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

인덕터 동향

박지훈,Park, Ji-Hun 한국전기전자재료학회 2014 E²M-전기 전자와 첨단 소재 Vol.27 No.6

수위의 구속조건을 고려한 LCVA의 최적형상

박지훈,김기면,이성경,민경원,Park, Ji-Hun,Kim, Gi-Myun,Lee, Sung-Kyung,Min, Kyung-Won 한국전산구조공학회 2009 한국전산구조공학회논문집 Vol.22 No.5

This study addresses the optimal shape of a LCVA maximizing its vibration control effect through numerical parametric study. Various LCVAs having the same total mass and tuning frequency are designed with constraints on the dimensions and water level, and one obtaining the highest equivalent damping ratio of the controlled system is chosen as an optimal solution. As a result, it was found that the limit on the variation of the water level in the vertical liquid column plays an important role constraining the shape of the LCVA. As the LCVA width perpendicular to the plane of liquid motion increases, the equivalent damping ratio rises with slowdown so that determination of the proper width is important in design of the LCVA shape.

능동형 제진장치의 등가모델을 이용한 구조해석

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

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

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.

중국서 생존전략은 철저한 현지화

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

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.

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.

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.