A Study on the Role of Performance Measurement System in the Relation between Entrepreneurship and Organizational Performances

Changyeon Cho(조창연),Woongsoo Jeon(전웅수),Sungjin Son(손성진) 한국국제회계학회 2020 국제회계연구 Vol.0 No.94

[연구목적] 본 연구는 기업가정신과 조직성과의 관계에서 성과측정시스템(PMS)의 매개 효과를 규명한다. 구체적으로, 본 연구는 PMS의 진단적 이용과 상호작용적 이용, PMS 특성(질적 특성, 공정성)을 주요 관심변수로 선정하였다. [연구방법] 연구목적을 달성하기 위한 가설은 세 개인데, 가설 1은 기업가정신과 조직성과의 관계, 가설 2는 그 관계에서 PMS 이용방식의 역할, 가설 3은 그 관계에서 PMS 이용방식과 PMS 특성의 역할을 탐색하는 것이다. [연구결과] 본 연구의 결과는 첫째, 기업가정신은 조직성과에 정(+)의 영향을 미치지 않았다. 둘째, 기업가정신과 조직성과의 관계에서 PMS 이용방식, PMS 특성은 매개역할을 하였다. 셋째, 기업가정신과 조직성과의 관계에서 PMS 이용방식과 PMS 특성의 순차적인 다중매개 효과도 존재하였다. [연구의 시사점] 본 연구는 경영자가 기업가정신을 발휘하여 기업가치 극대화라는 목표를 달성하려면 PMS 진단, 상호작용적 이용방식과 더불어 PMS 질적 특성, 공정성과 같은 특성을 관리하려는 노력이 병행될 필요가 있다는 점을 시사하고 있다. [Purpose] The aim of this study is to examine a role of performance measurement system (PMS) in relation between entrepreneurship and organizational performances. More specifically, the study focuses on diagnostic and interactive use of one important aspect of PMS, and qualitative and justice characteristics of PMS. [Methodology] Three research questions are investigated: (ⅰ) to what extent do entrepreneurship contribute to organizational performances? (ⅱ) to what extent do the diagnostic and the interactive use of PMS, (ⅲ) to what extent do the qualitative characteristics and the justice of PMS specifically contribute to the relation between entrepreneurship and organizational performances. [Findings] The results of the study are as follows: Firstly, no positive direct effect on entrepreneurship on improvement of organizational performances was found. Secondly, the PMS use and the PMS characteristics played a mediating role in the relation between entrepreneurship and organizational performances. Thirdly, we found that multiple mediating effects of the PMS use and the PMS characteristics in the relation between entrepreneurship and organizational performances. [Implications] This study suggests that efforts to manage characteristics such as PMS qualitative characteristics and justice along with PMS diagnostic and interactive use need to be carried out in order for entrepreneur to achieve the goal of maximizing firm value.

옥수수의 Phosphoenolpyruvate Carboxylase와 Pyruvate Orthophosphate Dikinase가 발현되는 형질전환벼의 광합성특성에 관하여

Cho Dongha,Yoon Byeongsung,Yu Changyeon,Ko Jonghan,Ku Maurice 한국작물학회 2000 한국작물학회 학술발표대회 논문집 Vol.2000 No.1

Development and application of urban flood alert criteria considering damage records and runoff characteristics

