소비자 조사와 착의 실험을 통한 온도감응형 기능성 의류개발을 위한 기초연구

상정선 ( Jeong-seon Sang ),정경화 ( Kyunghwa Chung ),박주현 ( Juhyun Park ),오경화 ( Kyung Wha Oh ) 한국의류산업학회 2017 한국의류산업학회지 Vol.19 No.1

In this research, consumer awareness investigation and wearing test were carried out for obtaining useful data on the development of thermo-sensitive functional clothing material. A survey involved 216 people in Seoul and Kyeonggi- do, and 200 questionnaires data were analyzed by descriptive statistics and frequency using SPSS 17.0. Four healthy men in twenties were participated for wearing test. Subjects in normal loungewear were exposed to temperature change from the initial temperature 30oC down to 5oC for an hour in a climate chamber. The environmental temperature, surface temperature of garment and skin were measured. As a result, most of respondents have all season clothing products such as underwear, hosiery, and jogging suit for loungewear. Also, thermo regulator y functional clothes are frequently used as underwear and sweat shirt. The consumer awareness investigation on thermo regulatory functional clothing showed that the most important key buying factor is quick climate temperature response, easy maintenance, design and cost, in that order. Surface temperature of garment went down with the cooling down of environmental temperature. The lower environmental temperature, the greater temperature difference by body part showed. Skin temperature change by environmental temperature showed similar tendency of garment surface temperature. In comparison between garment surface and body skin, temperature difference became larger under the lower environmental temperature.

Fingertip Force and Muscle Activation Patterns at Varying grasp Objects

Suji Park(Suji Park),Juhyun Park(Juhyun Park),Seyeon Oh(Seyeon Oh),Chaeyeon Heo(Chaeyeon Heo),Sieun Ho(Sieun Ho),Seonhong Hwang(Seonhong Hwang) 호서대학교 기초과학연구소 2022 기초과학연구 논문집 Vol.30 No.1

In this study, we tried to collect and analyze the kinetic and neurological information such as finger-tip forces and EMG for several representative (the most commonly used) grasp movements to explore their force and muscle activation patterns based on the newly defined grasp taxonomy. Ten able-bodied (five males, five females) volunteered to participate and they performed five different grasp tasks: holding a bottle (Bottle), turning a doorknob (Knob), cutting with a knife (Knife), brushing with a toothbrush (Toothbrush), holding a thick book (Book) after we attached five force sensitive resistor (FSR) sensors on the tip of fingers and four surface electromyogram (sEMG) electrodes on the lower arm of the subject’s dominant hand. Root Mean Square (RMS) and Mean Absolute Value (MAV) from the mean maximum values of sEMG(%) and fingertip force(kgf) of all ten subjects were extracted as features. The classification from the feature dataset using convolutional neural network (CNN) was applied and analyzed the results of accuracy and repeatability. The mean maximum values of EMG and fingertip forces during five different grasp tasks, and the MAV and RMS which were extracted features from the above were compared with task pairs. They showed significant differences in comparison of four pairs of tasks which were Bottle and Knife (p = 0.005 in both MAV and RMS), Bottle and Toothbrush (p = 0.005in both MAV and RMS), Bottle and Book (p = 0.013 in both MAV and RMS), Knob and Toothbrush (p = 0.047 in MAV and p = 0.028 in RMS). The classification accuracy of the Bottle grasp task was the largest at 60% (true positive predictive rate is 60% and false postive rate is 40%), while the other tasks showed an 30-40% of accuracy. Repeatability was 60% in the Bottle task and 50% in the Knob task, and those of the other tasks were ranged 30-40%. Overall, it is believed that the small number of samples in the study is the main reason of the low accuracy and repeatability of the classification. A total of nine variables (four sEMG and five forces) showed different significances in paired mean comparisons for five grasp tasks (graspping a bottle, turning a doorknob, cutting with a knife, brushing teeth with a toothbrush, holding a thick book). A comparison of the reduced variable from feature extraction also showed different classification accuracy for five grasp tasks.

