A Feasible Sales Price Decision Model of Apartment Housing Units Considering the Market Price and Buying Power

Park, Hyesung,Lee, Donghoon,Kim, Sunkuk Informa UK (TaylorFrancis) 2016 JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEE Vol.15 No.2

An Alternative Hole Transport Layer for Both ITO- and Graphene-Based Organic Solar Cells

Park, Hyesung,Kong, Jing Wiley Blackwell (John Wiley Sons) 2014 ADVANCED ENERGY MATERIALS Vol.4 No.9

Evenly transferred single-layered graphene membrane assisted by strong substrate adhesion

Park, Seongjae,Kim, Hoijoon,Seol, Daehee,Park, Taejin,Leem, Mirine,Ha, Hyunwoo,An, Hyesung,You Kim, Hyun,Jeong, Seong-Jun,Park, Seongjun,Kim, Hyoungsub,Kim, Yunseok IOP 2017 Nanotechnology Vol.28 No.14

<P>We explored the transfer of a single-layered graphene membrane assisted by substrate adhesion. A relatively larger adhesion force was measured on the SiO<SUB>2</SUB> substrate compared with its van der Waals contribution, which is expected to result from the additional contribution of the chemical bonding force. Density functional theory calculations verified that the strong adhesion force was indeed accompanied by chemical bonding. The transfer of single-layered graphene and subsequent deposition of the dielectric layer were best performed on the SiO<SUB>2</SUB> substrate exhibiting a larger adhesion force. This study suggests the selection and/or modification of the underlying substrate for proper transfer of graphene as well as other 2D materials similar to graphene.</P>

Direct Observation of Wet Biological Samples by Graphene Liquid Cell Transmission Electron Microscopy

Park, Jungwon,Park, Hyesung,Ercius, Peter,Pegoraro, Adrian F.,Xu, Chen,Kim, Jin Woong,Han, Sang Hoon,Weitz, David A. American Chemical Society 2015 Nano letters Vol.15 No.7

<P>Recent development of liquid phase transmission electron microscopy (TEM) enables the study of specimens in wet ambient conditions within a liquid cell; however, direct structural observation of biological samples in their native solution using TEM is challenging since low-mass biomaterials embedded in a thick liquid layer of the host cell demonstrate low contrast. Furthermore, the integrity of delicate wet samples is easily compromised during typical sample preparation and TEM imaging. To overcome these limitations, we introduce a graphene liquid cell (GLC) using multilayer graphene sheets to reliably encapsulate and preserve biological samples in a liquid for TEM observation. We achieve nanometer scale spatial resolution with high contrast using low-dose TEM at room temperature, and we use the GLC to directly observe the structure of influenza viruses in their native buffer solution at room temperature. The GLC is further extended to investigate whole cells in wet conditions using TEM. We also demonstrate the potential of the GLC for correlative studies by TEM and fluorescence light microscopy imaging.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2015/nalefd.2015.15.issue-7/acs.nanolett.5b01636/production/images/medium/nl-2015-01636y_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl5b01636'>ACS Electronic Supporting Info</A></P>

High-Performance Flexible Organic Solar Cells exceeding 12% Enabled by High-Purity Transfer-Free Graphene Electrode produced via Direct Polyimide Integration

Hyesung Park(박혜성) 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.2

The use of an n-type macromolecular additive as a simple yet effective tool for improving and stabilizing the performance of organic solar cells

Park, Kwang Hyun,An, Yujin,Jung, Seungon,Park, Hyesung,Yang, Changduk The Royal Society of Chemistry 2016 ENERGY AND ENVIRONMENTAL SCIENCE Vol.9 No.11

