• Title/Summary/Keyword: E Field Distribution

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SAR Analysis for Test Positions of Mobile Phone (휴대전화의 시험위치에 따른 SAR 분석)

  • 최형도;이애경;조광윤;오학태
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.7
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    • pp.1199-1205
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    • 2001
  • There has been an increase in the public concern about possible health risks by electromagnetic exposure from mobile phones. Recently, several SAR measurement procedures have been proposed to demonstrate the compliance of mobile phone with safety limits. To determine the maximum localized SAR of a test mobile phone, the electric field distribution is measured in the head phantom with simulated tissue liquid using the probe The important parameters in SAR measurement are the E-field probe, the shape and size of phantom, the electrical parameters of simulated tissue liquid, and test position, etc. Therefore, in order to setup the measurement standard, the studies on these factors are required. In this paper, the effects of the maximum localized SAR on the test positions of mobile phones were analyzed by the numerical computation and the SAR measurement. From the results, the worst condition of commonly used positions was determined and the touch and tilted positions were adopted as test positions of the domestic SAR measurement standard.

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Path Following Behavior of Crowd (군중의 경로 추적 행동)

  • Yi, Ji-hyeon
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.10-14
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    • 2008
  • Computer-animated crowd scenes are often observed in computer games and feature films. The common way to model locomotion of large human crowds is to employ agent based methods where the behavior of each person is independently modeled. But for large crowds, it is difficult for a user to control all the individuals using individual behavior model. Instead, crowd behaviors can be controlled more intuitively at the group level than at the individual level. In this paper, we present the group force field model to simulate path following behavior for groups. A group is a set of characters who have the same goals, i.e. the same path to follow. We also define three characteristics of grouping behavior: alignment, cohesion, and distribution. Our group force field model preserves these characteristics while avoiding collisions. By using our model, user can generate desired group behaviors from line-up behavior to lumped one.

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How are S0 galaxies formed? A case of the Sombrero galaxy

  • Kang, Jisu;Lee, Myung Gyoon;Jang, In Sung;Ko, Youkyung;Sohn, Jubee;Hwang, Narae;Park, Byeong-Gon
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.38.2-38.2
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    • 2019
  • S0 galaxies are mostly known to be formed in dense environments from spiral progenitors. Recently, however, a new formation scenario has been suggested that field S0s can be formed from elliptical progenitors. The Sombrero galaxy (M104, NGC 4594) is a massive disk galaxy located in the field environment, and its morphological type has been controversial from Sa to E. Thus, it is an ideal target to test the new scenario. We trace the giant halo of M104 with globular clusters to test this scenario. From the wide images obtained with CFHT/MegaCam, we find a large number of globular clusters in this galaxy. We also confirm their membership by measuring the radial velocities from the spectra obtained with MMT/Hectospec. The color distribution of these globular clusters is bimodal, and blue (metal-poor) globular clusters are more spatially widely spread than red (metal-rich) globular clusters. This indicates that M104 hosts a giant metal-poor halo as well as an inner metal-rich halo. Combining this result with the fact that M104 is unusually massive and brighter than other spiral galaxies, we infer that M104 was indeed a massive elliptical galaxy that had formed a metal-rich halo by gas-rich mergers and a metal-poor halo by gas-poor mergers. In addition, we find young star clusters around the disk of M104, which shows that the disk formed after the spheroidal halos had formed. In conclusion, we suggest that M104 was originally a massive elliptical galaxy and was transformed to a lenticular galaxy by acquiring its disk later.

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Mathematical formulations for static behavior of bi-directional FG porous plates rested on elastic foundation including middle/neutral-surfaces

  • Amr E. Assie;Salwa A. Mohamed;Alaa A. Abdelrahman;Mohamed A. Eltaher
    • Steel and Composite Structures
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    • v.48 no.2
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    • pp.113-130
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    • 2023
  • The present manuscript aims to investigate the deviation between the middle surface (MS) and neutral surface (NS) formulations on the static response of bi-directionally functionally graded (BDFG) porous plate. The higher order shear deformation plate theory with a four variable is exploited to define the displacement field of BDFG plate. The displacement field variables based on both NS and on MS are presented in detail. These relations tend to get and derive a new set of boundary conditions (BCs). The porosity distribution is portrayed by cosine function including three different configurations, center, bottom, and top distributions. The elastic foundation including shear and normal stiffnesses by Winkler-Pasternak model is included. The equilibrium equations based on MS and NS are derived by using Hamilton's principles and expressed by variable coefficient partial differential equations. The numerical differential quadrature method (DQM) is adopted to solve the derived partial differential equations with variable coefficient. Rigidities coefficients and stress resultants for both MS and NS formulations are derived. The mathematical formulation is proved with previous published work. Additional numerical and parametric results are developed to present the influences of modified boundary conditions, NS and MS formulations, gradation parameters, elastic foundations coefficients, porosity type and porosity coefficient on the static response of BDFG porous plate. The following model can be used in design and analysis of BDFG structure used in aerospace, vehicle, dental, bio-structure, civil and nuclear structures.