Cho, Jeawoong,Kang, Hoseon,Bae, Changyeon 한국수자원학회 2018 한국수자원학회논문집 Vol.51 No.1

최근 집중호우로 서울 강남구(’12), 부산(’13), 울산(’16), 인천, 부산(’17) 등 대도시 지역의 침수 피해가 증가하고 있다. 도시침수는 하천유역의 홍수 피해와는 달리 매우 짧은 시간에 피해가 발생하며, 시설물의 파괴보다는 주택, 차량, 상가 침수로 인한 재산 피해가 높은 비율을 차지하고 있다. 현재 우리나라의 호우에 대한 예 ․ 경보는 기상청에서 발표하는 호우 주의보 및 경보에 의존하고 있지만, 기상청의 호우 주의보 및 경보는 전국공통 지표를 사용함으로써 지역적 특성을 반영하지 못하고 있는 실정이다. 따라서 본 연구에서는 서울과 울산지역을 대상으로 지역별로 피해이력 기반의 한계강우량을 추정하였으며, 피해이력이 없어 한계강우량 추정이 불가능한 지역에 대해서는 유역특성이 반영된 Neuro-Fuzzy 모형을 통해 한계강우량을 예측하였다. 추정된 한계강우량을 통해 도시침수 위험기준을 설정하고 실제 침수사상에 적용한 결과 추정된 한계강우량은 실제 한계강우량과 1.8~20.4%의 오차를 보이고 있으며, 최소 28분에서 최대 70분의 대피시간을 확보 할 수 있는 것으로 나타났다. 따라서 도시침수 예 ․ 경보를 위한 위험기준으로 활용가능 할 것으로 판단된다. Recently, localized heavy rainfall has led to increasing flood damage in urban areas such as Gangnam, Seoul (’12), Busan (’13), Ulsan (’16) Incheon and Busan (’17) etc. Urban flooding occurs relatively rapidly compared to flood damage in river basin, and property damage including damage to houses, cars and shopping centers is more serious than facility damage to structures such as levees and small bridges. In Korea, heavy rain warnings are currently announced using the criteria set by KMA (Korea Meteorological Administration). However, these criteria do not reflect regional characteristics and are not suitable to urban flood. So in this study, estimated the flooding limit rainfall amount based on the damage records for Seoul and Ulsan. And for regions that can not estimate the flooding limit rainfall since there is no damage records, we estimated the flooding limit rainfall using a Neuro-Fuzzy model with runoff characteristics. Based on the estimated flooding limit rainfall, the urban flood warning criteria was set. and applied to the actual flood event. As a result of comparing the estimated flooding limit rainfall with the actual flooding limit rainfall, the error of 1.8~20.4% occurred. And evacuation time was analyzed from a minimum of 28 minutes to a maximum of 70 minutes. Therefore, it can be used as a warning criteria in the urban flood.

Impact of highly crystalline, isoindigo-based small-molecular additives for enhancing the performance of all-polymer solar cells

Cho, Han-Hee,Han, Gibok,Younts, Robert,Lee, Wonho,Gautam, Bhoj R.,Lee, Seungjin,Lee, Changyeon,Kim, Taesu,Kim, Felix Sunjoo,Gundogdu, Kenan,Kim, Bumjoon J. The Royal Society of Chemistry 2017 Journal of materials chemistry. A, Materials for e Vol.5 No.40

<▼1><P>We have developed a simple yet versatile approach for enhancing the performance of all-polymer solar cells (all-PSCs) using a highly crystalline small-molecular additive, 6,6′-dithiopheneisoindigo (DTI).</P></▼1><▼2><P>We have developed a simple yet versatile approach for enhancing the performance of all-polymer solar cells (all-PSCs) using a highly crystalline small-molecular additive, 6,6′-dithiopheneisoindigo (DTI). The DTI additive in a blend of PTB7-Th donor and P(NDI2HD-T) acceptor enhances the power conversion efficiency of all-PSCs from 5.9 to 6.8%. Based on the analyses of the electrical, optical, and structural properties of all-PSCs, it is suggested that DTI additives promote tighter π–π packing and larger sizes of crystalline domains. Such morphological changes of the PTB7-Th:P(NDI2HD-T) blend films upon the addition of DTI enhance the exciton lifetime and diffusion length, which are proved by static and femtosecond-transient absorption spectroscopies and time-resolved photoluminescence. As a result of improved exciton dissociation probability and charge transport, the short-circuit current density of all-PSCs is greatly increased. Importantly, we also show that the DTI additive can be applied to other all-PSC systems with different polymer donors and naphthalene diimide (NDI)-based polymer acceptors, where the efficiencies of all-PSCs are enhanced by 10–20%.</P></▼2>

Improved Internal Quantum Efficiency and Light-Extraction Efficiency of Organic Light-Emitting Diodes via Synergistic Doping with Au and Ag Nanoparticles