<P>The discovery of an easy and powerful way to further improve and stabilize the performance of organic solar cells (OSCs) from the current levels would advance their commercialization. In this work, an unprecedented power conversion efficiency (PCE) of 11.6% with improved stability is demonstrated by using a high-quality n-type macromolecular additive P(NDI2OD-T2)<I>via</I>a simple route without additional processing steps, where the high-quality P(NDI2OD-T2) is isolated by a THF-soaking treatment. We attribute the improved performance to advantageous changes in the morphology of the photoactive materials induced by the macromolecular additive. In addition, using the ITO-free architecture on a flexible PET substrate, we obtain an impressive PCE of 5.66% in macromolecular additive-processed devices. Due to its great applicability and easy accessibility, the use of the macromolecular additive introduced in this study has great potential for broad applications with other OSC systems, which will accelerate the commercial viability of photovoltaic technology.</P>

Locking-In Optimal Nanoscale Structure Induced by Naphthalenediimide-Based Polymeric Additive Enables Efficient and Stable Inverted Polymer Solar Cells

Park, Kwang Hyun,An, Yujin,Jung, Seungon,Park, Hyesung,Yang, Changduk American Chemical Society 2017 ACS NANO Vol.11 No.7

<P>Operational stability and high performance are the most critical issues that must be addressed in order to propel and advance the current polymer solar cell (PSC) technology to the next level, such as manufacturing and mass production. Herein, we report a high power conversion efficiency (PCE) of 11.2%, together with an excellent device stability in PTB7-Th:PC71BM-based PSCs in the inverted structure by introducing the n-type P(NDI2OD-T2) macromolecular additive (>75% PCE retention at high temperature up to 120 degrees C, >97% PCE retention after 6 months in inert conditions, >93% PCE retention after 2 months in air with encapsulation, and >80% PCE retention after 140 h in air without encapsulation). The PCE is the highest value ever reported in the single-junction systems based on the PTB7 family and is also comparable to the previously reported highest PCE of inverted PSCs. These promising results are attributed to the efficient optimization and stabilization of the blend film morphology in the photoactive layer, achieved using the P(NDI2OD-T2) additive. From the perspective of manufacturing, our studies demonstrate a promising pathway for fabricating low-cost PSCs with high efficiency as well as long-term stability.</P>

ICM 기반 영재 언어통합프로그램이 고등학생의 영어 쓰기능력과 창의성에 미치는 영향

박혜성(Hyesung Park),이경화(Kyunghwa Lee) 한국영재교육학회 2016 영재와 영재교육 Vol.15 No.1

본 연구는 VanTassel-Baska(1998)에 의해 개발된 ICM 기반 영재 언어통합프로그램인 「Journeys and Destinations」이 고등학생의 영어 쓰기능력과 창의성 향상에 효과적 인지를 확인하는데 목적을 두었다. 이에 따라 외국어로 영어를 학습하는 고등학생에 게 적합하게 프로그램을 재구성하여 경기도 S시에 소재한 고등학교 1, 2학년 학생 중 영어성적 상위 30%에 해당하는 학생 48명을 연구대상으로 하여 실험연구를 하였다. 실험기간은 2015년 3월 12일에서 4월 9일까지였으며, 사전, 사후 검사로 영어 쓰기능력검사와 창의성 검사를 실시하였으며, 실험집단에는 영재 언어통합프로그램을 10차 시에 걸쳐 적용하였고, 통제집단에는 영어 정규수업 10차시를 적용하였다. 연구결과 에 따르면 실험집단과 통제집단에 있어서 통계적으로 유의한 차이가 나타나 ICM 기 반 영재 언어통합프로그램이 고등학생의 영어 쓰기능력과 창의성을 향상시키는데 효과적이었음이 확인되었다. The purpose of this study is to identify the effects of the English language arts program based on ICM, 「Journeys and Destinations」(VanTassel-Baska, 1998) on English writing competence and Creativity of high school students. For this study, this program was reconstructed for Korean high school students studying English as a foreign language. First and second graders of a high school in Suwon were selected as participants using their English scores; two groups of twenty-four students were randomly assigned as an experimental group and control group respectively. In this study, the English language arts program is proven to be effective in improving English writing competence among high school students. Second, this program is identified to be effective in fostering creative and language creativities. However, there is little difference between two groups in the creative inclination. These results suggest that the English language arts program can be used to enhance the English writing competence and the creative capability of high school students.

