자동차 시트에서 자동으로 좌우 엉덩이 부분 독립제어가 가능한 Air Bladder를 이용한 척추 골반 균형 개선 효과에 대한 연구

최우진(Woojin Choi),여성윤(Seongyun Yeo),강구창(Guchang Kang),김성훈(Sunghoon Kim),손문준(Moonjun Sohn) 한국자동차공학회 2022 한국 자동차공학회논문집 Vol.30 No.12

자동차 시트에서 자동으로 좌우 엉덩이 부분 독립제어가 가능한 Air bladder를 이용한 척추 골반 균형 개선 효과에 대한 연구

최우진(Woojin Choi),여성윤(Seongyun Yeo),강구창(Guchang Kang),김성훈(Sunghoon Kim),손문준(Moonjun Sohn) 한국자동차공학회 2022 한국자동차공학회 부문종합 학술대회 Vol.2022 No.6

This study is to investigate changes in the drivers spinal pelvis posture between imbalanced and balanced sitting in the smart car seat using radiographic parameters. A smart car seat capable of balancing the air bladders was used to automatically measure the pressure difference between the participants hips and balance them on IoT based controller. When comparing x-ray imaging of balanced seating with initial standing versus unbalanced seating for a total of 32 applicants, the shoulder and pelvic height differences were statistically significantly reduced during a 25-minute balanced seating (p=0.0026, 0.0013 versus p=0.0188, 0.0105, respectively). There was no statistically significant difference in radiographic changes between initial and 25-minute unbalanced seating. The use of smart car seats equipped with air bladder allows drivers with spinal, shoulder, and pelvic imbalance to sit balanced while driving, thereby reducing the progress of driving-related-spine diseases and ultimately contributing to improved driving comfort.

팝업 개념을 적용한 식공간의 유형적 특징에 관한 연구 -서울시 경의선 숲길 일대 사례를 중심으로-

최우진 ( Choi Woojin ),정강화 ( Chung Gangwha ) 한국공간디자인학회 2022 한국공간디자인학회논문집 Vol.17 No.7

