• Title/Summary/Keyword: Overlap area

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Molecular Dynamics Simulation for Monolayers of Alkyl Thiol Molecules at Air-Solid Interfaces

  • 이송희;김한수
    • Bulletin of the Korean Chemical Society
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    • v.17 no.8
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    • pp.700-706
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    • 1996
  • We present the results of molecular dynamics simulations of monolayers of long-chain alkyl thiol [S(CH2)15CH3] molecules on an air-solid interface using the extended collapsed atom model for the chain-molecule and a gold surface for the solid surface. Several molecular dynamics simulations have been performed on monolayers with areas per molecule ranging from 18.30 to 32.10 Å2/molecule. It is found that there exist three possible transitions: a continuous transition characterized by a change in molecular configuration without change in lattice structure, a sudden transition characterized by the distinct lattice defects and perfect islands, and a third transition characterized by the appearance of a random, liquid-like state. The analysis of probability distributions of the segments shows that the structure of the chain-molecules at the air-solid interface is completely different from that at the air-water interface in the view of the degree of overlap of the probability distributions of the neighbor segments. The calculated diffusion coefficients of the chain-molecules on the monolayers seem to be not directly related to any one of the three transitions. However, the large diffusion of the molecules enhanced by the increment of the area per molecule may induce the second transition.

Recent Progress and Prospect of Luminescent Solar Concentrator (발광형 태양광 집광기 최신 연구 동향)

  • Song, Hyung-Jun
    • Journal of the Korean Solar Energy Society
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    • v.39 no.4
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    • pp.25-39
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    • 2019
  • Luminescent solar concentrator (LSC), consisting of luminophore included glass or substrate with edge-mounted photovoltaic cell, is semi-transparent, energy harvesting devices. The luminophore absorbs incident solar light and re-emit photons, while the waveguide plate allows re-emitted photons to reach edge or bottom mounted photovoltaic cells with reduced losses. If the area of LSC is much larger than that of photovoltaic cell, this system can effectively concentrate solar light. In order to improve the performance of LSC, new materials and optical structures have been suggested by many research groups. For decreasing re-abosprion losses, it is essential to minimize the overlap between absorption and photoluminescence solar spectrum of luminophoroe. Moreover, the combination of selective top reflector and reflective optical cavity structure significantly boosts the waveguide efficiency in the LSC. As a result of many efforts, commercially available LSCs have been demonstrated and verified in the outdoor. Also, it is expected to generate electricity in buildings by replacing conventional glass to LSCs.

Analysis of Power Characteristics of High-Power Shingled Photovoltaic Module with Color Application (고출력 슁글드 태양광 모듈 컬러 적용에 따른 출력 특성 분석)

  • Kim, Juhwi;Lee, Jaehyeong
    • Current Photovoltaic Research
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    • v.10 no.3
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    • pp.73-76
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    • 2022
  • BIPV (Building Integrated Photovoltaic) supplemented the minimum area problem required when installing existing solar modules. However, in order to apply it to buildings, research was needed to increase the aesthetics of solar modules and use them as a design. Accordingly, modules with color applied to the entire surface of the photovoltaic module were being developed, but there was a disadvantage of low power. Therefore, by dividing and bonding the cell strips, it was possible to improve the output power by applying a shingled technology in which other divided cells overlap in a busbar region where light couldn't be received. Shingled technology was advantageous for color modules because the front busbar part that degrades aesthetics was removed. In this research, four color shingled solar modules (Green, Yellow, Blue, Gray) were manufactured and power degradation was analyzed by measuring transmittance and reflectance. Gray color had 80.83% transmittance, which was 31.31% higher than Yellow, resulting in a power difference of 4.45 W.

