• 제목/요약/키워드: Focus distance

검색결과 425건 처리시간 0.025초

An Analysis of the Strengths and Weaknesses of Seoul Fashion Week with a Focus on Organisational Issues

  • Kim, Hye Eun
    • 한국의류산업학회지
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    • 제17권6호
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    • pp.895-906
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    • 2015
  • Seoul Fashion Week aims to be the world’s fifth Fashion Week from the year after 2000. This has involved significant labour and investment, not all of which has been successful. This study analyses the strengths and weaknesses of SFW based on the London Fashion Week as a successful model. By identifying its obvious and less obvious characteristics, this analysis aims to diagnose SFW’s current status in order to upgrade the event at an international level. Key factors are organisational body, designers, visitors, sponsors, schedule, venue, main events and supportive events. The following points have emerged from the research: the success of Seoul Fashion Week was based on the combination of separate collections, an appropriate fashion show venue, and the active role of new designers. The problems were: lack of an independent organisation, non-professional staff, lack of diverse visitors, exclusive governmental funding, late timing, excessive distance from the main European and American fashion markets, lack of sustainability of the main events, a limited variety of supportive events, the absence of online promotion and, last but not least, no distinctive features. The study concludes that Seoul Fashion Week has great potential with its fast growth and young designers. This should be complemented with an independent organisation and effective administration and strategy.

마이크로폰 31개로 이루어진 선형배열 음향렌즈의 구성과 실험 (Development and Experiment of a Linear Array Acoustic Lens with 31 Microphones)

  • 현석봉;민동현;김수용
    • 한국음향학회지
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    • 제13권5호
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    • pp.15-23
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    • 1994
  • 31개의 마이크로폰이 34mm 간격으로 선형배열된 음향영상장치용 전자 렌즈를 제작하였다. 마이크로폰을 이용한 음향센서의 공진주파수는 20kHz이고, 16개의 마이크로폰은 수평으로 나머지 15개의 마이크로폰은 수직으로 배치되어 있어서, 음원의 2차원적인 각도를 알아낼 수 있고 음원의 운동을 실시간으로 추적할 수 있다. 이산 푸리어변환할때 ㅈ나타나는 aliasing 문제 때문에 제작된 렌즈의 최대 관찰가능각도는 15도로 제한된다. 또한 촛점을 맞추기 위해 직각위상 검파방법을 이용하였다. 무향실에서 PC를 이용하여 음향렌즈를 실험하였으며 음향영상이론과 일치하는 결과를 얻었다.

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PMDV-hop: An effective range-free 3D localization scheme based on the particle swarm optimization in wireless sensor network

  • Wang, Wenjuan;Yang, Yuwang;Wang, Lei;Lu, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권1호
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    • pp.61-80
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    • 2018
  • Location information of individual nodes is important in the implementation of necessary network functions. While extensive studies focus on localization techniques in 2D space, few approaches have been proposed for 3D positioning, which brings the location closer to the reality with more complex calculation consumptions for high accuracy. In this paper, an effective range-free localization scheme is proposed for 3D space localization, and the sensitivity of parameters is evaluated. Firstly, we present an improved algorithm (MDV-Hop), that the average distance per hop of the anchor nodes is calculated by root-mean-square error (RMSE), and is dynamically corrected in groups with the weighted RMSE based on group hops. For more improvement in accuracy, we expand particle swarm optimization (PSO) of intelligent optimization algorithms to MDV-Hop localization algorithm, called PMDV-hop, in which the parameters (inertia weight and trust coefficient) in PSO are calculated dynamically. Secondly, the effect of various localization parameters affecting the PMDV-hop performance is also present. The simulation results show that PMDV-hop performs better in positioning accuracy with limited energy.

