• Journal of the Korean earth science society
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• v.31 no.3
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• pp.259-266
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• 2010

High school students' understanding hierarchy of astronomical concepts and an individual student's knowledge state are analyzed by using the knowledge space theory that allows one to infer an individual's entire knowledge on a subject based on fragmentary information coming from that student's answers. The hierarchy of astronomical space concepts is: spatial position$\ll$spatial reasoning$\ll$spatial variation. In addition, an analysis of assessment materials using the knowledge space theory shows not only the relationship of assessment questions but also the knowledge state of individual students, which the current evaluation method is not able to reveal. Therefore, the assessment analysis of this study using the knowledge space theory becomes critically instrumental in providing information of an instructional differentiation amenable to individual learners for deciding their level of understanding and selecting suitable curriculum.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.9
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• pp.685-691
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• 2003

This work describes a 3 V 12b 100 MS/s CMOS digital-to-analog converter (DAC) for high-speed communication system applications. The proposed DAC is composed of a unit current-cell matrix for 8 MSBs and a binary-weighted array for 4 LSBs, considering linearity, power consumption, chip area, and glitch energy. The low-glitch switch driving circuit is employed to improve the linearity and the dynamic performance. Current sources of the DAC are laid out separately from the current-cell switch matrix core. The prototype DAC is implemented in a 0.35 urn n-well single-poly quad-metal CMOS technology. The measured DNL and INL of the prototype DAC are within $\pm$0.75 LSB and $\pm$1.73 LSB, respectively, and the spurious-free dynamic range (SFDR) is 64 dB at 100 MS/s with a 10 MHz input sinewave. The DAC dissipates 91 mW at 3 V and occupies the active die area of 2.2 mm ${\times}$ 2.0 mm.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.4
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• pp.25-35
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• 2002

This work describes an 8b 200MHz time-interleaved subranging analog-to-digital converter (ADC) based on a single-poly digital CMOS process. Two fine ADCs for lower digital bits of the proposed ADC employ a time-sharing double-channel architecture to increase system speed and a new reference voltage switching scheme to reduce settling time of the reference voltages and chip area. The proposed intermeshed resistor string, which generates reference voltages for fine ADCs, improves linearity and settling time of the reference voltages simultaneously. The proposed sample- and-hold amplifier(SHA) is based on a highly linear common-drain amplifier and passive differential circuits to minimize power consumption and chip area with 8b accuracy and employs input dynamic common mode feedback circuits for high dynamic performance at a 200MHz sampling rate. A new encoding circuit in a coarse ADC simplifies the signal processing between the coarse ADC and two successive fine ADCs.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.149-152
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• 2010

본 논문은 지구공간에 존재하는 다양한 공간정보를 이용하여 도로 및 철도 계획과 공사를 위한 최적노선을 선정하는 기법에 관한 새로운 연구이다. 사람과 물자를 수송하는데 있어서 가장 기본적인 공공교통시설인 도로 및 철도를 건설하기 위하여 초기에 가장 중요한 결정이 바로 최적노선결정이므로 환경파괴를 최대한으로 감소시키고 그 기능을 충분히 발휘할 수 있도록 대상 지역의 여러 가지 조건을 고려하여 가장 적합한 노선의 위치를 결정하여야 한다. 3차원 지형 환경의 공간영상콘텐츠는 국토계획 및 통신설비계획, 철도건설, 시공, 입체적인 유비쿼터스 도시 구현, 안전 및 방재 등에서 많은 요구와 그 중요성이 크게 부각되고 있다. 현재 지리정보 기반의 2차원적인 지도정보와 시설정보를 다차원의 도시공간으로 재현하기 위하여 기존의 등고선을 이용한 DEM 방식은 많은 한계를 가지고 있으며, 특히, 철도와 같은 노선 폭이 좁고 길이가 길어서 궤적 관리가 어려운 작은 구조물의 경우에는 그 고도모델이 무시되기 쉬우므로, 레이저 측량 기술을 이용한 공간대상물에 대한 높은 정확도 취득이 크게 필요한 실정이다. 본 연구에서는 원격탐사 영상 Data를 중심으로 하는 정사보정하고 이에 매칭 할 수 있는 수치 지도 벡터와의 통합 및 전환으로 다차원 공간에서 건물 모델의 생성과 다양한 활용을 제시하는 것을 연구목적으로 하였고, 연구방법으로는 기존의 이미 취득한 2차원적인 평면사진을 지상 기준점에 의하여 정밀기하보정을 하여 얻은 사진영상자료를 이용하여 3차원 공간정보로 구성하기 위해서는 동일지역에 대한 수준 측량결과인 높이 데이터를 매칭하여야 하므로, 항공기에 탑재한 센서로 모든 대상지에 대한 지형지물의 고밀도의 높이 값을 획득하여 위치보정 작업 후에 3D로 매칭할 수는 방법을 연구하여 실험하도록 하였다 또한 본 연구에서는 연구대상지역의 지형조건, 기존 노선과의 비교, 토지이용, 지형경사, 사면방향, 지가 등을 분석하여 각각의 경중률을 고려한 후 선택된 후보노선들을 비교분석함으로서 최적노선을 선정하고자 하였다.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.891-899
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• 2010

