쇼핑센터에서 Armature 분석을 통한 상업적 전략에 관한 연구

김형중(Kim, Hyeongjung) 한국실내디자인학회 2012 한국실내디자인학회논문집 Vol.21 No.1

One hand shopping center provides a public space for people, the other hand it is a place for commercial purpose. Although it gives an entertainment, eating and shopping places to people nowaday, owners and tenants aim to make profit from it. According to this demand designers should plan a shopping center for a comfortable place for eating, shopping and playing and they make shops and retails to increase sales by exposing those to more people at the same time. For successful shopping center architects are requested an approach with commercial strategy that shopping center raises exposure of retails and makes stay costumers longer and visit more frequently. Recently space is regarded as a mean of marketing, so-called “place marketing”, because it can influence on brand image and improves the image of product. Therefore, it need to be approached with commercial consideration. Analyzing the armature this study will take a look at spatial strategies in shopping centers which especially the Jerde Partnership, one of influential firms on commercial space, designed. And it will examine how spatial strategies can be applied to commercial strategies in relation to customer information process(exposure-attention-interest-comprehension-memory) which marketers are using in advertisement for marketing and what kind of role spatial strategies can be. This study is to be basic considerations when a shopping center project will be planned.

집객시설과 노출시간에 따른 도심 엔터테인먼트형 복합상업시설(UEC)의 특징에 관한 연구

김형중(Kim, Hyeongjung) 한국실내디자인학회 2013 한국실내디자인학회논문집 Vol.22 No.1

The change of shopping environment created new emerging type of shopping center after 1990"s, Urban Entertainment Center(UEC) in northen America. One hand traditional shopping center was retail-centered, the other hand UEC is entertainment-centered and offers the trinity of synergy. Each components, that are retail, dining and entertainment, play a role of drawing people, extending duration of visiting and making people revisit then the synergy makes commercial profit in shopping center. As northen America many of shopping centers with complex have been built in Korea since 2000 and some projects is planning by the change of shopping environment and regenerating urban. Although the term of "UEC" is used in Korea, it seems to be added entertainment facilities to shopping center without considering on commercial strategy. This study will take a look at mix and duration of visit which ULI stresses in UEC development and comparing with those of Yongsan Station and Chyeongrangri Station which are built recently in seoul, it will get characters and situation of these UECs. Finally, the analysis is to be used as a planning data in UEC development.

A Study on the Degradation of In-Ga–Zn-O Thin-Film Transistors Under Current Stress by Local Variations in Density of States and Trapped Charge Distribution

Sungju Choi,Hyeongjung Kim,Chunhyung Jo,Hyun-Suk Kim,Sung-Jin Choi,Dong Myong Kim,Park, Jozeph,Dae Hwan Kim IEEE 2015 IEEE electron device letters Vol.36 No.7

<P>Thin-film transistors using In-Ga-Zn-O (IGZO) semiconductors were evaluated under current stress by applying positive voltages to the gate and drain electrodes. Initially, the transfer characteristics exhibit identical threshold voltages (V-T) when the source and drain electrodes are interchanged during measurement (forward and reverse V-DS sweep). However, as stress time increases, larger shifts in V-T are observed under forward V-DS sweep than under reverse V-DS sweep conditions. Subgap states analyses based on the photoresponse of capacitance-voltage (C-V) curves suggest that local annihilation of donor-like traps occurs near the drain electrode. Hump-like features are clearly observed in the C-V curves collected between the drain and gate electrodes, while they do not appear in the C-V data obtained between the source and the gate. Based on the above, a local charge trapping model is introduced in order to interpret the device degradation. In this model, the major carrier electrons are trapped more abundantly near the source electrode due to the presence of a Schottky junction between IGZO and the source/drain electrodes.</P>

The Effect of Gate and Drain Fields on the Competition Between Donor-Like State Creation and Local Electron Trapping in In–Ga–Zn–O Thin Film Transistors Under Current Stress

Sungju Choi,Hyeongjung Kim,Chunhyung Jo,Hyun-Suk Kim,Sung-Jin Choi,Dong Myong Kim,Park, Jozeph,Dae Hwan Kim IEEE 2015 IEEE electron device letters Vol.36 No.12

<P>Thin-film transistors using In-Ga-Zn-O (IGZO) semiconductors were evaluated under positive bias stress with different gate and drain voltages (VGS and VDS, respectively). The transfer characteristics with respect to stress time were examined, focusing on the threshold voltage (V-T) values obtained when the source and drain electrodes are interchanged during readout (forward and reverse VDS sweep). The V-T values shift toward either negative or positive values during stress, while transitions from negative to positive shifts are also observed. The negative V-T shift under positive bias stress is interpreted to occur by the generation of donor-like states related to ionized oxygen vacancies. On the other hand, positive V-T shifts result from the trapping of electrons near the IGZO/gate insulator interface. The transitions from negative to positive V-T shift are believed to result from the local electron trapping mechanism that gradually takes over donor-like state creation. From the experimental results and TCAD device simulation, it is suggested that a competition occurs between donor-like state creation and electron trapping. The relative magnitudes of the VGS and VDS fields determine which mechanism dominates, providing an analytical insight for the design of stable devices for driving transistors in AMOLED backplanes.</P>

Dual-Sweep Combinational Transconductance Technique for Separate Extraction of Parasitic Resistances in Amorphous Thin-Film Transistors

Sungwoo Jun,Hagyoul Bae,Hyeongjung Kim,Jungmin Lee,Sung-Jin Choi,Dae Hwan Kim,Dong Myong Kim IEEE 2015 IEEE electron device letters Vol.36 No.2