Seasonal Distribution, Egg Production and Feeding by the Marine Copepod Calanus sinicus in Asan Bay, Korea

  • Park, Chul
    • Journal of the korean society of oceanography
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    • v.32 no.2
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    • pp.85-92
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    • 1997
  • Seasonality in abundance and egg production was investigated for Calanus sinicus in Asan Bay, Korea, and feeding effort was measured in the laboratory condition. Although abundances of this species in this bay showed only one Peak in spring, egg Production showed two peaks, spring and fall, in this bay. Potential of year-round egg Production was also found. Food availability judged by the particulate organic carbon (POC) concentration was usually more than enough in this bay. High egg Production in fall resulted in spring Peak in abundance. But high egg Production in spring did not result in summer or fall Peak in abundance. Low abundances in summer and fall were believed to be the result of long range horizontal migration out to the central Part of the Yellow Sea. The highest average egg Production by the Population of this species was 16.3 eggs female-'day-'. Maximum e99 Production by an individual was 39.0 e99s female$^{-1}$ day$^{-1}$, which yielded 30.7% of specific egg Production rate in terms of body carbon content with the carbon contents of 44.44$^{\mu}$gC and 0.35 $^{\mu}$gC for individual adult female and egg, respectively. Clearance rate (F) measured in the laboratory condition decreased exponentially with the increase of food concentrations, as expected. The asymptote of F was 3.17 ml copepod$^{-1}$ h$^{-1}$. When this value and the minimum concentration of POC measured in the field were applied under the assumption of continuous feeding in the nature, the calculated gross efficient of egg production was 41.6% in case of average egg production of the population. Violation of the assumption of diurnal feeding rhythm and application of the minimum concentration of POC may offset the influence on calculation each other.

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Temporal and Spatial Variability of Chlorophyll a in the Northern East China Sea using Ocean Color Images in Summer (해색영상을 이용한 동중국해 북부해역 하계 클로로필 a의 시공간 분포)

  • Kim, Sang-Woo;Lim, Jin-Wook;Jang, Lee-Hyun
    • Journal of Environmental Science International
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    • v.17 no.1
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    • pp.85-95
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    • 2008
  • Temporal and spatial variabilities of chlorophyll a (Chl-a) in the northern East China Sea (ECS) are described, using both 8-day composite images of the SeaWiFS (Sea-viewing Wide Field-of-view Sensor) and in-situ data investigated in August and September during 2000-2005. Ocean color imagery showed that Chl-a concentrations on the continental shelf within the 50 m depth in the ECS were above 10 times higher than those of the Kuroshio area throughout the year. Higher concentrations (above $5mg/m^3$) of yearly mean Chl-a were observed along the western part of the shelf near the coast of China. The standard deviation also showed the characteristics of the spatial variability near $122-124^{\circ}E$, where the western region of the East China Sea was grater than that of the eastern region. Particularly the significant concentration of Chl-a, up to $9mg/m^3$, was found at the western part of $125^{\circ}E$ in the in-situ data of 2002. The higher Chl-a concentrations of in-situ data were consistent with low salinity waters of below 30 psu. It means that there were the close relationship between the horizontal distribution of Chl-a and low salinity water.

Assessment of the Anchor Head System Embedded in the Ground Surface (지표면에 근입한 앵커두부처리 시스템의 적용성 평가)

  • Min, Kyoung-Nam;Bae, Woo-Seok;Ahn, Kwang-Kuk;Jeong, Ku-Sic
    • The Journal of Engineering Geology
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    • v.22 no.1
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    • pp.49-58
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    • 2012
  • Anchor heads a recommonly exposed to surface weathering processes that cause physical damage by vibration and external forces. This study presents a new method of anchor-head installation that uses near-surface embedding based on analyses of concrete block failure. ABAQUS 3D numerical modeling performed to compare this method with the standard technique and to analyze the distribution of displacement and the stress pattern. In addition, application of the method to a real-world case was tested by in-situ measurements. The results show a maximum vertical stress of 9.73 MPa and vertical displacement of 1.34 mm. Field tests indicated that displacement of a concrete block was 3 to 4 times greater than that of an embedded bearing plate.