Cho, Changsoon,Kang, Hyunbum,Baek, Se-Woong,Kim, Taesu,Lee, Changyeon,Kim, Bumjoon J.,Lee, Jung-Yong American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.41

<P>This paper reports the distinct roles- of Au and Ag nanoparticles; (NPs) in organic light-Orating-diodes (OLEDS) depending on their sizes. Au and Ag-NPs that.are 40 arid 50 nm in size, respectively, are the most effective for enhancing the performance of green: OLEDs. The external quantum efficiencies (EQEs): of green OLEDs doped with An and Ag N.Pg, (40 and 50 rim, respectiVely) are improved by 29.5% and 36.1%, respectively, while the power. efficiencies (PE8) are enhanced by 47.9% and 37.5%, respectively. Furthermore, combining the Au and Ag NPs produces greater enhancements. The EQE and PE of the coci-oped OLEDs are improved by 63.9% and 68.8% respectively,-.through the synergistic behavior of the different NPs. Finite difference time-domain simulations confirm that the localized surfaee:plasmon resonance of the Au NPs near 580 nth improves the radiative recombination rate (k(rad)) of green-light emitters locally (<50 pm), while the Ag NPs cause relatively long, range and broadband enhancements in k(rad). The-Simulations of 'various domain sizes. Verify that the light-extraction efficiency (LEE),can, be enhanced by More than 4.2% by applying Ag NPS.. Thus, size-controlled Au and Ag NPs can synergistically enhance LEDS by improving both the internal quantum efficiency and LEE.</P>

Esports에서의 Highlight 구간 예측

김창연(Changyeon Kim),송현호(Hyeonho Song),조윤재(Yoonjae Cho),차미영(Meeyoung Cha) 한국정보과학회 2019 한국정보과학회 학술발표논문집 Vol.2019 No.12

도시침수 상황관리를 위한 위험기준 및 모니터링 시스템 개발

조재웅(Cho, Jaewoong),강호선(Kang, Hoseon),배창연(Bae, Changyeon) 대한토목학회 2018 대한토목학회 학술대회 Vol.2018 No.10

Importance of 2D Conjugated Side Chains of Benzodithiophene-Based Polymers in Controlling Polymer Packing, Interfacial Ordering, and Composition Variations of All-Polymer Solar Cells

Lee, Changyeon,Giridhar, Thota,Choi, Joonhyeong,Kim, Seonha,Kim, Youngwoong,Kim, Taesu,Lee, Wonho,Cho, Han-Hee,Wang, Cheng,Ade, Harald,Kim, Bumjoon J. American Chemical Society 2017 Chemistry of materials Vol.29 No.21

<P>We delineate the important role of 2D conjugated alkylthiophene side chains of polymers in manipulating the molecular orientation and ordering at the polymer donor/polymer acceptor (<I>P</I><SUB>D</SUB>/<I>P</I><SUB>A</SUB>) interface as well as the composition variations in the blend active layer of all-polymer solar cells (all-PSCs). To systematically investigate the impact of 2D conjugated side chains on the performance of all-PSCs, we synthesized a series of poly(benzo[1,2-<I>b</I>:4,5-<I>b</I>̀]-dithiophene-thieno[3,4-<I>c</I>]pyrrole-4,6-dione) (PBDTTPD) polymer donors with different contents of alkoxy and alkylthiophene side chains, from 0 to 100% (PBDT-TPD (<B>P1</B>, 100% alkoxy side chain), PBDTT<SUB>0.29</SUB>-TPD (<B>P2</B>), PBDTT<SUB>0.59</SUB>-TPD (<B>P3</B>), PBDTT<SUB>0.76</SUB>-TPD (<B>P4</B>), and PBDTT-TPD (<B>P5</B>, 100% alkylthiophene side chain). The <B>P1</B>–<B>P5</B> polymer donors produced similar PCEs of ∼6% in fullerene-based PSCs. In contrast, for the all-PSC systems, the changes in the side chain composition of the polymers induced a strong increasing trend in the power conversion efficiencies (PCEs), from 2.82% (<B>P1</B>), to 3.16% (<B>P2</B>), to 4.41% (<B>P3</B>), to 5.32% (<B>P4</B>), and to 6.60% (<B>P5</B>). The significant increase in the PCEs of the all-PSCs was attributed mainly to improvements in the short-circuit current density (<I>J</I><SUB>SC</SUB>) and fill factor (FF). The 2D conjugated side chains promoted localized molecular orientation and ordering relative to the <I>P</I><SUB>D</SUB>/<I>P</I><SUB>A</SUB> interfaces and improved domain purity, which led to enhanced exciton dissociation and charge transport characteristics of the all-PSCs. Our observations highlight the advantage of incorporating 2D conjugated side chains into polymer donors for producing high-performance all-PSC systems.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2017/cmatex.2017.29.issue-21/acs.chemmater.7b03495/production/images/medium/cm-2017-03495e_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm7b03495'>ACS Electronic Supporting Info</A></P>