(연구배경 및 목적) 현대 사회의 소비자는 이성보다는 감성을, 상품의 기능이나 효율보다는 브랜드의 이미지와 가치가 소비 행위의 전 과정에서 감성적 경험을 원하고 있다. 이에 따라 소비 공간에서 행해지는 모든 경험이 소비의 대상이 된다. 이러한 감성적 공간 전략에서 2010년대에 등장한 팝업(pop-up)개념은 팝업스토어(pop-up store)로 도입되었고 가치소비와 취향소비의 행태가 두드러지면서 팝업 개념을 적용한 식공간이 등장했다. 이에 따라 최근 경의선 숲길 일대를 중심으로 팝업 개념을 적용한 새로운 형태의 식공간이 생겨났고 이러한 배경으로 본 연구는 서울시 경의선 숲길 일대를 중심으로 빈번하게 나타나는 팝업식공간을 사례분석하였다. 이를 바탕으로 팝업 식공간의 유형과 그에따른 특징을 도출하여 향후 식공간에서 다채로운 팝업 콘텐츠의 활용도를 높이는데 의의가 있다. (연구방법) 본 연구는 팝업 식공간 유형을 분류하기 위해 팝업 식공간 사례를 팝업 개념 요소를 통해 분석하였다. 이를 위해 팝업의 개념과 요소에 대한 이론적 고찰을 확립하였고 본 연구의 목적에 맞게 팝업 식공간 요소를 정리하였다. 이후 선행논문을 통해 팝업 식공간 요소 6가지를 도출하여 이를 바탕으로 팝업 공간이 다발적으로 나타나고 있는 경의선 숲길 일대의 팝업 식공간 사례 8곳을 선정하여 사례 분석하였다. (결과) 그 결과 팝업 식공간 사례에서 나타난 식공간 유형을 본 연구에서는 주기에 따라 3가지의 형태로 분류할 수 있었다. 브랜드 팝업 공간으로 공간 임대나 건물 임차를 통해 한 달에서 두 달 정도의 단기간 팝업 식공간을 운영하는 단독팝업형, 기존 영업 매장 공간을 집약적으로 사용하며 통일된 분위기의 팝업 콘텐츠를 기획 및 운영하여 식공간에 변화를 주는 변환팝업형, 기존 영업 매장에서 불특정 주기에 따라 다양한 장르의 팝업 콘텐츠를 기획, 운영하는 편집팝업형으로 분류할 수 있었다. (결론) 본 논문에서는 현재 명확한 정체성 없이 등장하고 있는 팝업 식공간이 다양한 팝업 콘텐츠와 다중(多重) 공간으로 변화하고 있음을 확인하고 팝업 식공간의 유형을 분류하여 유형적 특징을 도출했다. 사례분석 결과, 팝업 개념을 적용한 식공간이 가진 정체성과 다양한 장르의 변화를 체험하려는 시도가 교차하면서 식공간 영역에서 팝업 개념의 활용도는 높아질 것으로 판단된다. 그러나 경의선 숲길 일대를 중심으로 팝업 개념을 적용한 식공간이 빈번하게 등장하고 있다는 점에서 지역적 특성의 한계가 보인다. 본 연구를 기반으로 자리 잡고 있는 팝업 식공간의 중요성이 인식되어 향후 식공간의 다양한 팝업 콘텐츠 기획이 시도되기를 바란다. (Background and Purpose) Consumers in modern society want emotional experience rather than rationality and focus on brand image and value rather than product function and efficiency. Consequently, all experiences conducted in the consumption space are subject to consumption. The pop-up concept, which appeared in the 2010s with this sentimental space strategy, was introduced in pop-up stores, and the behavior of value consumption and preference consumption was conspicuous; eating space, which applied the pop-up concept, also appeared. A new form of pop-up eating space was recently created around the Gyeongui Line Forest Road. Against this background, this study analyzed pop-up eating spaces frequently found around the Gyeongui Line Forest Road in Seoul. Based on this, it is meaningful to determine the type of pop-up eating space and its characteristics and to increase the utilization of various pop-up contents in the future. (Method) In order to categorize pop-up eating space types, this study analyzed pop-up eating space examples through pop-up conceptual elements. To this end, we established a theoretical consideration of pop-up concepts and elements and organized pop-up spatial elements according to the purpose of this study. Afterward, six pop-up eating space elements were derived from a previous paper, and eight pop-up eating space cases were selected from the Gyeongui Line Forest Road, where pop-up spaces are frequently observed; subsequently, the collected data were analyzed. (Results) The types of eating spaces that appeared in pop-up eating space cases were classified into three forms according to the period in this study. It can be categorized as a single pop-up type that operates a pop-up eating space for a short period of 1-2 months through space rental or building rental, a conversion pop-up type that plans and operates pop-up contents with a unified atmosphere, and an edit pop-up type that plans and operates pop-up contents of various genres according to unspecified cycles. (Conclusions) This study confirmed that the pop-up eating space currently appearing without a clear identity is changing into a variety of pop-up contents and multiple spaces, and the types of pop-up eating spaces are classified to derive typographical features. As a result of the case analysis, it is judged that the utilization of pop-up concepts in the eating space area will increase as attempts to experience the identity of the eating space with various genre changes intersect. However, regional characteristics observed in the selected cases are limited because there are frequent pop-up restaurants around the Gyeongui Line Forest Road. It is hoped that, through this study, the importance of pop-up eating spaces will be recognized, and various pop-up content planning of eating spaces will be attempted in the future.

수직적 브랜드확장 평가에 대한 확장방향과 권력거리신념의 상호작용효과

최우진(Choi, Woojin),나은정(Na, Eunjung),이학식(Lee, Haksik) 한국마케팅학회 2017 마케팅연구 Vol.32 No.1

수직적 브랜드확장은 상향확장과 하향확장으로 나뉘는데, 이 방향성은 확장브랜드의 가치 뿐 아니라 모브랜드의 가치에도 큰 영향을 미친다. 그러나 아직까지 브랜드확장 방향에 따른 소비자 평가에 어떤 변수들이 영향을 미치는가에 대한 연구는 부족한 실정이다. 이러한 선행연구의 한계에 착안하여 본 연구는 권력거리신념(power distance belief) 개념을 도입, 수직적 브랜드확장의 방향과 소비자 권력거리신념이 소비자의 확장브랜드 및 모 브랜드 평가에 어떤 영향을 미치는지를 규명하고자 하였다. 연구결과의 요약과 시사점은 다음과 같다. 첫째, 소비자 권력거리신념은 확장방향이 확장브랜드 평가에 미치는 영향을 조절하는 것으로 나타났다. 즉, 상향확장시 권력거리신념이 높을수록 소비자는 확장브랜드에 대해 부정적으로 평가한다는 것을 확인하였다. 둘째, 브랜드확장 자체에 대한 평가 및 모브랜드 평가 또한 확장방향과 권력거리신념에 따라 다른 것으로 나타났다. 상향확장(vs. 하향확장)의 경우 권력거리신념이 높은 소비자일수록 저가 브랜드의 상위시장 진입에 대해 부정적으로 인식, 모브랜드에 대해 더 부정적으로 평가하였다. 따라서 상향확장시 기업은 확장브랜드 뿐만 아니라 모브랜드에 대한 이미지가 훼손되지 않도록 소비자 권력거리를 감안, 이에 맞는 마케팅 전략을 수립하는 것이 필요할 것이다. The direction of vertical brand extension is one of the key decisions that firms must make. Stretching their brands either upward or downward will determine the position of an extended brand as well as of a parent brand. However, scant research has explored the factors influencing the effect of the direction of vertical brand extension on consumers’ attitudes toward the extension. To fill this gap in the literature, the current research examines how the direction of vertical brand extension and consumers’ power distance beliefs jointly influence consumers’ attitudes toward an extended and a parent brand. The results are as follows. First, consumers’ power distance beliefs interact with the direction of vertical brand extension to influence their evaluations of an extended brand. In the case of an upward extension versus a downward extension, as consumers’ power distance beliefs increase, their evaluations of an extended brand were negative. Second, consumers’ evaluations of a brand extension itself and of a parent brand depend on their power distance beliefs and the direction of brand extension. In an upward extension, consumers with higher power distance beliefs are more likely to perceive the entry of a lower-tier brand into an upper market as being negative, resulting in more negative evaluations of a parent brand. In conclusion, marketers would be wise to pay greater attention to the differences in consumers’ power distance beliefs in their target markets, and respond appropriately with differentiated marketing strategies.

