연료전지 기술개발의 현황과 전망

허필원 한국표면공학회 2009 한국표면공학회 학술발표회 초록집 Vol.2009 No.-

Current Hand Exoskeleton Technologies for Rehabilitation and Assistive Engineering

허필원,김정,구광민,이수진,이계한 한국정밀공학회 2012 International Journal of Precision Engineering and Vol.13 No.5

In this paper, we present a comprehensive review of hand exoskeleton technologies for rehabilitation and assistive engineering, from basic hand biomechanics to actuator technologies. Because of rapid advances in mechanical designs and control algorithms for electro-mechanical systems, exoskeleton devices have been developed significantly, but are still limited to use in larger body areas such as upper and lower limbs. However, because of their requirements for smaller size and rich tactile sensing capabilities, hand exoskeletons still face many challenges in many technical areas, including hand biomechanics, neurophysiology, rehabilitation, actuators and sensors, physical human-robot interactions and ergonomics. This paper reviews the state-of-the-art of active hand exoskeletons for applications in the areas of rehabilitation and assistive robotics. The main requirements of these hand exoskeleton devices are also identified and the mechanical designs of existing devices are classified. The challenges facing an active hand exoskeleton robot are also discussed.

한국 오피스시장의 보증금 비중 결정요인 분석

허필원,심교언 한국감정원 2017 부동산분석 Vol.3 No.1

The monthly rent contract with a security deposit has become a prominent form of lease agreement in the office rental market. This study aimed at understanding the mechanisms underlying security deposits and examining their characteristics and functions in the market; and ultimately perform an empirical analysis of the factors that determine the security deposit rate. Aa a result of the empirical analysis, it was found that the security deposit rate was high when: 1) the lessor was an individual, 2) the ratio of the lessor’s debt was high, 3) the building had a small number of lessees per unit area, or 4) the business types of lessees were very limited. On the other hand, it was found that the security deposit rate was kept low when the building prices were high, or when the buildings were large. However, in Seoul, medium-sized buildings also tended to have a high security deposit rate, possibly functioning as leverage. In the case of offices in Seoul, the lessors’ traits such as owner’s identity and loan ratio had significant effects on the security deposit rate, whereas in other suburban areas, these traits had no significant effect. 본 연구는 보증부월세가 주요한 임대계약 형태로 자리잡은 오피스 임대시장에서 보증금의 작동기제를 이해하고, 보증금의 특성과 역할에 대해 고찰한 후 보증금의 비중을 결정하는 요인을 실증분석 하는 것을 목적으로 한다. 가격 대비 보증금 비중 결정요인에 대한 실증분석 결과 임대인이 개인이고, 대출금 비율이 높을수록, 그리고 단위면적당 임차인수가 작고, 업종수가 적은 빌딩일수록 보증금 비중이 높은 것으로 나타났다. 또한 빌딩가격이 높고, 소형빌딩에 비해 대형빌딩일수록 보증금 비중을 낮게 유지하는 것으로 나타났다. 서울 오피스만을 대상으로 분석한 결과에서는 임대인특성인 소유주체와 대출금 비율이 보증금 비중 결정에 영향을 주는 반면, 지방은 임대인특성이 유의미한 결과가 나타나지 않았다. 그리고 빌딩의 가격수준이 높고, 상대적으로 대형빌딩 일수록 보증금 비중이 낮았다. 다만 서울의 중형빌딩은 오히려 보증금 비중이 높아 보증금이 주요한 레버리지 수단으로 활용되고 있는 것으로 짐작된다.

A Study of Comovement and Factors Causing Volatility in REIT Returns Before and After the Global Financial Crisis

허필원,김성희,심교언 한국부동산연구원 2013 부동산연구 Vol.23 No.3

The purpose of this study is to grasp an understanding of the market comovement in terms of REIT returns and to find the asymmetric effects of information that may cause volatility in REIT returns. In order to demonstrate the research findings, an empirical analysis was performed with the use of correlation analysis, VECM, AR(1)-TGARCH (1, 1), AR(1)- EGARCH (1, 1), and AR(1)-GARCH (1, 1). The results of the analysis are as follows. First, the correlation analysis showed that there was a significant positive correlation between REIT returns in the four countries, the U.S., Japan, Singapore, and Hong Kong, which showed that there was comovement mechanism at work between the countries subject to analysis. The correlation between the countries, however, was not that high. Next, with the use of VECM, it was seen that Japan and Singapore had significant impacts on REIT returns in the U.S. throughout the overall period. This verified that the comovement here is not a unilateral, but interactive relationship. The VECM analysis was conducted on the REIT performance in response to the Lehman’s bankruptcy and the result showed that the influence of each country on itself was diminished in terms of REIT returns after the Lehman shock. In AR(1)-TGARCH (1, 1) model, AR(1)-EGARCH (1, 1) model, and AR(1)-GARCH (1, 1) model, Singapore and the U.S. were more predictable in terms of REIT returns compared to Hong Kong and Japan in the overall period. An analysis of asymmetric information showed that in all countries with the exception of Hong Kong, the degree of impact that information has on price volatility is asymmetric and it may be said that information asymmetry in Asian countries is weaker than that of the U.S.