판촉 프레이밍이 보너스팩과 가격할인의 선호에 미치는 영향: 단위가격 착각의 효과

박혜성 ( Hyesung Park ),석관호 ( Kwanho Suk ) 한국소비자학회 2016 소비자학연구 Vol.27 No.6

본 논문은 판매촉진 정보의 제시방법(framing)이 소비자의 보너스팩과 가격할인에 대한 선호에 미치는 영향을 연구하였다. 기존의 판매촉진 연구들은 소비자들이 보너스팩보다 가격할인을 더 선호하는 경향이 있는 것을 보여주었다. 본 연구는 소비자의 두 유형의 판촉에 대한 상대적인 선호는 판매촉진 메시지 프레이밍과 할인의 크기에 따라 달라진다는 것을 제시하였다. 구체적으로, 판매촉진 메시지가 절대적 프레임으로 제시될 경우(예, xx원 할인, xx개 추가 증정)에는 소비자는 가격할인을 보너스팩보다 더 선호하나, 메시지가 상대적 프레임으로 제시될 경우(예, xx% 할인, xx% 추가 증정)에는 보너스팩에 대한 상대적 선호가 더 증가한다는 가설을 제시하였다. 또한 이러한 프레이밍 효과는 할인의 크기가 클수록 더 현저하게 나타날 것으로 기대했다. 연구 가설을 소비자의 구매의도(실험 1)와 선택(실험 2)을 종속변수로 한 두 실증연구를 통해 검증하였다. 실험 1은 인터넷 영화관 포인트를 구매하는 상황을 설정하여, 동일한 단위가격(unit price)을 가지는 가격할인과 보너스팩에 대한 평가가 메시지 프레이밍 방법에 따라 어떻게 달라지는 가를 검증하였다. 절대적 프레임으로 판매촉진 메시지가 제시되었을 경우에는 소비자들은 가격할인을 더 선호하였으나, 상대적 프레임 하에서는 보너스팩에 대한 선호가 증가하였다. 이와 같은 메시지 프레이밍의 효과는 할인폭이 큰 경우에만 유의한 것으로 나타났다. 실험 2에서는 실험 1의 외적타당성의 한계를 보완하고자 가격할인을 제공하는 대안과 보너스팩을 제공하는 대안에 대한 소비자의 선택을 조사하였다. 실험 2의 결과 또한 판매촉진에 대한 선택확률도 메시지 프레이임과 할인 크기에 따라 달라진다는 것을 보여주었다. This research examines the influence of the framing of promotional messages on the relative preference for price cut and bonus pack promotions that provide the same discounted unit price. The extant literature shows that consumers tend to prefer price cuts (that offer monetary savings) to bonus packs (that offer extra amount of the product). Although price cut is one of the most frequently used sales promotion tools and has strong impact on sales increase, it also has some limitations such as lowering perceived quality and reference price, resulting in decreases in potential future demand of the promoted product. Bonus pack promotion can be an alternative promotional tool with reduced negative long-term effects. Then, how can we increase consumers` preference for bonus pack promotion? This research extends the findings of prior studies and suggests that the relative preference for price cuts and bonus pack is moderated by whether the promotional message is absolutely framed (presenting the absolute amount of monetary savings or free extra-products) or relatively framed (presenting the percentage of monetary savings or free extra-products). Specifically, this research proposes and tests the following key hypotheses: (1) consumers prefer discount to bonus pack under the absolute frame, (2) consumers` preference for bonus pack increases under the relative frame, and (3) the framing effect is stronger when the discount is deeper than shallower. In case of the absolute frame, because consumers can easily recognize exact saving they can obtain from each type of sales promotion, they will evaluate it according to the amount of monetary saving (price cut) or the free extra amount of the products (bonus pack). Thus, their evaluation of sales promotions is more strongly affected by the discounted unit price. When the two types of the sales promotions offer the same unit price, consumers are likely