A study on Convergence of the Digital Contents Industry and Possibility of Exportation (디지털콘텐츠 산업의 융합화와 수출 가능성)

  • Chun, Byung-June;Choi, Dong-Gil
    • International Commerce and Information Review
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    • v.12 no.3
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    • pp.55-78
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    • 2010
  • This study analyses recent development of digital contents industry. The purpose of this study is to show how the convergence phenomenon is occurring in the digital contents industry. Furthermore, this study examines the influence of digital convergence on the digital contents industry. The characteristics of the digital contents industry falls roughly into three features. To begin with, technical aspect of the industrial feature is that digitalized contents can be used in various digital devices, namely OSMU(One Source Multi Use). The second feature is related to protection of copyright against illegal file sharing and downloading. One final point is that platform for distribution channels has been universal by digital convergence. To sum up, the notable feature of digital contents industry is high value-added. Also, digital contents industry is composed of users, digital device, network, and universal contents. Users are the key component of digital contents industry, who is distinguished from consumers. Digital devices such as mobile phone, PDA can play all kinds of digital contents and make users communicate in two-ways. Portable devices also allow the users to consume digital contents at any place. Digital contents can be distributed by both wire and wireless networks. And most of transactions can be made through networks. There are three key issues about digital convergence. Entry barriers for market become lowered; the age of contents users is changed from old generation to young generation. And the form of contents devices is changing rapidly. Traditional contents field such as movie, music, broadcasting, publishing, animations are combined into one digital contents territory. As a result, this paper suggests that digital convergence phenomenon will be accelerating for the future. According to the result of this study, the advent of digital convergence and e-Commerce will have significant influence on trade of digital contents.

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Comparison of Design Preferences in the Hawaiian Shirt and Current Market

  • Bahng, Youngjin;Reilly, Andrew
    • Fashion & Textile Research Journal
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    • v.20 no.4
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    • pp.379-388
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    • 2018
  • The Hawaiian shirt, also known as the Aloha shirt, is a short-sleeved, colorful shirt with traditional Polynesian designs (e.g., hibiscus, fish) originating in Hawai'i. The shirt was selected for study because it is a unique garment that originated in the Hawaiian Islands in the late $19^{th}$ and $20^{th}$ centuries and marketed as a tourist product but was eventually adopted as appropriate residential clothing by the $mid-20^{th}$ century, however with different aesthetic details. Today, it is assumed by Hawaiian Island residents that tourists demonstrate poor taste when selecting a Hawaiian shirt. The purposes of this study are to examine the validity of the assumption that tourist taste and resident taste in Hawaiian shirts are different and to investigate the current Hawaiian shirt market change. For this study, 555 questionnaires were obtained from tourists and residents, and 10 Hawaiian shirt retailers/wholesalers participated in in-depth interviews. The results indicated that differences do exist between tourists' and residents' preferences for print designs and colorway. The market change of Hawaiian shirts was also recognizable in that an increasing number of tourists select Hawaiian shirts similar to resident customers, as part of their routine lives rather than as holiday or vacation garments. Other differences in Hawaiian shirt shopping behavior included the findings that tourists consider fabrication less important than resident customers who consider fabrication more (i.e., cotton 100%). By using both quantitative and qualitative methods, this study contributes to the fashion design and marketing field as well as help manufacturers and retailers with their merchandise and distribution plans.

Design and embodiment of XrML Document editing system for digital contents copyright administration (디지털 컨텐츠 저작권 관리를 위한 XrML 문서편집 시스템의 설계 및 구현)

  • 임지훈;강치원;정회경;최범석;홍진우
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.368-372
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    • 2002
  • Channel of distribution of contents of digitalised multimedia contents is changing in form passed directly to consumer from manufacturer through digital network of high speed. Together, diffusion of various digital equipment that do is changing Past multimedia consumption structure with the wonderful speed so that can consume easily digital contents. Specially, Multimedia Personal Computer and fast diffusion of a digital television are acting role such as catalyst that promote easy purchase and consumption of multimedia contents of good qualify. However, this system is no method that can sell digital contents and express right that original owner for the contents can insist nothing but consume. Because consumer can distribute to another person copying contents that buy because of and user can distribute producing ashes again according to necessary field by oneself as well as, can lose meaning for original contents. In this paper, Text editing system for XrML (extensible Rights Markup Language) that describe about integrity of message and entity authentication in addition to necessary rights, fees, condition etc. and this to do fetters XML (eXtensible Markup Language) for copyright protection for digital contents in treatise that see hereupon and use digital contents design and embody.

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