• Title/Summary/Keyword: shape functions

Search Result 1,034, Processing Time 0.028 seconds

Pulse Shape Design for Ultra-Wideband Radios Using Projections onto Convex Sets (POCS를 이용한 초광대역 무선통신의 펄스파형 설계)

  • Lee, Seo-Young
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.33 no.3A
    • /
    • pp.311-318
    • /
    • 2008
  • We propose new pulse shapes for FCC-compliant ultra-wideband (UWB) radios. The projections onto convex sets (POCS) technique is used to optimize temporal and spectral shapes of UWB pulses under the constraints of all of the desired UWB signal properties: efficient spectral utilization under the FCC spectral mask, time-limitedness, and good autocorrelation. Simulation results show that for all values of the pulse duration, the new pulse shapes not only meet the FCC spectral mask most efficiently, but also have nearly the same autocorrelation functions. It is also observed that our truncated (i.e., strictly time-limited) pulse shapes outperform the truncated Gaussian monocycle in the BER performance of binary TH-PPM systems for the same pulse durations. The POCS technique provides an effective method for designing UWB pulse shapes in terms of its inherent design flexibility and joint optimization capability.

Design of Haebaragi Park (해바라기 공원설계)

  • 박찬용
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.29 no.1
    • /
    • pp.32-40
    • /
    • 2001
  • The purpose of designing Haebaragi park, legally designated as children park, is to make a place for children including residents performing outdoor recreation, various social interactions, and cultural activities. Design concept for space plan have twofold; the one is a positive and creative playing space and facilities for children, escaped from a monotonous playground, and the other is a cultural and social space for neighboring communities. The site having the area of 1,316.7 square meters, located in Nowon-Dong, Buk-Gu, Daegu metropolitan City, is just like a vest pocket park. The adjacent area had been developed a slum area with mixed ad visually conflicting land use patterns and low income groups. The children and residents living in the area do not have any public space suitable for playing and/or rest. After analyzing such locational characteristic as accessibility, land use of the communities, and potentials for park development, and such design concept as arrangement of facilities, efficient use of site, and functional allocation of park space, We have mad a plan for composition of spaces for various activities, provision of facilities based on estimation of user-demand and activities, and planting. In the design process, we have tried to harmonize functional spaces with facilities, and to organize all the functions as a whole. To improve urbanity and aesthetic shape of park design, we have introduced a central plaza, design of a pave floor, a torrent, large trees for shade, colonnades and so on. From this design project, we can develop the site as a children park for increasing creativities and various playing opportunities, and as a resident space for rest, cultural activities. In the future, it is required that many attempt to design and develop urban small space as a park for children and residents.

  • PDF

A Study about the interactions of vessels running parallely proximity to one another and safe conducting of them (병항(竝航) 2선박간의 상호작용과 안전항과(安全航過)에 관한 연구)

  • Lee Chun-Ki;Yoon Jeom-Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2005.10a
    • /
    • pp.11-16
    • /
    • 2005
  • When a vessel passes near a channel boundary, the boundary creates forces and moments acting on the vessel. With the same reason passing of two vessels closely gives same effects to each other. The principal. difference between the above two cases is that the channel boundary is long and constant shape compared to those of vessels. The interaction forces and moments between two vessels could be assumed to be functions of the longitudinal distance $x_0$, transverse distance $y_0$ and speeds of the two vessels. Passage of one vessel close to another is important operationally from the viewpoint of replenishment at sea, avoidance of collisions and passage of two vessels in restricted channels. The authors studied the interactions between two vessels running closely and calculated safe conducting distances according to separated distances and speeds of the two vessels.

  • PDF

A Study on the Structural Characteristics and Metal Ornament of Jeonju-Jang (전주장의 구조적 특징과 금구장식 연구)