주차 시간 단축 및 정확도 향상을 위한 카메라 모듈 보조장치의 구조화 성능 향상 방안

이민구(Mingu LEE),박주현(Juhyun Park) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

Around view Monitor is the system for helping driver find exact position while parking the car, reflecting visual aspects from four-outside cameras around the vehicle. Front and rear, left and right, there are two couples of distinguished cameras settled in order to reveal the obstacles outside the vehicle. The object appeared around the vehicle is captured artificially as if we look around the vehicle in the view above it, like in the sky, in real-time. Problem occurred on the angle of camera on the present monitoring system, which is determined and distinguished according to length and width of each vehicle model. Several vernacular approaches for deciding angles of monitoring camera were in common. Because of physical volume of each vehicle, four-point camera setting was customized only for the only model of the vehicle. Instead, a size-oriented approach for automatic deciding angles of camera is presented in this paper. This approach calls for the determination of available angle configurations and calibrations, which is based on the link and joint coordinate systems and robot arm mechanism. These adjustments are presented in two accurate mathematical ways to permit the production of mounting construction indicators and their relative motion equations. The construction indicators, (representing adaptive lengths and angles of settlement links) are configured by factory setup for the purpose of jointing four cameras for monitoring. This paper describes on the calculation of a simplified three-dimensional mathematical model of vehicle cameraattachments for the purpose of developing real-time parking guide system, and applying the parking environment to several different characteristics of vehicle models. Several vehicle models include three fixed scales which are representing the car-length, car-width, and height of cameras. Determination of positions of the four cameras can be presented in the form of matrix calculation of kinematics and motion variables as well as angle-sequenced graphics in the modeling of ghost view frames of the occupant configuration within the vehicle exterior system.

Fabrication of Graphene Thin Films Based on Layer-by-Layer Self-Assembly of Functionalized Graphene Nanosheets

Park, Je Seob,Cho, Sung Min,Kim, Woo-Jae,Park, Juhyun,Yoo, Pil J. American Chemical Society 2011 ACS APPLIED MATERIALS & INTERFACES Vol.3 No.2

<P>In this study, we present a facile means of fabricating graphene thin films via layer-by-layer (LbL) assembly of charged graphene nanosheets (GS) based on electrostatic interactions. To this end, graphite oxide (GO) obtained from graphite powder using Hummers method is chemically reduced to carboxylic acid-functionalized GS and amine-functionalized GS to perform an alternate LbL deposition between oppositely charged GSs. Specifically, for successful preparation of positively charged GS, GOs are treated with an intermediate acyl-chlorination reaction by thionyl chloride and a subsequent amidation reaction in pyridine, whereby a stable GO dispersibility can be maintained within the polar reaction solvent. As a result, without the aid of additional hybridization with charged nanomaterials or polyelectrolytes, the oppositely charged graphene nanosheets can be electrostatically assembled to form graphene thin films in an aqueous environment, while obtaining controllability over film thickness and transparency. Finally, the electrical property of the assembled graphene thin films can be enhanced through a thermal treatment process. Notably, the introduction of chloride functions during the acyl-chlorination reaction provides the p-doping effect for the assembled graphene thin films, yielding a sheet resistance of 1.4 kΩ/sq with a light transmittance of 80% after thermal treatment. Since the proposed method allows for large-scale production as well as elaborate manipulation of the physical properties of the graphene thin films, it can be potentially utilized in various applications, such as transparent electrodes, flexible displays and highly sensitive biosensors.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2011/aamick.2011.3.issue-2/am100977p/production/images/medium/am-2010-00977p_0001.gif'></P>

Controlled wavelength reduction in surface wrinkling of poly(dimethylsiloxane)

Park, Jeong-Yong,Chae, Hee Yeop,Chung, Chan-Hwa,Sim, Sang Jun,Park, Juhyun,Lee, Hong H.,Yoo, Pil J. Royal Society of Chemistry 2010 SOFT MATTER Vol.6 No.3