후방산란(後方散亂)과 노출배수(露出倍數)에 관(關)한 검토(檢討) (Observation of Back Scattering and Exposure-Factors)

  • 허준;김창균;강홍석;이선숙;이좌룡;윤철호
    • 대한방사선기술학회지:방사선기술과학
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    • 제5권1호
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    • pp.15-19
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    • 1982
  • Authors made an experiment to know the relation of surface doses and multiple factors of exposure by using grids, fields, tube voltages objects and distances and obtained the results as follows: 1. Surface doses were increased in proportion to the thickness of objects. 2. Surface doses were more influenced when irradiated fields were small and tube voltages were low. 3. Surface doses were a logarthmic proportion to the focus-object distance. 4. Multiple factors of exposure by using grid were under the control of the thickness of objects, irradiated fields and tube voltages but the relation of them were not fixed.

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글라이딩하는 날치의 날개형상 및 성능에 관한 연구 (Investigation of the Wing Design and Performance of a Gliding Flying Fish)

  • 박형민;최해천
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.97-100
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    • 2008
  • Various flyers in nature have attracted great interests with a recent need for developing versatile and small-size flight vehicles. In the present study, we focus on the flying fish which has been observed to glide a long distance just above a seawater surface. Since previous studies have depended on the field observation or measurement of the physical parameters only, quantitative data of the flying fish flight has not been provided so far. Therefore, we evaluate the wing performance of the flying fish in gliding flight by directly measuring the lift, drag and pitching moment on real flying fish models (Cypselurus hiraii) in a wind tunnel. In addition, we investigate the roles of wing morphology like the enlarged pectoral and pelvic fins, and lateral dihedral angle of pectoral fins. With both the pectoral and pelvic fins spread, the lift-to-drag ratio is larger and the longitudinal static stability is enhanced than those with the pelvic fins folded. From the glide polar, we find that the wing performance of flying fish is equivalent to those of medium-size birds like the petrel, hawk and wood duck. Finally, we examine the effect of water surface underneath the flying fish and find that the water surface reduces the drag and increases the lift-to-drag ratio.

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PERSONAL SPACE-BASED MODELING OF RELATIONSHIPS BETWEEN PEOPLE FOR NEW HUMAN-COMPUTER INTERACTION

  • Amaoka, Toshitaka;Laga, Hamid;Saito, Suguru;Nakajima, Masayuki
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2009년도 IWAIT
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    • pp.746-750
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    • 2009
  • In this paper we focus on the Personal Space (PS) as a nonverbal communication concept to build a new Human Computer Interaction. The analysis of people positions with respect to their PS gives an idea on the nature of their relationship. We propose to analyze and model the PS using Computer Vision (CV), and visualize it using Computer Graphics. For this purpose, we define the PS based on four parameters: distance between people, their face orientations, age, and gender. We automatically estimate the first two parameters from image sequences using CV technology, while the two other parameters are set manually. Finally, we calculate the two-dimensional relationship of multiple persons and visualize it as 3D contours in real-time. Our method can sense and visualize invisible and unconscious PS distributions and convey the spatial relationship of users by an intuitive visual representation. The results of this paper can be used to Human Computer Interaction in public spaces.

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RFID 태그플로어 방식의 내비게이션에 관한 연구 (A Study on the RFID Tag-Floor Based Navigation)

  • 최정욱;오동익;김승우
    • 제어로봇시스템학회논문지
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    • 제12권10호
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    • pp.968-974
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    • 2006
  • We are moving into the era of ubiquitous computing. Ubiquitous Sensor Network (USN) is a base of such computing paradigm, where recognizing the identification and the position of objects is important. For the object identification, RFID tags are commonly used. For the object positioning, use of sensors such as laser and ultrasonic scanners is popular. Recently, there have been a few attempts to apply RFID technology in robot localization by replacing the sensors with RFID readers to achieve simpler and unified USN settings. However, RFID does not provide enough sensing accuracy for some USN applications such as robot navigation, mainly because of its inaccuracy in distance measurements. In this paper, we describe our approach on achieving accurate navigation using RFID. We solely rely on RFID mechanism for the localization by providing coordinate information through RFID tag installed floors. With the accurate positional information stored in the RFID tag, we complement coordinate errors accumulated during the wheel based robot navigation. We especially focus on how to distribute RFID tags (tag pattern) and how many to place (tag granularity) on the RFID tag-floor. To determine efficient tag granularities and tag patterns, we developed a simulation program. We define the error in navigation and use it to compare the effectiveness of the navigation. We analyze the simulation results to determine the efficient granularities and tag arrangement patterns that can improve the effectiveness of RFID navigation in general.