A Method of Hierarchical Address Autoconfiguration base on Hop-count in 6LoWPAN (6LoWPAN에서 홉-수 기반 계층적 자동주소할당 방법)

  • Kim, Dong-Kyu;Kim, Jung-Gyu
    • Journal of Korea Society of Industrial Information Systems
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    • v.15 no.3
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    • pp.11-21
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    • 2010
  • Increase in the number of sensor nodes in sensor networks and sensor node to automatically assign addresses are needed. The method developed to address existing severe wasting, coordinators have all address information, each sensor node when addressing the shortcomings are a lot of traffic. In this paper, 6LoWPAN automatically from the sensor nodes capable of efficiently addressing Hop-Count based hierarchical address allocation algorithm is proposed. How to propose a hop-count of divided areas are separated, with no overlap and can be assigned a unique address, DAD(Duplicate Address Detection) reduced area. Perform DAD to reduce traffic, packet transmission in the IP header destination address, respectively, with a minimum 32-bit compression and packet transmission over a non-compression method to reduce the number of 11.1%.

Mechanism of Surface Corrosion in the Continuous Casting Guide Rolls

  • Fazlollah Sadeghi;Tahereh Zargar;Yoon-Uk Heo;Jae Sang Lee;Dong-Yong Park;NamKyu Park;Dae Geun Hong;Chang Hee Yim
    • Journal of Korea Foundry Society
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    • v.43 no.2
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    • pp.55-63
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    • 2023
  • Due to the importance of the surface on the final slab quality, it is essential to maintain a smooth segment roll surface that is in touch with the thin solid shell during solidification. In this paper, the surface of the used continuous casting guide roll was analyzed to realize the mechanism of its surface deterioration. Surface analysis has revealed severe corrosion at two distinct areas leading to deep roughness occurring on the guide roll. Firstly, the severe corrosion follows prior austenite grain boundary due to exposure with acidic environment. Also, in heat affected zone (HAZ) where two cladding beads overlap, more severe corrosion takes place. The overheat input results in local ferritization without full melting which increases retained δ-ferrite content almost 10 times higher than surrounding area. Corrosion was observed to happen at the δ-γ interface where Cr depletion takes place.

Cluster Topology Algorithm for Efficient Data Transmission in Wireless Body Area Network based on Mobile Sink (WBAN 환경에서 효율적인 데이터 전송을 위한 모바일 싱크기반의 클러스터 토폴로지 알고리즘)

  • Lee, Jun-Hyuk
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.12
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    • pp.56-63
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    • 2012
  • The WBAN technology means a short distance wireless network which provides each device interactive communication by connecting devices inside and outside of body. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. Wireless body area network is usually configured in energy efficient using sensor and zigbee device due to the power limitation and the characteristics of human body. Wireless sensor network consist of sensor field and sink node. Sensor field are composed a lot of sensor node and sink node collect sensing data. Wireless sensor network has capacity of the self constitution by protocol where placed in large area without fixed position. Mobile sink node distribute energy consumption therefore network life time was increased than fixed sink node. The energy efficient is important matter in wireless body area network because energy resource was limited on sensor node. In this paper we proposed cluster topology algorithm for efficient data transmission in wireless body area network based mobile sink. The proposed algorithm show good performance under the advantage of grid routing protocol and TDMA scheduling that minimized overlap area on cluster and reduced amount of data on cluster header in error prone wireless sensor network based on mobile sink.

한강하류지형면의 분류와 지형발달에 대한 연구 (양수리에서 능곡까지)

