Improvement of blood culture contamination rate, blood volume, and true positive rate after introducing a dedicated phlebotomy team

Bae, Moonsuk,In Kim, Hae,Park, Joung Ha,Ryu, Byung-Han,Chang, Jeonghyun,Sung, Heungsup,Jung, Jiwon,Kim, Min Jae,Kim, Sung-Han,Lee, Sang-Oh,Choi, Sang-Ho,Kim, Yang Soo,Woo, Jun Hee,Kim, Mi-Na,Chong, Yo Springer-Verlag 2019 European journal of clinical microbiology & infect Vol.38 No.2

A Note on the Determinacy Paradox : The Art of Policy Advice to Endogenous Government with Its Own Motivation

Jeonghyun Kim(김정현) 한국법경제학회 2007 법경제학연구 Vol.4 No.1

경제이론의 발전에 따라 정부부문이 모형 내에 내생화되면서 정부의 행동 및 정책결정에 대하여 보다 심도 있는 이해가 가능하게 된 반면“Determinacy Paradox”라는 문제에 직면하게 된다. 이는 정부의 행동양식이 스스로 동기를 갖는 합리적인 경제주체로서의 활동으로 모형 내에서 결정될 때, 전통적으로 경제학자 본연의 역할로 여겨져 왔던 정부에 대한 규범적인 정책조언활동이 과연 가능한지에 대한 문제제기이다. 본 논문은 determinacy paradox가 갖는 함의를 명확히 규명하고 정보의 비대칭성 및 정부의 목적함수에 주목하여 역설적인 결과의 해결가능성을 모색한다. 정책조언의 ‘존재가능성’에 초점을 맞추는 경우에는 불확실성하의 정보의 비대칭성이 determinacy paradox를 해결하는 데 핵심적인 요소가 된다. 규범적 정책조언의 ‘채택가능성’에 초점을 맞추는 경우에는 정부가 자체적으로 갖는 목적함수를 고려하는 것이 중요하게 된다. Basu(1997)가 보여 주는 회의적인 결과와는 달리, 일정한 제약조건에 직면한 정부가 마치 자신의 목적이 사회후생을 극대화하는 데 있는 것처럼 행동하는 경우 또는 정부와 경제학자가 비슷한 목적함수를 가지고 있는 경우에는 정부에 대한 정책조언이 의미 있는 활동이 될 수 있으며, 이에 따라 약한 형태의 determinacy paradox를 성공적으로 극복할 수 있다. As increasing numbers of economic models endogenize government, we get more fruitful understanding about its policy determination. With policies endogenously determined, how-ever, we confront the "determinacy paradox" that addresses the possible conflict between two traditional activities by economists: advising government "what should be done" vs. predicting "what government will do." In this note I clarify the implication of the determinacy paradox and explore how to resolve the paradoxical result, focusing on asymmetric information and the government"s objective function. When we focus on the "possibility of existence" of advice, asymmetric information under uncertainty plays a key role in resolving the determinacy paradox. When we concentrate on the "acceptability" of normative advice, considering government"s own objective becomes a crucial job. Unlike Basu(1997)"s skeptical result, when government behaves by some constraints as if its aim were maximizing social welfare, or when government and the economist share the similar objectives, giving advice to government can be a sensible activity, so that we can successfully overcome the weak form of the determinacy paradox.

Wet Area and Puddle Detection for Advanced Driver Assistance Systems (ADAS) Using a Stereo Camera

Kim, Jisu,Baek, Jeonghyun,Choi, Hyukdoo,Kim, Euntai Institute of Control, Robotics and Systems 2016 International Journal of Control, Automation, and Vol.14 No.1

Wet area or puddle detection is one of the key issues for safe driving and future Advanced Driver Assistance Systems (ADAS). A new methodology for the detection of wet areas and puddles using a stereo camera is presented in this paper. Because wet areas and puddles have different characteristics, the two areas are separately treated and different detection algorithms are proposed. For the detection of wet areas, color information is used for hypothesis generation (HG) and a support vector machine (SVM) is employed for hypothesis verification (HV). In HV, three features are proposed for classification; these are the polarization difference, graininess and gradient magnitude. For the detection of puddles, the depth map obtained by a stereo camera is used to exploit the fact that abrupt depth changes are detected around the puddles. In the experiment, it is shown that the proposed methods have a robust performance for the detection of wet areas or puddles.