이중모드 위상도플러 속도계측기법에 의한 소형 액체로켓엔진 인젝터 분무의 가시화 (A Visualization of the Spray from Small Liquid-rocket Engine Injector by Dual-mode Phase Doppler Anemometry)

  • 정훈;김정수;배대석;권오붕
    • 한국가시화정보학회지
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    • 제8권4호
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    • pp.60-65
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    • 2010
  • A focus is given to the breakup behavior of spray droplets issuing from a nonimpinging-type injector. The analysis has been carried out experimentally by means of the dual-mode phase Doppler anemometry (DPDA). Spray characteristic parameters in terms of axial velocity, mean diameter, velocity fluctuation, and span (width of the size distribution) of droplets are measured down the geometric axis of a nozzle orifice and on the plane normal to the spray stream with the injection pressure variations. As the injection pressure increases, the velocity and its fluctuation become higher, whereas the droplet sizes get smaller. It is also shown that the magnitudes of those parameters are smoothed out by dispersion when the droplets move downstream as well as outwardly. The atomization process is significantly influenced by the injection pressure rather than the traveling distance in the experimental condition presented.

네오프렌 소재의 레이저 커팅기법 적용에 따른 물성 및 드레이프 형상 변화 연구 (A Study on Changes of Drape Shapes and Physical Properties by Applying Laser-Cutting Technique on Neoprene Materials)

  • 한유정;김종준
    • 패션비즈니스
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    • 제19권4호
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    • pp.109-119
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    • 2015
  • A wide variety of fashion materials focus on good drape property and softness. Among the recently emerging materials, Neoprene that consists of laminated knit on both sides of foamed neoprene sheet seeks a unique appearance that is considerably deviated from the current flow. Diverse processing methods for the newly released material heighten the value in function and beauty among trends of fashion materials by enhancing the appearance, touch and material property. Laser-cutting technique is one of the processing methods that is consistently used in the textile area. This study aimed to find the basic materials for applicability of laser-cutting technique to clothing goods after consideration of the changes in material property and drape shape, and to furthermore enforce different pattern conditions to Neoprene material, one of the newly attractive materials in the fashion area. In this study, we applied laser-cutting technique to Neoprene material sample under different conditions of pattern appearance, size and distance, based on current evaluation and theoretical background of Neoprene material, fashion trend and laser-cutting technique. Drape property can improve and the drape direction could also be controlled by a wide variety of laser-cutting techniques applied to Neoprene materials that have uniquely different appearances from most other textiles. This technique could be applied to the design for diversification of Neoprene clothing goods in the future.

A Study on Representation of 3D Virtual Fabric Simulation with Drape Image Analysis II - Focus on the Comparison between Real Clothing and 3D Virtual Clothing -

  • Lee, Min-Jeong;Sohn, Hee-Soon;Kim, Jong-Jun
    • 패션비즈니스
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    • 제15권3호
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    • pp.97-111
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    • 2011
  • This study aims to apply 3D virtual fabric parameters - as obtained from previous research experiments - to 3D virtual clothing simulation in comparing its similarity with actual clothing as worn, with a view to verifying the objectivity and validity of the 3D virtual fabric simulation method devised by the drape image analysis method. In addition, the result is intended to be used as the basic data for new 3D virtual clothing simulation methods. As the results, 3D virtual fabric parameters designed to simulate 3D drape to be similar to actual fabrics were found to be Bending Strength, Buckling Point, Density, Particle Distance, and Shear. They were also found to be important measurements when evaluating visual similarity between drape shadow images and number of nodes. 3D virtual fabric simulation method devised by the drape image analysis method was appropriate in extracting 3D fabric parameters with the reflection of actual fabrics' physical and dynamic characteristics, in connection with 3D virtual fabric simulation. 3D virtual fabric parameters with the reflection of actual fabrics' physical and dynamic characteristics using the proposed 3D virtual fabric simulation method are accumulated and provided as a standard, this will facilitate the introduction 3D virtual fabric simulation technology.