봄무(Raphanus sativus)유식물에서 저온, ABA와 염분 스트레스가 Acid Phosphatase 활성에 미치는 영향

박지훈,조봉희,Park, Ji-Hun,Cho, Bong-Heuy 한국식물생명공학회 2002 식물생명공학회지 Vol.29 No.4

무 유식물에서 acid phosphatase의 활성은 산성인 pH 5.5에서 최대치를 보였다. 0.5 mM ABA처리로 acid phosphatase의 활성이 대조구보다는 오래 지속되였고, 0.5 mM NaCl 처리시 도 acid phosphatase 활성의 변화는 ABA 처리 때와 유사하였다. 그러나 저온처리를 하면, 대조구에 비해서 효소의 활성이 급속히 감소되었다가, 대조구의 acid phosphatase는 거의 같은 활성을 유지하는 동안 처리구의 acid phosphatae의 활성은 6 일까지 서서히 증가되었다. Acid phosphatase는 저온처리, ABA와 NaCl처리에 대항하여 식물이 스트레스에 대처하도록 생화학적인 반응에 관하는 것으로 보인다. Acid phosphatase in the radish young plant showed optimal activity at pH 5.5. The activity of acid phosphatase was maintained longer during the ABA (0.5 mM) treatment than those in control, whereas that was similar to the treatment of NaCl (0.5 mM). But during the cold (4$^{\circ}C$) treatment, the activity of acid phosphatase was decreased dramatically compared to the control, which was maintained almost on a constant level and increased gradually during 6 days. It showed that acid phosphatase was in relation to the change of biochemical reaction, which plants were coped with cold, NaCl and ABA stress.

능동형 제진장치의 등가모델을 이용한 구조해석

박지훈,윤수용,Park, Ji-Hun,Yun, Soo-Yong 한국전산구조공학회 2012 한국전산구조공학회논문집 Vol.25 No.4

본 논문에서는 구조물과 능동형 제진장치를 상용 구조해석 프로그램상에서 해석하는데 필요한 등가모델을 제시하였으며, 이를 통해 부재수준의 구조검토가 가능하도록 하기 위한 연구를 진행하였다. 능동형 제진장치를 일반적인 구조해석모델에 반영하기 위하여 가상의 스프링과 대쉬폿을 이용한 등가링크 모델과, 별도의 축소모델 해석결과를 바탕으로 산정된 제어력을 제진장치 설치위치에 하중으로 작용시키는 등가하중 모델을 제시하였다. 수직캔틸레버 모델과 주상복합 건물 모델을 대상으로 능동형 제어기 설계를 위해 모드에 기초한 축소모델을 구축하고, 이를 토대로 산정된 제어이득으로부터 등가모델을 도출하였다. 이들 모델에 대해 얻어진 가속도 및 변위의 RMS 응답과 최대 부재력을 토대로 등가해석모델의 유효성을 검증하였다. 결과적으로 능동형 제진장치의 상용 구조해석 프로그램을 통해 제어대상 구조물의 부재력 수준까지 상세한 구조검토가 가능함을 확인하였으며, 상대적으로 등가링크 모델이 더 우수한 정확도를 나타내었다. In this paper, equivalent models for active control devices are proposed so that building structures with such devices are analyzed using commercial structural analysis programs for the assessment of the structural members under active vibration control. Equivalent link models represent active control device with a virtual linear spring and dashpot, and equivalent force models are control force history acting at the installation point in structural models. Active controllers are designed based on the reduced-order models for a vertical cantilever model and a high-rise building model and corresponding equivalent models are determined from control gain matrices. Based on acceleration, displacement and member force responses, the effectiveness of the equivalent models is verified. As a result, proposed equivalent models, of which equivalent link model showed better performance, appear to enable detailed investigation of structural behavior to the extent of member force level.

KBC 2016에 따른 감쇠시스템 적용 구조물의 내진설계

박지훈,전성하,Park, Ji-Hun,Jeon, Seong-Ha 한국전산구조공학회 2017 전산구조공학 Vol.30 No.1

실크 피브로인 수화 겔의 형성에 미치는 티로시나아제 및 폴리페놀 화합물의 영향

박지훈,정임,박원호,Park, Ji-Hun,Jeong, Lim,Park, Won-Ho 한국섬유공학회 2009 한국섬유공학회지 Vol.46 No.2

The formation of silk fibroin (SF) hydrogel can be adjusted by changing physical conditions such as concentration of SF aqueous solution, temperature, pH and salts. In this study, tyrosinase (Tyr), which is an enzyme catalyzing the oxidation of phenols such as tyrosine, was used to decrease the gelation time of SF aqueous solution under a fixed conditions. Tyr oxidizes a broad range of phenols into very reactive o-quinones, and consequently quinones undergo non-enzymatic reactions with various nucleophiles. So it is expected that the gelation time of SF aqueous solution could be decreased by polyphenol compound such as caffeic acid and chlorogenic acid. The color of SF aqueous solutions containing Tyr was changed into deeper yellow with Tyr concentration, and also the gelation time of SF aqueous solution slightly decreased. However, the effect of Tyr concentration on gelation time of SF aqueous solution was not significant due to the locational hindrance of tyrosyl residues in SF. Absorbance at 550 nm also showed conformational transition (random coil to $\beta$-sheet conformation) of SF structure. When polyphenol compounds were added into SF/Tyr aqueous solution, the gelation time slightly decreased. However, the phase separation occurred when polyphenol compounds more than 5 mM were added. The results obtained in this study indicate that enzyme and additives have a potential to regulate the gelation behavior of SF aqueous solution, to some extent.