  • Baik, Da hee;Lim, Seung Taek
    • Journal of the Korea Furniture Society
    • /
    • v.28 no.3
    • /
    • pp.207-223
    • /
    • 2017
  • Jeonju-Jang is the wood furniture that was made in Chonbuk Jeonju province during the Joseon Dynasty, and was used by middle-upper social classes. It has value as a local cultural heritage because it has unique characteristics in terms of the shape of the furniture, the metal ornament and various functions are integrated in accordance with user's requirements. Therefore, the purpose of this study is to define the structural characteristics of the Jeonju-Jang through case studies of 16 existing artifacts in order to preserve and inherit the value as local cultural resources. The conclusion is as follows. First, Jeonju-Jang in the late period of Joseon Dynasty that is made up of one board to the bottom with the binding of the board. and the front wall, the Juibyuckkan and the Meoruemkan are omitted or made small, so the structure of the surface is simple. There are three or four drawers under the Cheon pan(top plate). There are drawers and shelf inside the hinged door. In the case of a two-layer type, there is a Gaegumeong type door which has half of one side hinged. Second, Jeonju-Jang of the Japanese Ruling Era had a Juibyuckkan by frame binding and an increase in the number of Meoruemkan. and it had independent legs. The Cheon-pan(top plate) was more left and right than both sides. Third, in the late Joseon Dynasty period as a feature of the metal ornaments, cast iron and yellow brass were used as materials. In the Japanese Ruling Era, nickel was mainly used. Various patterns were engraved and the number increased, and it became gorgeous surface as a whole.

Public Administration Town Plan of Sejong-City based on Landscape Ecological Perspectives (경관생태학적 관점에서의 세종시 중심행정타운 조성계획)

  • Lee, Ai-Ran
    • Ecology and Resilient Infrastructure
    • /
    • v.1 no.2
    • /
    • pp.94-101
    • /
    • 2014
  • This is the urban design master plan for the Public Administration Town. The project proposes a newly configured city, where environmental and democratic principles are expressed in the shape of the urban fabric. To achieve the goal, the concepts of 'Flat City, Link City, and Zero City' were introduced. These concept show "Space fabric arrange, connection and material circulation and flow from ecological landscape". 'Flat City' shaped the government buildings into an iconic plane, and democratic society. The iconic plane's surface extends across the whole city, creating an expansive public park, which is easily accessible, and open to nature. 'Link City' connects governmental agencies to enhance their function and interactions. Government facilities, parks and green spaces, cultural facilities, commercial zones, and residential districts areas create an interconnecting network. 'Zero City' has integrated infrastructure systems to reuse waste, reduce pollution, and provide essential city functions. It creates a new wildlife habitat, making 'Zero City' a good neighborhood. This proposal was made to integrate historical, regional, nature experiences with various approaches in architecture, city, and landscape architecture.

An Vision System for Traffic sign Recognition (교통표지판 인식을 위한 비젼시스템)

  • Kim, Tae-Woo;Kang, Yong-Seok;Cha, Sam;Bae, Cheol-Soo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.2 no.2
    • /
    • pp.45-50
    • /
    • 2009
  • This paper presents an active vision system for on-line traffic sign recognition. The system is composed of two cameras, one is equipped with a wide-angle lens and the other with a telephoto lends, and a PC with an image processing board. The system first detects candidates for traffic signs in the wide-angle image using color, intensity, and shape information. For each candidate, the telephoto-camera is directed to its predicted position to capture the candidate in a large size in the image. The recognition algorithm is designed by intensively using built in functions of an off-the-shelf image processing board to realize both easy implementation and fast recognition. The results of on-road experiments show the feasibility of the system.

  • PDF

Counter-Current Flow Limitation Model Based on the Hyperbolic Two-fluid Equations and Interface Shape Function (쌍곡선형 이상유동 방정식과 경계면 모양함수를 이용한 유체기계의 역류유동제한점 예측방법 개발)

  • 정지환
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.1 no.1
    • /
    • pp.15-22
    • /
    • 2000
  • There are lots of industrial machines of which functions are achieved by operation of multi-phase fluids. Some of them take advantage of the characteristics of counter-current two-phase flow The maximum flow rates of gas and liquid phases which flow in opposite-directions (counter-current flow) are limited by a phenomenon known as a Counter-Current Flow Limitation (CCFL or Flooding) The mass and momentum conservation equations for each Phase were established to build a first-order hyperbolic partial derivative equations system. A new CCFL model is developed based on the characteristic equation of the hyperbolic PDE system. The present model has its applicationto the case in which a non-uniform flow is developed around a square or sharp-edged entrance of liquid phase. The model is able to he used to Predict the operating-limit of components in which mass and heat transfer are taking place between liquid and gas phases.