<P>We report a dual-sweep combinational transconductance technique for separate extraction of parasitic source (R<SUB>S</SUB>) and drain (R<SUB>D</SUB>) resistances in thin-film transistors (TFTs) by combining forward and reverse transfer characteristics. In the proposed technique, gate bias-dependent total resistance [R<SUB>TOT</SUB> (V<SUB>GS</SUB>)] and degradation of the transconductance due to the parasitic resistance at the source terminal during the dual-sweep characterization are employed. Applying the proposed technique to amorphous oxide semiconductor TFTs with various combinations of channel length (L) and width (W), we successfully separated R<SUB>S</SUB> and R<SUB>D</SUB>. A model for the W- and L-dependences of the extracted parasitic resistances is also provided.</P>

Physical Origins and Analysis of Negative-Bias Stress Instability Mechanism in Polymer-Based Thin-Film Transistors

Jaewook Lee,Jaeman Jang,Hyeongjung Kim,Jiyoul Lee,Bang-Lin Lee,Sung-Jin Choi,Dong Myong Kim,Dae Hwan Kim,Kyung Rok Kim IEEE 2014 IEEE electron device letters Vol.35 No.3

<P>The physical origins of the negative-bias stress (NBS) instability in polymer-based thin-film transistors have been characterized. Through the quantitative analysis by TCAD simulation for the NBS time-dependent experimental results, the threshold voltage (V<SUB>T</SUB>)-shift by sub-bandgap density-of-states redistribution forms 70% and 78% for the measured total V<SUB>T</SUB>-shift while V<SUB>T</SUB>-shift by gate oxide charge trapping only takes 30% and 22% at NBS time of 3000 and 7000 s, respectively. In addition, the increase of source/drain Schottky contact resistance (R<SUB>SD</SUB>) is the main reason for NBS-induced on -current (I<SUB>ON</SUB>) degradation.</P>

Fully Transfer Characteristic-Based Technique for Surface Potential and Subgap Density of States in p-Channel Polymer-Based TFTs

Jaewook Lee,Sungwoo Jun,Jaeman Jang,Hagyoul Bae,Hyeongjung Kim,Jong Won Chung,Sung-Jin Choi,Dae Hwan Kim,Jiyoul Lee,Dong Myong Kim IEEE 2013 IEEE electron device letters Vol.34 No.12

<P>We report a fully subthreshold current-based technique for characterization of subgap density of states [DOS:g(E)] with consistent mapping of the surface potential (ψ<SUB>S</SUB>) in p-channel polymer-based thin-film transistors (PTFTS). Initially, we propose a technique for extraction of the DOS over the bandgap using the gate voltage (V<SUB>GS</SUB>)-dependent ideality factor [m(V<SUB>GS</SUB>)] from the transfer characteristics of the PTFTs under subthreshold operation. We also propose a technique for a consistent nonlinear mapping of V<SUB>GS</SUB> to the subgap energy level by converting m(V<SUB>GS</SUB>) to ψ<SUB>S</SUB>. Through combining the two methods, the exponential tail and deep g(E) are obtained to be N<SUB>TD</SUB>=1·1×10<SUP>17</SUP> [eV<SUP>-1</SUP>·cm<SUP>-3</SUP>], kT<SUB>TD</SUB>=0·035 [eV], N<SUB>DD</SUB>=9·8×10<SUP>16</SUP> [eV<SUP>-1</SUP>·cm<SUP>-3</SUP>], and kT<SUB>DD</SUB>=0·80 [eV] over the bandgap.</P>

Multiuser Diversity based Adaptive Scheduling Scheme for OFDMA systems

Giang Hai Tong,HyeongJung Kim,Subodh Pudasaini,Seokjoo Shin 한국차세대컴퓨팅학회 2012 한국차세대컴퓨팅학회 논문지 Vol.8 No.1

OFDMA 기반 다중사용자 시스템에서는 상향링크 피드백 형식으로 기지국에 보고되는 각 사용자의 채널 품질 정보(CQI)를 기반으로 사용자를 선택한다. 이를 위해 상향링크 채널의 오버헤드가 많이 요구되는 상세한 피드백 정보를 이용하거나 오버헤드는 적지만 불충분한 CQI 정보를 이용하는 방식은 상호 trade-off 관계에 있기 때문에 시스템 처리률을 최적화시키기에 어려움이 있다. 따라서 이 문제를 해결하기 위해, best-M 스케줄링 기법이 제안되었다. best-M 기법에서는 모든 서브채널에 대해서 CQI를 전송하는 대신에 M 서브채널의 CQI 만을 기지국으로 전송함으로써 상향링크 오버헤드를 줄일 수 있게 된다. 본 논문에서는 시스템의 처리량을 더 향상시키기 위해서, 능동적 사용자들의 수를 기반으로 M을 적응적으로 계산하는 적응적 best-M 피드백 스케줄링 방식을 제안하였다. 컴퓨터 시뮬레이션을 통한 제안 방식의 성능 분석 결과로부터 제안된 기법은 상향링크 오버헤드를 현저히 줄이면서 향상된 하향링크 처리률을 제공할 수 있음을 확인하였으며, 특히 best M 방식과 비교할 경우 동일 시스템에서 더 많은 동시 사용자를 지원할 수 있음을 확인하였다. 또한, 본 연구에서는 총 피드백 오버헤드 제한 조건에 따른 시스템 최적 처리률을 얻기 위한 중요 동작 포인트를 얻을 수 있었다.