Preparation and capacitance properties of graphene based composite electrodes containing various inorganic metal oxides

Jeonghyun Kim,Sang Chul Byun,Sungwook Chung,Seok Kim 한국탄소학회 2018 Carbon Letters Vol.25 No.-

Electrochemical properties and performance of composites performed by incorporating metal oxide or metal hydroxide on carbon materials based on graphene and carbon nanotube (CNT) were analyzed. From the surface analysis by field emission scanning electron microscopy and field emission transmission electron microscopy, it was confirmed that graphene, CNT and metal materials are well dispersed in the ternary composites. In addition, structural and elemental analyses of the composite were conducted. The electrochemical characteristics of the ternary composites were analyzed by cyclic voltammetry, galvanostatic charge-discharge tests, and electrochemical impedance spectroscopy in 6 M KOH, or 1 M Na2SO4 electrolyte solution. The highest specific capacitance was 1622 F g–1 obtained for NiCo-containing graphene with NiCo ratio of 2 to 1 (GNiCo 2:1) and the GNS/single-walled carbon nanotubes/Ni(OH)2 (20 wt%) composite had the maximum specific capacitance of 1149 F g–1. The specific capacitance and rate-capability of the CNT/MnO2/reduced graphene oxide (RGO) composites were improved as compared to the MnO2/RGO composites without CNTs. The MnO2/RGO composite containing 20 wt% CNT with reference to RGO exhibited the best specific capacitance of 208.9 F g–1 at a current density of 0.5 A g–1 and 77.2% capacitance retention at a current density of 10 A g–1.

Design Integrated Parametric Modeling Methodology for Han-ok

Kim, Jeonghyun,Jeon, Bong Hee Architectural Institute of Japan 2012 JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEE Vol.11 No.2

<P> Han-ok, the traditional Korean house, has the timber frame structure which is common in East Asia. Because the timber frame structure requires a vast amount of hand-cutting woodwork, prefabrication based on computer aided manufacturing (CAM) should be applied to reduce the construction cost of Han-ok. In order to implement them successfully, it is necessary to manage the building information in an organized system based on data handling technology, such as building information modeling (BIM) and parametric modeling. Three-dimensional, object-based parametric modeling technology not only enhances the construction process but also associates well with design study, especially when applying it to Han-ok. By applying the principle of Kan, the Korean traditional concept of a bay, this paper suggests a parametric modeling methodology that reduces modeling tasks and increases the efficiency of design study. </P>

Hydroxylated carbon nanotube enhanced sulfur cathodes for improved electrochemical performance of lithium-sulfur batteries.

Kim, Joo Hyun,Fu, Kun,Choi, Junghyun,Sun, Seho,Kim, Jeonghyun,Hu, Liangbing,Paik, Ungyu The Royal Society of Chemistry 2015 Chemical communications Vol.51 No.71

<P>Hydroxylated multi-walled carbon nanotubes were introduced into sulfur cathodes to utilize the hydrophilic attraction between the OH group and polysulfides as well as to increase the utilization of sulfur. This approach shows a promising strategy for diminishing the polysulfides shuttling behavior and improving the electrochemical performance of lithium-sulfur batteries.</P>

A Comparative Usability Assessment for Developing a Racing Handcycle

Jeonghyun Kim,Jongbae Kim,Seung Woo Hwangbo,Ji-hyuk Park,Joo Hyun Lee 대한인간공학회 2015 대한인간공학회 학술대회논문집 Vol.2015 No.10