힘 기반 상지부 보조 장치의 보조 개시 신호로써의 근전도 신호 적용

허필원(P. Heo),김정(J. Kim),구광민(G. M. Gu),이효상(H. S. Lee),김상준(S. J. Kim) 한국정밀공학회 2014 한국정밀공학회 학술발표대회 논문집 Vol.2014 No.5월

다채널 디스플레이에서 X3D와 모션체어를 이용한 수중운동체 시뮬레이터

허필원(Pilwon Hur),양정삼(Jeongsam Yang),한순흥(Soonhung Han) (사)한국CDE학회 2008 한국CDE학회 논문집 Vol.13 No.1

서울시 오피스빌딩 임차인 업종별 특성 연구

허필원(Huh, Pil Won),조주현(Cho, Joo Hyun),심교언(Shim, Gyo Eon) 한국부동산학회 2013 不動産學報 Vol.54 No.-

1. CONTENTS (1) RESEARCH OBJECTIVES This study seeks to find the business characteristics by industry that rent medium to large office spaces in Seoul. (2) RESEARCH METHOD First, it seeks to find the different characteristics in lessee composition of medium to large office buildings in Seoul. Second, it aims to understand the possibile interrelationship of locations between the industries in which lessee businesses are and to compare them. Third, it seeks to present a new standard that may be used in determining which industries are specialized in certain areas by reviewing the office space rented in three major office building areas of Seoul and the number of businesses in it. (3) RESEARCH FINDINGS The analysis showed that the average number of industries that the lessees of medium to large office buildings were engaged in was 6.5. The major lessees engaged in industries like banking and insurance, manufacturing, and wholesale and retail industries were found to use 40-49% of total office spaces and the other industries the remaining spaces. 2. RESULTS The findings showed that in CBD transportation, banking & insurance, public administration, defense industry, social securities and several other service industries were found to be specialized both in terms of office space rented and the number of businesses; and in YBD manufacturing, lodging and restaurant, health, social welfare services; and in KBD manufacturing, wholesale & retail, science, technologies services.

부분 개방형 구조를 갖는 손가락 힘 보조 장치

허필원(P. Heo),김상준(S. J. Kim),김정(J. Kim) 한국정밀공학회 2013 한국정밀공학회 학술발표대회 논문집 Vol.2013 No.5월

부상된 수소난류확산화염에서 동축공기의 음향가진에 의한 NOx 저감

허필원(Pilwon Heo),오정석(Jeongseog Oh),윤영빈(Youngbin Yoon) 한국연소학회 2008 KOSCOSYMPOSIUM논문집 Vol.- No.-

The effect of acoustic excitation to the emission level of NOx was investigated. The purpose of this work was to study the effects of acoustic excitation on NOx emission reduction and mixing of fuel and air. A compression driver was attached to the coaxial air supply tube to impose excitation. Acoustic excitation experiments at various frequencies were performed to find out the effective excitation frequency. Then schlieren photographs were taken to visualize the flow near the lifted flame base. Experimental results shows that excitation with the frequencies similar to the resonance frequencies of combustor could reduce NOx emission significantly. This reduction was influenced by fluctuation of coaxial air jet velocity at nozzle exit. The vortices formed by the coaxial air jet velocity fluctuation helped mixing of hydrogen and coaxial air, lowering NOx 'emission.

GE 7FA+e DLN-2.6 가스터빈 연소기에서의 on-line 동압 측정 시스템

허필원(Pilwon Heo),오정석(Jeongseog Oh),윤영빈(Youngbin Yoon) 한국연소학회 2008 KOSCOSYMPOSIUM논문집 Vol.- No.-

Many of modem gas turbines use dry low NOx technology, which bums fuel in lean premixed condition, to reduce pollutant emission. However because of the susceptibility of combustion instability, it is very important to monitor the dynamic pressure of combustor. There are two types of pressure measuring probe commonly used: the long line probe and the cavity type probe. Knowing that it is more cost-effective to use long line probe, the on-line dynamic pressure monitoring system was composed in this research to build own measurement system. The frequency response of measuring probe was analyzed, and the simultaneous measurement with existing GE measuring toolkit was done to confirm the value in use.