<P>In this paper, we report that the wavelength of a wrinkled PDMS structure decreases upon annealing by combinative treatments of ultraviolet/ozone irradiation and oxygen plasma (case I). The wavelength of wrinkles also decreases when the PDMS surface is subjected to repeated exposure to a short-period oxygen plasma (case II). As opposed to other studies in which the wrinkling wavelength grows with processing time or temperature, some notable characteristics of wavelength reduction are observed in this study. Two routes toward decreasing the wavelength are associated with two different conditions of the PDMS surface. The former can be ascribed to a strain increase during the post-annealing procedure on a viscoelastic intermediate layer and for the latter, on the other hand, the selective hardening of an elastic intermediate layer controls the wavelength reduction. Elemental depth profiles obtained from Auger electron spectroscopy and nano-indentation of the surface by atomic force microscopy are employed to confirm these explanations. We also find that an externally applied stress can cause secondary wrinkling on a global scale, leading to a hierarchical structure with two wavelength scales. The proposed experimental results provide a new means of tailoring the surface morphology of wrinkled structures on demand.</P> <P>Graphic Abstract</P><P>Novel means to manipulate the wrinkling characteristics of PDMS surface are presented. Post annealing after UVO/plasma treatment or repetitive short-period plasma treatments affects the mechanical properties of intermediate PDMS layer, whereby the wrinkling wavelength can be reduced. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b916603c'> </P>

Robust stability analysis for Lur’e systems with interval time-varying delays via Wirtinger-based inequality

Park, Myeongjin,Kwon, Ohmin,Park, Juhyun,Lee, Sangmoon,Cha, Eunjong Springer (Biomed Central Ltd.) 2014 Advances in Difference Equations Vol. No.

Effect of ozone concentration on atomic layer deposited tin oxide

Park, Hyunwoo,Park, Joohyun,Shin, Seokyoon,Ham, Giyul,Choi, Hyeongsu,Lee, Seungjin,Lee, Namgue,Kwon, Sejin,Bang, Minwook,Lee, Juhyun,Kim, Bumsik,Jeon, Hyeongtag American Institute of Physics 2018 Journal of Vacuum Science & Technology. A Vol.36 No.5

Design of a 22-nm FinFET-Based SRAM With Read Buffer for Near-Threshold Voltage Operation

Juhyun Park,Younghwi Yang,Hanwool Jeong,Seung Chul Song,Wang, Joseph,Yeap, Geoffrey,Seong-Ook Jung Institute of Electrical and Electronics Engineers 2015 IEEE transactions on electron devices Vol. No.

<P>A near-threshold voltage (V<SUB>th</SUB>) operation circuit is important for both energy- and performance-constrained applications. The conventional 6-T SRAM bit-cell designed for super-V<SUB>th</SUB> operation cannot achieve the target SRAM bit-cell margins such as the hold stability, read stability, and write ability margins in the near-V<SUB>th</SUB> region. The recently proposed SRAM bit-cells with read buffer suffer from the problems of low read 0 sensing margin and large read 1 sensing time in the near-V<SUB>th</SUB> region. This paper proposes a read buffer with adjusted the number of fins or V<SUB>th</SUB> to resolve the problems in the near-V<SUB>th</SUB> region. This paper also proposes a design method for pull-up, pull-down, and pass-gate transistors to achieve the target hold stability and presents an effective write assist circuit to achieve the target write ability in the near-V<SUB>th</SUB> region.</P>

Robust Controller Design for Uncertain Time-Delay Systems

Juhyun Doh,Juhyun Park,Sangchul Won 제어로봇시스템학회 1997 제어로봇시스템학회 국내학술대회 논문집 Vol.1997 No.10

ROBUST STABILIZATION OF TIME-DELAY SYSTEMS WITH NONLINEAR UNCERTAINTIES

Juhyun Park,Sangchul Won 제어로봇시스템학회 1996 제어로봇시스템학회 국내학술대회 논문집 Vol.2 No.10