  • PDF

New Performance Evaluation Method of Focused Ultrasonic Transducers By Using Virtual 3D Graphic (가상 3D 그래픽을 이용한 집속형 초음파 탐촉자 성능평가 방법)

  • Lee, Sun-Heum;Choi, Kwan-Sun;Kim, Dong-Sik
    • The KIPS Transactions:PartB
    • /
    • v.14B no.6
    • /
    • pp.407-412
    • /
    • 2007
  • The performance of ultrasonic testing systems for industrial or medical purpose largely depends on the performance of ultrasonic transducers. Generally, the information about an ultrasonic transducer performance characteristics are expressed by the ultrasonic R/F signal back from a reflector and its frequency characteristics in the data sheet provided by manufacturers. In case of focused ultrasonic transducers, the two pieces of information can, however, hardly assure that the focused ultrasonic transducer would produce well-focused C-scan images. Therefore, we propose the measured size of focal spot and the reconstructed shape of effective focal zone in the focused sound field as novel measures for the performance evaluation of the focused ultrasonic transducers. The process of getting the both measures of the transducers is conducted by the implemented software including sound field scanning and virtual 3D reconstruction functions which requires the echo of a point reflector. The proposed method could, otherwise impossible in the existing method, effectively and simply distinguish superior ones among many transducers made in the same specification and be also used to detect the performance degradation due to the aging of the transducers. Eventually, the quality of performance of the ultrasonic testing systems for industrial or medical purpose is secured.

Study about Yukmigiwhangwon in the Point of Hyungsang Medicine (육미지황원(六味地黃元)의 형상의학적(形象醫學的) 고찰)

  • Kang, You-Sik;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.20 no.5
    • /
    • pp.1089-1101
    • /
    • 2006
  • Following conclusions are drawn from study about Yukmigiwhangwon through referring to literatures and reviewing in the point of Hyungsang medicine. Yukmigiwhangwon was prescribed by Jeon Eul in order to cure five kinds of flaccidity of infants, but after since then it has been basically applied to symptoms which was caused by deficiency of the kidney not only infants but also adult. The deficiency of kidney is the lack of vital essence and body fluid stored in kidney, it happens because infants are born in the conditions of lack of receiving in the womb. And it happens because adults infringe the rules of life, especially the sexual life. Main symptoms of the poverty of renal functions are emptiness of the brain marrow, dizziness, forgetfulness, tinnitus, deafness, vertigo and dim eyesight, insomnia, the low back and knees aching and limping, heat on the legs, tibia aching, nocturnal emission, dry mouth, reddened tongue and little coating or non coating of the 'tongue, weak blood meridians. the treating method is nourishing Eum and supplementing kidney. In Dongeuibogam Yukmigiwhangwon is mentioned in the parts of vital essence, blood, voice, kidney, urine, eye, ear, the low back, hair, fire, exhaustion syndrome, cough, polydipsia, infant, etc. The shapes which Yukmigiwhangwon is applied to are the Dam Body Doing deficiency of Eum due to excess of Yang, man, infant, Jung type, Fish group, reverse triangular shape, big headed man, big eared man, big mouthed man, man having prominent cheekbones, man having long waist, man having big hips, man with thick hair or white hair, man with bald on the head, etc. In color it is applied to darkish complexion, flushed tip of the nose, or flushed cheek bones. Through inquiring into the clinical cases on the points of Hyungsang medicine Yukmigiwhangwon is efficacious cure to lumbago, symptoms of tendons and bones, symptoms of eyes and ears, symptoms of respiratory organs, dermatopathia, headache, polydipsia, urinary disorders, etc.

Free Vibrations of Arches in Cartesian Coordinates (직교좌표계에 의한 아치의 자유진동)

  • Lee, Byoung-Koo;Lee, Yong-Soo;Kim, Il-Jung;Choi, Kou-Moon
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.12 no.12
    • /
    • pp.970-978
    • /
    • 2002
  • The differential equations governing free vibrations of the elastic arches with unsymmetric axis are derived in Cartesian coordinates rather than in polar coordinates. in which the effect of rotatory inertia is included. Frequencies and mode shapes are computed numerically for parabolic arches with both clamped ends and both hinged ends. Comparisons of natural frequencies between this study and SAP 2000 are made to validate theories and numerical methods developed herein. The convergent efficiency is highly improved under the newly derived differential equations in Cartesian coordinates. The lowest four natural frequency parameters are reported, with and without the rotatory inertia, as functions of three non-dimensional system parameters the rise to chord length ratio. the span length to chord length ratio, and the slenderness ratio. Also typical mode shapes of vibrating arches are presented.