the adsorption reaction of DY 3 by activated carbon was 0.65 kJ mol^-1, which was an endothermic reaction, and the entropy change was 2.14 J mol^-1 K^-1.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• 제14권1호
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• pp.56-69
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• 2021

In this paper, the PV system with a link to the commercial system needs some advantages like small capacity, high power factor, high reliability, low harmonic output, maximum power operation of solar cell, and low cost, etc. as well as the properties of inverter. To transfer the PV energy of photovoltaic power generation system to the system and load, it requires PCS in both directions. The purpose of this paper is to confirm the stable power supply through the load leveling by presenting the PCS considering ESS of photovoltaic power generation. In order to achieve these purpose, 5 step process of operation mode algorithm were used according to the solar insolation amount and load capacity and the controller for charging/ discharging control was designed. For bidirectional and effective energy transfer, the bidirectional converter and battery at DC-link stage were connected and the DC-link voltage and inverter output voltage through the interactive inverter were controlled. In order to prove the validity of the suggested system, the simulation using PSIM was performed and were reviewed for its validity and stability. The 3[kW] PCS was manufactured and its test was conducted in order to check this situation. In addition, the system characteristics suggested through the test results was verified and the PCS system presented in this study was excellent and stronger than that of before system.

• (The) Korean Journal of Educational Psychology
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• 제26권4호
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• pp.1225-1248
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• 2012

The present study explored how ADHD assessment, identification, and diagnosis were conducted in research through an overview of research papers on ADHD in the last 10 years. The collected studies were categorized and analyzed by topics including data collection settings, assessment and identification, coexistence with other disabilities, considerable variables throughout evaluation, and biological basis. They were categorized and analyzed according to the identification methods, the number of assessment(s) and the number of informant(s). The results were as follows: First, the assessment and identifying studies on children with ADHD were excessively biased toward clinical settings. Second, the majority of the previous studies explored more the development or validation of tools for the assessment and identifying of ADHD than the other topics. Finally, a high preference for the use of a multiple assessment method in identifying ADHD was found. However, considering methodological aspects, there was a lack of practical application of multi-step process such as including a personal interview, reviewing school records or direct observing rating criteria. Considering these results, we discussed an urgent need for the diagnosis and identification guidelines of ADHD for teachers to effectively identifying ADHD children at schools. The implications of school-based ADHD assessment and diagnosis research were suggested.

• The Journal of Korean Philosophical History
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• 제32호
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• pp.337-370
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• 2011

The academic circle of the Qing Dynasty has seen a new trend, mostly based on Han-Hak through the event of the publication of "Sagojeyo" and sought a new change in the sector of Spring Autumn-Hak as well. This study is focused on understanding and evaluation of the developmental process of especially the traditional Spring Autumn-Hak view, among some views of "Sagojeyo" by the book. "Sagojeyo" does a critical analysis of Gongyang-Hak and Gokryang-Hak and the interpretation of "Spring Autumn" made by Song-Hak scholars, and which seems a kind of preparatory step to build up a new research methodology for Spring Autumn-Hak. "Sagojeyo" emphasizes the importance of "Jwacijeon" and also points out its weaknesses and strongly demands the acceptance of strengths "Gongyangjeon" and "Gokryangjeon" have in order to compensate such demerits. Even further, it tries to evaluate Spring Autumn-Hak of the Song Dynasty objectively and reasonably as possible with no prejudice. Such analysis attitude made it possible for Spring Autumn-Hak to get a new turning point starting from the publication of "Sagojeyo". The new research methodology that comprehensively judges historical research and fidelity discourse could be one of important achievements discovered in the Han-Hak-centered academic circle in the early Qing Dynasty.

• MARITIME LAW REVIEW
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• 제29권2호
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• pp.115-144
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• 2017

The impact of the global financial crisis, which began in the United States in 2007, had a major impact on the domestic shipping and shipbuilding industries. In this regard, the domestic shipyard has established an order-taking strategy in several ways as an alternative to lowering the amount of construction of commercial vessels due to deterioration of the shipping industry, and selected industrial sector was the offshore plant sector. However, the domestic shipyard has under performed the offshore plant in order to just increase sales and secure work without any risk analysis for EPC contracts. As a result, the shipyard has been charged more than the initial contract price with the offshore plant contractor, or the shipyard has become a legal issue requiring payment of liquidated damages due to delays in delivery of the product. The main legal disputes are caused by the thorough risk analysis and the inexperience of process control that can occur during offshore plant construction. and In particular, there is no sufficient review of the unequivocal provisions in the contract as an element of risk management. There is no human resource to review these contractual clauses. Therefore, this study identifies the existence of specific risks that could lead to delays in offshore plant construction, and examined the existence of any unequivocal clauses in contracts for offshore plant construction. and also discussed how the toxic clause applies to the actual parties and how the concrete risk factors in the construction contracts are transferred and expressed by referring to the interviews with the project manager of the domestic shipyard and the previous research. As a result, This paper examined the legal liability of the contracting parties regarding delayed delivery of the products due to the offshore plant construction contract. And to improve the domestic shipbuilding industry.