  • Park, No-Sik
    • Journal of the Speleological Society of Korea
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    • no.68
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    • pp.23-73
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    • 2005
  • Purpose of study; The purpose of this study is specifically classified as two parts. The one is to attempt the chronological annals of Quaternary topographic surface through the study over the formation process of alluvial surfaces in our country, setting forth the alluvial surfaces lower-parts of Han River area, as the basic deposit, and comparing it to the marginal landform surfaces. The other is to attempt the classification of micro morphology based on the and condition premising the land use as a link for the regional development in the lower-parts of Han river area. Reasons why selected the Lower-parts of Han river area as study objects: 1. The change of river course in this area is very serve both in vertical and horizontal sides. With a situation it is very easy to know about the old geography related to the formation process of topography. 2. The component materials of gravel, sand, silt and clay are deposited in this area. Making it the available data, it is possible to consider about not oかy the formation process of topography but alsoon the development history to some extent. 3. The earthen vessel, a fossil shell fish, bone, cnarcoal and sea-weed are included in the alluvial deposition in this area. These can be also valuable data related to the chronological annals. 4. The bottom set conglometate beds is also included in the alluvial deposits. This can be also valuable data related to the research of geomorphological development. 5. Around of this area the medium landform surface, lower landform surface, pediment and basin, are existed, and these enable the comparison between the erosion surfaces and the alluvial surfaces. Approach : 1. Referring to the change of river beds, I have calculated the vertical and horizontal differences comparing the topographic map published in 1916 with that published in 1966 and through the field work 2. In classifying the landform, I have applied the method of micro morphological classification in accordance with the synthetic index based upon the land conditions, and furthermore used the classification method comparing the topographic map published in 1916 and in that of 1966. 3. I have accorded this classification with the classification by mapping through appliying the method of classification in the development history for the field work making the component materials as the available data. 4. I have used the component materials, which were picked up form the outcrop of 10 places and bored at 5 places, as the available data. 5. I have referred to Hydrological survey data of the ministry of Construction (since 1916) on the overflow of Han-river, and used geologic map of Seoul metropolitan area. Survey Data, and general map published in 1916 by the Japanese Army Survbey Dept., and map published in 1966 by the Construction Research Laboratory and ROK Army Survey Dept., respectively. Conclusion: 1. Classification of Morphology: I have added the historical consideration for development, making the component materials and fossil as the data, to the typical consideration in accordance with the map of summit level, reliefe and slope distribution. In connection with the erosion surface, I have divided into three classification such as high, medium and low-,level landform surfaces which were classified as high and low level landform surfaces in past. furthermore I have divided the low level landform surface two parts, namely upper-parts(200-300m) and bellow-parts(${\pm}100m$). Accordingly, we can recognize the three-parts of erosion surface including the medium level landform surface (500-600m) in this area. (see table 22). In condition with the alluvial surfaces I have classified as two landform surfaces (old and new) which was regarded as one face in past. Meamwhile, under the premise of land use, the synthetic, micro morphological classification based upon the land condition is as per the draw No. 19-1. This is the quite new method of classification which was at first attempted in this country. 2. I have learned that the change of river was most severe at seeing the river meandering rate from Dangjung-ni to Nanjido. As you seee the table and the vertical and horizontal change of river beds is justly proportionable to the river meandering rate. 3. It can be learned at seeing the analysis of component materials of alluvial deposits that the component from each other by areas, however, in the deposits relationship upper stream, and between upper parts and below parts I couldn't always find out the regular ones. 4. Having earthern vessel, shell bone, fossil charcoal and and seaweeds includen in the component materials such as gravel, clay, sand and silt in Dukso and Songpa deposits area. I have become to attempt the compilation of chronicle as yon see in the table 22. 5. In according to hearing of basemen excavation, the bottom set conglomerate beds of Dukso beds of Dukso-beds is 7m and Songpa-beds is 10m. In according to information of dredger it is approx. 20m in the down stream. 6. Making these two beds as the standard beds, I have compared it to other beds. 7 The coarse sand beds which is covering the clay-beds of Dukso-beds and Nanjidobeds is shown the existence of so-called erosion period which formed the gap among the alluvial deposits of stratum. The former has been proved by the sorting, bedding and roundness which was supplied by the main stream and later by the branch stream, respectively. 8. If the clay-beds of Dukeo-bed and Songpa-bed is called as being transgressive overlap, by the Eustatic movement after glacial age, the bottom set conglomerate beds shall be called as being regressive overlap at the holocene. This has the closest relationship with the basin formation movement of Seoul besides the Eustatic movement. 9. The silt-beds which is the main component of deposits of flood plain, is regarded as being deposited at the Holocene in the comb ceramic and plain pottery ages. This has the closest relationship with the change of river course and river beds.