The purpose of this study is to estimate economic value of forest landscape function using conditional logit model, applied by Choice Experiment. For the study, we have chosen attributes and levels of forest landscape. In specific, topographical forest type, forest type, forest density, recreational factor (side trip, accessibility of valley) and WTP were included in attributes. Based on factors, we have made 48 choice sets with Balanced and Orthogonal form using SAS 9.1. The efficiency of questionnaire was 6.02 (D-Error: 0.1) and choice set and socio-economic variable were selected. In order to reduce cognitive load of respondent, 96 choice sets were divided into 4 types in questionnaire so that respondent could respond to 12 choice sets respectively. Population was citizens from 7 metropolitan cities including Seoul, and the interview survey was conducted to find out average annual WTP per household for the total 280 interviewees. As a result, In the Non-ASC model, Mcfadden' ${\rho}$ had 0.21, and Log Likelihood: -2,631. Average annual WTP per household for forest landscape was 266,723 Won(Korean currency).

• Journal of Korea Game Society
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• v.3 no.1
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• pp.74-85
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• 2003

If the game characters in the cyber world speak the same dialogues as in the real world, it will give game players more fun and realism. And game players are more and more immersed into the cyber space. However, we observed that only simple and primitive dialogues are used at the market places in most MMORPGS. We introduce personality psychology theory for generating the personality of NPC in MMORPG. And we suggest how to make a conversation between PC (Playable Character) and NPC (Non - Playable Character) according to 'Extroversion - Introversion dimension' and 'Neuroticism dimension'. And we implement the personality dialogue generation program, which is composed of two parts. One is for generating personality, and the other for making dialogue. Personality generator can set a NPC's personality automatically, and Dialogue Maker can control the dialogue styles, quantities, and characteristics of NPC. Thus, the program implemented in this paper can help game designer and scenario writer to make game characters easily. The approach in this paper can be applied to generate various game characters and used to represent agents and avatars of real-time animation.

• Journal of Korea Game Society
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• v.8 no.4
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• pp.17-27
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• 2008

This study has made an in-depth analysis of the 'Puzzle System' which is a characteristic structural unit of the Adventure Game, and concentrates on the mechanism where the experience arouses in the player a 'desire (quasi-need) to finish' that leads to one's immersion and engagement in the game. In the course of conducting this study, documentary records were consulted and also this writer personally played video games to learn the component elements and fundamental characteristics of the Adventure Games and to experience how the player was immersed in the game. Thus, the Puzzle System in the Adventure Game was defined and an analysis was made of the structure and course of play where the puzzle part and the narrative part within the system organically interacted between them in the system. In order to confirm the formation and effects of 'desire to finish' shown in the hypothetic assumptions, two experiment-purpose game units were produced, one with dramatic cut scenes and the other without them, so that differences between them could be found. I also conducted an experiment to learn the generation and effect of the 'desire to finish' of the Puzzle elements by using different games with a varying degree of difficulty.

• Journal of Korea Game Society
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• v.10 no.4
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• pp.15-22
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• 2010

The purpose of this research is to analyze players' emotion pattern for conducting a quest in Role Playing Game(RPG). We have rebuilt up the action and content of gameplay related to category to set up five action classes of game players based on the literature review about the human behavior classification. Moreover, Mabinogi game includes the composition of various quests by story-centered expanse. We classified the quest structure of the tutorial mode, initial state, of its game into the cognitive action. We build the model of the correlation between cognitive behavior patterns of gameplay and emotions derived from targeting ten novices. The result of this research reveals that gameplayers' stimulus levels are identified to emotion pattern. It is enable to grope to concrete the design of the quest and the level in a specified state. Moreover, players' emotion variation is indicated to the type of expression of fun elements. We expect to use a device to induce the curiousness and the challenge for conducting the higher goal of game in the whole.

• Korean Journal of Social Welfare
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• v.62 no.4
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• pp.5-32
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• 2010

Although social work practice skills are one of the important components of social work practice, research on social work practice skills has been very scarce. It seems that the reason might be a lack of standardized instruments used to measure social work practice skills. The purpose of this study is to validate a Korean version of the Practice Skills Inventory(PSI) developed by O'Hare and colleagues. The PSI is the only instrument developed in the field of social work to measure the frequency of social work practice skills that social workers use. A total of 310 social workers working in medical or mental health field were participated in this study. A result of confirmatory factor analysis showed that the Korean version of the PSI is composed of 4 factors like its english version. The Korean version of the PSI was also reliable and valid. Implications for social work research, practice and education are provided.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.725-733
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• 2012

MPEG and VCEG have constituted a collaboration team called JCT-VC(Joint Collaborative Team on Video Coding) and have been developing the HEVC(High Efficiency Video Coding) standard. The next generation video coding standard HEVC shows higher compression rate compared with the H.264/AVC standard, but the encoder computational complexity of the HEVC encoder is significantly high. In order to reduce this computational complexity in the HEVC encoder, a fast prediction unit decision is proposed. The proposed fast prediction unit decision method reduces the encoder complexity by skipping the remaining prediction units if the current prediction unit does not have any non-zero quantized transform coefficient. The proposed method reduces the encoder computational complexity by 50.3% comparing with HM6.0 but it maintains the same level of coding efficiency.