Objective: The purpose of this study was to proceed comparative usability assessment with products to improve usability, and apply the deducted improvement points and recommendations from the results to develop a racing hancycle.. Background: Since racing handcycles for people with disability are all imported products, localization is positively necessary for improving athletic performances. Therefore, a racing hancycle considering the usability and body types of domestic players has been developed and a comparative usability assessment were proceeded with first prototype and two imported goods athletes currently use. Method: A comparative usability assessment was conducted with one domestically developed racing handcycle prototype and two mostly used imported handcycles. Total four handcycle club players participated in this comparative usability test and same protocols and scenarios were applied to the participants. The comparative usability test included effectiveness which measures the error count, Efficiency which measures duration time, and Satisfaction of the users. All of these factors were quantitatively evaluated. Results: Among three products, domestically developed handcycle prototype indicated second high scores in Effectiveness, Efficiency, and Satisfaction. Especially in Satisfaction domain, the score difference was less than 0.2. Conclusion: As a result of the comparative usability assessment among three products, domestically developed handcycle showed second high usability.

Synthesis of Fe₂O₃/KOH-Activated Reduced Graphene Oxide Electrodes and Their Electrochemical Analysis

Kim, Jeonghyun,Park, Soo-Jin,Kim, Seok American Scientific Publishers 2018 Journal of Nanoscience and Nanotechnology Vol.18 No.1

<P>We fabricated KOH-activated reduced graphene oxide (rGO)/Fe2O3 composites using a facile two-step synthesis by homogeneous precipitation and subsequent reduction of the GO. The total specific capacity of Fe2O3/KOH-activated rGO was higher than the sum of KOH-activated rGO and nanoparticle Fe2O3. It indicated a synergy effect of rGO, and Fe2O3 on the improvement of electrochemical performance. The structure and morphology of the composites were characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM). Electrochemical properties were characterized by cyclic voltammetry (CV) and charge-discharge (CD) in 6M KOH electrolyte.</P>

Synthesis of Li2MnSiO4-graphene composite and its electrochemical performances as a cathode material for lithium ion batteries.

Kim, Jeonghyun,Song, Taeseup,Park, Hyunjung,Yuh, Junhan,Paik, Ungyu American Scientific Publishers 2014 Journal of Nanoscience and Nanotechnology Vol.14 No.10

<P>The Li2MnSiO4 is a promising candidate as a cathode for lithium ion batteries due to its large theoretical capacity of 330 mA h g(-1) and high thermal stability. However, the problems related to low electronic conductivity and large irreversible capacity at the first cycle limits its practical use as a Li-ion cathode material. We have developed a carbon coated Li2MnSiO4-graphene composite electrode to overcome these problems. Our designed electrode exhibits high reversible capacity of 301 mA h g(-1), with a high initial coulombic efficiency, and a discharge capacity at current rate of 0.5 C, that is double value of carbon coated Li2MnSiO4-carbon black composite electrode. These significant improvements are attributed to fast electron transport along the graphene sheet.</P>

Interaction of Learning Motivation with Dashboard Intervention and Its Effect on Learning Achievement

( Jeonghyun Kim ),( Yeonjeong Park ),( Dami Huh ),( Il-hyun Jo ) 한국교육공학회 2017 Educational Technology International Vol.18 No.2

The learning analytics dashboard (LAD) is a supporting tool for teaching and learning in its personalized, automatic, and visual aspects. While several studies have focused on the effect of using dashboard on learning achievement, there is a research gap concerning the impacts of learners’ characteristics on it. Accordingly, this study attempted to verify the differences in learning achievement depending on learning motivation level (high vs. low) and dashboard intervention (use vs. non-use). The final participants were 231 university students enrolled in a basic statistics course. As a research design, a 2 x 2 factorial design was employed. The results showed that learning achievement varied with dashboard intervention and the interaction effect was significant between learning motivation and dashboard intervention. The results imply that the impact of LAD may vary depending on learner characteristics. Consequently, this study suggests that the dashboard interventions should be offered after careful consideration of individual students’ differences, particularly their learning motivation.