A Content-based Audio Retrieval System Supporting Efficient Expansion of Audio Database

박지훈,강현철,Park, Ji Hun,Kang, Hyunchul Digital Contents Society 2017 한국디지털콘텐츠학회논문지 Vol.18 No.5

For content-based audio retrieval which is one of main functions in audio service, the techniques for extracting fingerprints from the audio source, storing and indexing them in a database are widely used. However, if the fingerprints of new audio sources are continually inserted into the database, there is a problem that space efficiency as well as audio retrieval performance are gradually deteriorated. Therefore, there is a need for techniques to support efficient expansion of audio database without periodic reorganization of the database that would increase the system operation cost. In this paper, we design a content-based audio retrieval system that solves this problem by using MapReduce and NoSQL database in a cluster computing environment based on the Shazam's fingerprinting algorithm, and evaluate its performance through a detailed set of experiments using real world audio data. 음원 서비스의 주요 기능 중 하나인 내용 기반 검색을 위해 음원의 지문을 채취하여 데이타베이스에 저장하고 색인하여 검색에 활용하는 기법이 널리 사용되고 있다. 그런데 지속적으로 추가되는 신규 음원의 지문이 기존의 데이타베이스에 계속 삽입되면 공간 효율 및 음원 검색 성능의 저하가 점차 초래되는 문제점이 있다. 따라서 시스템 운용 비용의 증가를 가져오는 주기적인 데이터 베이스 재구성 없이 효율적인 음원 데이타베이스의 확장을 지원하는 기법이 요구된다. 본 논문에서는 샤잠의 지문 채취 알고리즘을 기반으로 클러스터 컴퓨팅 환경에서 맵리듀스 및 NoSQL 데이타베이스를 사용하여 이러한 문제를 해결하는 내용 기반 음원 검색 시스템의 설계를 제시하고 실제 음원 데이터를 이용한 다양한 실험을 통해 그 성능을 평가한다.

해외사례를 통해 살펴본 서울시 주차상한제 개선방향

박지훈,이태헌,이신해,Park, Ji-Hun,Lee, Tae-Heon,Lee, Sin-Hae 대한교통학회 2016 교통 기술과 정책 Vol.13 No.2

저온 증착된 불소도핑 주석 산화 박막의 광학적·전기적 특성

박지훈,전법주,Park, Ji Hun,Jeon, Bup Ju 한국재료학회 2013 한국재료학회지 Vol.23 No.9

The electrical and optical properties of fluorine-doped tin oxide films grown on polyethylene terephthalate film with a hardness of 3 using electron cyclotron resonance plasma with linear microwave of 2.45 GHz of high ionization energy were investigated. Fluorine-doped tin oxide films with a magnetic field of 875 Gauss and the highest resistance uniformity were obtained. In particular, the magnetic field could be controlled by varying the distribution in electron cyclotron deposition positions. The films were deposited at various gas flow rates of hydrogen and carrier gas of an organometallic source. The surface morphology, electrical resistivity, transmittance, and color in the visible range of the deposited film were examined using SEM, a four-point probe instrument, and a spectrophotometer. The electromagnetic field for electron cyclotron resonance condition was uniformly formed in at a position 16 cm from the center along the Z-axis. The plasma spatial distribution of magnetic current on the roll substrate surface in the film was considerably affected by the electron cyclotron systems. The relative resistance uniformity of electrical properties was obtained in film prepared with a magnetic field in the current range of 180~200A. SEM images showing the surface morphologies of a film deposited on PET with a width of 50 cm revealed that the grains were uniformly distributed with sizes in the range of 2~7 nm. In our experimental range, the electrical resistivity of film was able to observe from $1.0{\times}10^{-2}$ to $1.0{\times}10^{-1}{\Omega}cm$ where optical transmittance at 550 nm was 87~89 %. These properties were depended on the flow rate of the gas, hydrogen and carrier gas of the organometallic source, respectively.

인덕터 동향

박지훈,Park, Ji-Hun 한국전기전자재료학회 2014 전기전자재료 Vol.27 No.6

완전탄소성 감쇠기가 설치된 철근콘크리트 건물의 지진응답

박지훈,김훈희,Park, Ji-Hun,Kim, Hun-Hee 대한건축학회 2011 대한건축학회논문집 Vol.27 No.8

Empirical equation for estimating seismic response of the stiffness-degrading inelastic SDOF structures with fully elasto-plastic dampers are applied to 6- and 3-story reinforced concrete building structures with or without bearing walls. Fully elasto-plastic dampers are designed based on the nonlinear pushover analysis result for the bare frames. Nonlinear time history analysis is performed for the building models with dampers, and their ductility demands and spectral accelerations are transformed to those of SDOF structures, and compared with the response estimated using empirical equations for inelastic SDOF structures. Empirical equations estimates the ductility demands with reasonable accuracy, but the spectral accelerations have errors unacceptable for design purposes due to higher mode effects, which requires further improvement.

중국서 생존전략은 철저한 현지화

박지훈,Park, Ji-Hun 한국데이터베이스진흥원 2005 디지털콘텐츠 Vol.12 No.-