A Real-time Interactive Shadow Avatar with Facial Emotions (감정 표현이 가능한 실시간 반응형 그림자 아바타)

  • Lim, Yang-Mi;Lee, Jae-Won;Hong, Euy-Seok
    • Journal of Korea Multimedia Society
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    • v.10 no.4
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    • pp.506-515
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    • 2007
  • In this paper, we propose a Real-time Interactive Shadow Avatar(RISA) which can express facial emotions changing as response of user's gestures. The avatar's shape is a virtual Shadow constructed from the real-time sampled picture of user's shape. Several predefined facial animations overlap on the face area of the virtual Shadow, according to the types of hand gestures. We use the background subtraction method to separate the virtual Shadow, and a simplified region-based tracking method is adopted for tracking hand positions and detecting hand gestures. In order to express smooth change of emotions, we use a refined morphing method which uses many more frames in contrast with traditional dynamic emoticons. RISA can be directly applied to the area of interface media arts and we expect the detecting scheme of RISA would be utilized as an alternative media interface for DMB and camera phones which need simple input devices, in the near future.

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Usefulness of pelvic ultrasonography for the diagnosis of central precocious puberty in girls

  • Yu, Jung;Shin, Ha Young;Lee, Sun Hee;Kim, You Sung;Kim, Jae Hyun
    • Clinical and Experimental Pediatrics
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    • v.58 no.8
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    • pp.294-300
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    • 2015
  • Purpose: It is difficult to differentiate between central precocious puberty (CPP) and premature thelarche (PT) in girls. The aim of this study was to investigate the diagnostic usefulness of pelvic ultrasonography to distinguish between CPP and PT in girls with early breast development. Methods: This study included girls with early breast development who visited the clinic between January 2012 and December 2013. Clinical, laboratory, and pelvic ultrasonographic data were evaluated. CPP and PT were confirmed using the gonadotropin-releasing hormone stimulation test. Results: A total of 248 girls aged 7-8 years were included, among whom 186 (75.0%) had CPP and 62 (25.0%) had PT. The uterine length, transverse diameter, fundus, volume, and cross-sectional area were significantly larger in the CPP group (uterine length, $2.45{\pm}0.50cm$ vs. $2.63{\pm}0.49cm$, P=0.015; uterine volume, $0.95{\pm}0.62cm^3$ vs. $1.35{\pm}0.76cm^3$, P<0.001). However, there were no differences in the fundus/cervix ratio and ovarian measurements. In receiver operating characteristic analysis, a uterine volume of at least $1.07cm^3$ was the most predictive parameter for CPP with an area under the curve of 0.670 (95% confidence interval, 0.593-0.747). Conclusion: Uterine measurements by pelvic ultrasonography in girls with early pubertal development were significantly larger in the CPP group. However, the diagnostic value of ultrasonographic parameters was not high because of a considerable overlap of values between the two groups. Therefore, pelvic ultrasonography in combination with clinical and laboratory tests may be useful to distinguish between CPP and PT in girls.

A Study on the Using of Geo-Spatial Information System for Operation and Management of the Underground Facilities (지하시설물의 유지관리를 위한 지형공간정보시스템의 활용에 관한 연구)

  • 신봉호;박영인;엄재구;양승영
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.12 no.1
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    • pp.53-59
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    • 1994
  • The purpose of this paper is to use geo-spatial information system for effective operation and management of the underground facilities. The subject area is selected and collected all of the drawing in order to get the coordinate points(tic), which become the standard of the subject area and that can be gotten by way of practising control surveying from a existing triangulation station spatial information and attribute information are classificated from obtained data. Also, after giving the code in the attribute information to make it data-based, connecting spatial information with the attribute information to overlap layer each other, and compared the positional accuracy of the data. From the results of this study, conclusions are acquired as follows; 1) To construct the Database of the spatial and attribute data, which contain all kinds of drawings in underground structures, the reservation of registers and the details of changes and so on, results in easily referencing, compiling and analyzing the reserved data in system as their own purposes. 2) It is expected that we can effectively operate and manage the situation among the underground facilities so accurately that we may obviate the safety accidents or the damages of life and property.

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