Estimate of the 225Ac Radioactive Isotope Distribution by Means of DOI Compton Imaging in Targeted Alpha Radiotherapy: A Monte Carlo Simulation

Yoon Changyeon,Jo Seongmin,Cho Yongho,Kim Nakjeom,Lee Taewoong 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.10

For successful targeted alpha radiotherapy (TAT), verifying the accurate position and distribution of a targeted radiotherapeutic agent in a patient or phantom is important. This paper, describes our investigation of depth-of-interaction (DOI) Compton imaging for the two γ-rays emitted during TAT with the 225Ac radioactive isotope. We optimized the design parameters of the DOI Compton camera, for example, the inter-detector distance, based on the figure of merit (FOM). The performance of DOI Compton imaging for TAT was improved because Doppler broadening and the energy uncertainty are inversely proportional to the radiation energy and the position uncertainty of the depth information is decreased. After the contrast phantom and the resolution phantom had been designed, two reconstruction algorithms, the filtered back-projection (FBP) algorithm and the maximum-likelihood expectation maximization (MLEM) algorithm, were applied to each reconstructed phantom image, and the qualities of the reconstructed images for the two γ-rays (218 keV and 440 keV) were compared. In the quantitative evaluation of the reconstructed images, the MLEM reconstruction algorithm performed better than the FBP algorithm. Based on Monte Carlo simulation studies, the DOI Compton images of the 225Ac radioactive isotope emitting two γ-rays demonstrated the capability of imaging a targeted radiotherapeutic agent in TAT.

Efficient Checkpointing of Live Virtual Machines

Egger, Bernhard,Cho, Younghyun,Jo, Changyeon,Park, Eunbyun,Lee, Jaejin IEEE 2016 IEEE Transactions on Computers Vol. No.

<P>The ability to save the state of a running virtual machine (VM) for later restoration is an important tool for home, server, and virtual desktop cloud (VDC) environments in order to achieve optimal and balanced hardware utilization. With guest memory sizes of four to eight gigabytes being the norm the time-and space-overhead of storing VM checkpoints still prevents an effective use of the technique. This work presents a method for fast and space-efficient checkpointing of VMs. Based on the observation that operating systems cache disk blocks in memory, the proposed technique transparently intercepts I/O operations and maintains an up-to-date mapping of memory pages and disk blocks containing identical data. At a checkpoint, those memory pages are excluded from the checkpoint image leading to a significant reduction of both the time and space required to take a checkpoint of a running VM. The broad applicability and good performance of the proposed method is demonstrated by an extensive set of experiments. We have implemented the technique for para-virtualized (PV), PVHVM, and fully-virtualized (HVM) guests in the Xen hypervisor. In comparison with an unmodified Xen hypervisor, experiments with Linux and Windows guests, on average, achieve a 86, 76, 53, and 47 percent reduction in the stored data and a 73, 62, 47, and 38 percent shorter time required to take a checkpoint for PV, PVHVM, HVM Linux, and HVM Windows guests, respectively.</P>