to prefer discount to bonus pack, because of the benefits of price cuts such as lower transaction cost and inventory cost. In case of the relative frame, because consumers have difficulty in calculating the degree of discount they can get, they are more likely to evaluate it based on the value of the framed rates (discount rate, bonus pack rate). Given the same sale unit price, bonus pack rate is higher than that of price cut. For example, the sales promotion that offer 20% price discount is equivalent the bonus pack that offer 25% extra products in terms of the unit price. Because it is more difficult to calculate the unit price when the message is presented in the relative frame, consumers tend to rely more on the system 1 rather than system 2, resulting in a simple comparison of the presented price discount rate and bonus pack rate. Thus, relatively presented promotional messages should increase consumers` relative preference for bonus pack. Our proposed predictions are tested in two empirical studies. Experiment 1 set the situation to purchase points of Internet cinema. Participants rated their relative preference (in terms of purchase intention) for the two types of sales promotion that varied in terms of framing of sales promotion messages (absolute vs. relative) and the depth of discount (shallow vs. deep). The results showed that when promotion messages are absolutely framed, price cut promotion was preferred to bonus pack promotion. However, when messages are relatively framed, price cut promotion and bonus pack promotion were equally preferred. We also found that the moderating effect of message framing was more prominent when the discount rate was higher. These key findings are replicated in study 2 that examined the effects of message framing on consumer choice between two fitness centers, one offering price cut promotion and the other offering bonus pack promotion. Under the absolute frame, consumers were more likely to choose the fitness center that offered price cut promotion than that offered bonus pack promotion. When promotional messages are relatively framed, choice between price cut and bonus pack promotions did not differ. Through the both experiments, it showed that preference for the two types of sales promotion having the same unit price may vary according to the framing of sales promotion messages and the degree of discount. Theoretically this study has the significance to clarify the role of the unit price framed by sales promotion activities which the existing literature on the sales promotion has overlooked. And it also has the meaning to present that evaluation on different types of sales promotion having the same unit price may vary according to the message framing. And practically, it showed that preference for the certain sales promotion may be influenced by the method how marketers communicate sales promotion messages.