사회적 반투명성을 활용한 온라인 그룹 학습 시스템 개발에 대한 연구

최우진(Woojin Choi),이문환(Moon-Hwan Lee) 한국디자인학회 2022 디자인학연구 Vol.35 No.4

A Method to Improve the Performance of Phase-Locked Loop (PLL) for a Single-Phase Inverter Under the Non-Sinusoidal Grid Voltage Conditions

칸 레이안,최우진,Khan, Reyyan Ahmad,Choi, Woojin The Korean Institute of Power Electronics 2018 전력전자학회 논문지 Vol.23 No.4

The phase-locked loop (PLL) is widely used in grid-tie inverter applications to achieve a synchronization between the inverter and the grid. However, its performance deteriorates when the grid voltage is not purely sinusoidal due to the harmonics and the frequency deviation. Therefore, a high-performance PLL must be designed for single-phase inverter applications to guarantee the quality of the inverter output. This paper proposes a simple method that can improve the performance of the PLL for the single-phase inverter under a non-sinusoidal grid voltage condition. The proposed PLL can accurately estimate the fundamental frequency and theta component of the grid voltage even in the presence of harmonic components. In addition, its transient response is fast enough to track a grid voltage within two cycles of the fundamental frequency. The effectiveness of the proposed PLL is confirmed through the PSIM simulation and experiments.

최신 산업동향을 고려한 공업단지 사용량 원단위 분석 연구

김기범,유영준,최우진,구자용,Kim, Kibum,Yu, Youngjun,Choi, Woojin,Koo, Jayong 대한상하수도학회 2017 상하수도학회지 Vol.31 No.5

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

An Improved Harmonic Compensation Method for a Single-Phase Grid Connected Inverter

칸 레이안,최우진,Khan, Reyyan Ahmad,Choi, Woojin The Korean Institute of Power Electronics 2019 전력전자학회 논문지 Vol.24 No.3

Grid-connected inverters should satisfy a certain level of total harmonic distortion (THD) to meet harmonics standards, such as IEEE 519 and P1547. The output quality of an inverter is typically degraded due to grid voltage harmonics, dead time effects, and the device's turn-on/turn-off delay, which all contribute to increasing the THD value of the output. The use of a harmonic controller is essential to meet the required THD value for inverter output under a distorted grid condition. In this study, an improved feedforward harmonic compensation method is proposed to effectively eliminate low-order harmonics in the inverter current to the grid. In the proposed method, harmonic components are directly compensated through feedforward terms generated by the proportional resonant controller with the grid current in a stationary frame. The proposed method is simple to implement but powerful in eliminating harmonics from the output. The effectiveness of the proposed method is verified through simulation using PSIM software and experiments with a 5 kW single-phase grid-connected inverter.

독립형 태양광 발전 시스템의 무정전 전력공급을 위한 시스템 용량 최적 선정에 관한 연구

김기영(Ki-Young Kim),최우진(Woojin Choi) 전력전자학회 2017 전력전자학술대회 논문집 Vol.2017 No.7

Design of the Multi-converter System for Fuel Cell Diagnosis and Load Leveling

Thanh-Tuan Nguyen(응웬탄두안),Woojin Choi(최우진) 전력전자학회 2013 전력전자학술대회 논문집 Vol.2013 No.11