스마트도시 구축에 필요한 공공공간 디자인 요소 분석 연구

박혜성 ( Hyesung Park ),김주연 ( Jooyun Kim ) 한국공간디자인학회 2018 한국공간디자인학회논문집 Vol.13 No.3

(연구배경 및 목적) 세계는 도시화로 인하여 자원 및 인프라 부족, 교통혼잡, 에너지 부족 등 각종 도시문제가 심화되고 있다. 이에 따라 도시 문제의 해결을 위한 방법으로 스마트도시가 빠르게 확산되고 있다. 스마트도시는 정보통신 및 기술의 발전 4차 산업혁명 도래에 따른 시대적 화두와 맞물려 도시혁신의 새로운 모델로 증가하는 도시개발 수요를 바탕으로 각국에서 경쟁적으로 추진되고 있다. 정부에서도 ICT 기술을 활용, 도시문제를 해결하고 교통, 에너지, 환경 등 파급효과가 큰 미래 성장동력으로 스마트도시 정책을 추진하고 있다. 따라서 본 연구는 스마트도시 개발 시 공공공간에 필요한 디자인 요소를 파악하여 종합도시 계획 개념에 공공공간의 디자인 요소 적용이 초기에 적용될 수 있도록 하는데 의의가 있다. (연구방법) 본 연구에서는 스마트도시의 개념을 제시하고, 선행연구를 통해 도시디자인 및 공공공간, 공공디자인의 특성과 개념에 대해 이론적으로 고찰한다. 문헌조사를 통해 공공공간에 필요한 디자인 요소를 추출하였다. 선행연구를 통한 28개의 디자인 요소를 범주화하기 위하여 다차원 척도법(Multi dimensional Scaling , MDS)을 선정, 28개의 디자인요소의 유사성에 대하여 전문가 설문을 진행하였다. 설문조사 후 수집된 데이터를 SPSS 20.0 통계 패키지 프로그램에 코딩하여 다차원척도분석(MDS)을 실시하였다. (결과) MDS 분석 결과 각 좌표에 따라 분류된 그래프를 살펴보면, 5개의 그룹으로 유사성이 군집되는 것을 확인하였다. 5개로 범주화된 스마트도시의 공공공간 디자인요소는 안락성, 심미성, 역사성, 정책성, 경제성으로 정의하였다. 디자인은 사회전반에서 점점 중요시 되고 있으며 스마트도시 구축시 도시설계 단계에서부터 디자인 요소가 접근되어야한다. 또한 스마트 기반시설(스마트 에너지, 도로, 자원 재순환 등) 구축 시 위에서 분석된 디자인 요인을 바탕으로 스마트도시 구축 시 공공공간의 설계에 반영, 도시기능을 효율화하고 도시 문제를 해결하는데 활용되어야 할 것이다. (결론) 스마트도시는 기술을 기반으로 하고 있지만 도시공간을 이용하는 시민들이 접하게 되는 공간으로서 디자인 적용이 필수적으로 필요하다. 신정부는 스마트코리아를 추진하기 위하여 스마트도시 구축에 전력을 기울이고 있다. 이에 에너지, 교통, ICT등의 인프라 구축 또는 법·제도적 측면에서 디자인요소가 고려되어야 할 것이다. 기획, 설계, 운영, 관리의 통합적 도시개발 과정에서 디자인을 필요조건으로 인식하고. 본 연구를 바탕으로 향후 스마트도시 구축 단계에서 공공공간 영역이 공간·기술·주체별 맞춤형 전략 방안을 디자인적 접근을 통하여 모색 하고자한다. (Background and Purpose) As a result of urbanization, the world is becoming increasingly troubled by urban issues, such as lack of resources and infrastructure, congestion, and energy shortages. Accordingly, smart cities are increasingly being seen as a way to solve urban problems. Smart cities are competitively driven by the demand for urban development, which is a new model for urban innovation combined with the trend of the fourth industrial revolution. The government is also promoting smart city policies as future growth engines that will utilize ICT technology, solve city problems, and have a ripple effect on transportation, energy, and the environment. Accordingly, this study is significant in identifying design elements necessary for public spaces in smart city development so that the application of said design elements in public spaces can be initially applied to the general urban planning concept. (Method) In this study, concepts from smart cities are presented, and prior studies are used to explore the characteristics and concepts of urban design, public spaces and public design in a theoretical manner. From the literature review, the design elements required for public spaces were identified. To categorize 28 design elements from a prior study, the Multidimensional Scaling (MDS) method was selected, and its similarity to 28 design elements was explored. Data collected after the survey was coded into a SPSS 20.0 Statistical Package Program to carry out a MDS analysis. (Results) Based on the MDS analysis results, the graph grouped according to the respective coordinates was examined, revealing that the similarity could be organized into five groups. The five public space design elements of smart cities are comfort, aesthetics, historicity, restativeness, and economy. Design is becoming increasingly important across society, and design elements should be approached from the urban design phase in smart city deployments. In addition, smart infrastructure (smart energy, roads, resource recirculation, etc.) should be implemented to efficiently reflect on the design of the public spaces and to solve urban problems when constructing smart cities based on the design factors analyzed above. (Conclusions) Smart cities are based on technology, but design applications are essential as the spaces where citizens using urban spaces come into contact. The new government is making a concerted effort to build smart cities for a smart Korea. Accordingly, design elements should be considered in terms of infrastructure construction, including energy, transport and ICT, as well as legal and institutional aspects. Design is recognized as a necessary condition in the integrated urban development process of planning, design, operation, and management. Based on this research, we intend to seek a customized strategic plan for each spatiality, technology, and principals across all phases of smart city development.