• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.4
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• pp.29-33
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• 2024

Recent advancements in mobile apps have led to continuously increasing memory demands on smartphone systems. Unlike desktops, which use swap functions to backup the entire memory footprint to storage when memory space is exhausted, smartphones terminate apps and lose significant context. This occurs because large-scale I/O operations to flash memory cause severe delays when swap is enabled on smartphones. This paper discusses how efficient memory management can be performed by using eMRAM, which is faster in write operations than flash memory, as the swap area in mobile systems. Considering the characteristics of backup storage (i.e., flash memory for the file system and eMRAM for the swap areas) as well as the reference characteristics of each page, we demonstrate that the proposed memory allocation and reclamation policies can improve the smartphone's I/O performance by an average of 15%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.868-882
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• 2009

In this paper, channel model and wireless link performance analysis for the short-range wireless communication system applications in the terahertz frequency which is currently interested in many countries will be described. In order to realize high data rates above 10 Gbps, the more wide bandwidths will be required than the currently available bandwidths of millimeter-wave frequencies, therefore, the carrier frequencies will be pushed to THz range to obtain larger bandwidths. From the THz atmospheric propagation characteristics based on ITU-R P.676-7, the available bandwidths were calculated to be 68, 48 and 45 GHz at the center frequencies of 220, 300 and 350 GHz, respectively. With these larger bandwidths, it was shown from the simulation that higher data rate above 10 Gbps can be achieved using lower order modulation schemes which have spectral efficiency of below 1. The indoor propagation delay spread characteristics were analyzed using a simplified PDP model with respect to building materials. The RMS delay spread was calculated to be 9.23 ns in a room size of $6\;m(L){\times}5\;m(W){\times}2.5\;m(H)$ for the concrete plaster with TE polarization, which is a similar result of below 10 ns from the Ray-Tracing simulation in the reference paper. The indoor wireless link performance analysis results showed that receiver sensitivity was $-56{\sim}-46\;dBm$ over bandwidth of $5{\sim}50\;GHz$ and antenna gain was calculated to be $26.6{\sim}31.6\;dBi$ at link distance of 10m under the BPSK modulation scheme. The maximum achievable data rates were estimated to be 30, 16 and 12 Gbps at the carrier frequencies of 220, 300 and 350 GHz, respectively, under the A WGN and LOS conditions, where it was assumed that the output power of the transmitter is -15 dBm and link distance of 1 m with BER of $10^{-12}$. If the output power of transmitter is increased, the more higher data rate can be achieved than the above results.

• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.107-123
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• 2020

With stabilization of the recent multi-GNSS infrastructure, and as multi-GNSS has been proven to be effective in improving the accuracy of the positioning performance in various industrial sectors. In this study, in view that SF(Single frequency) GNSS receivers are widely used due to the low costs, evaluate effectiveness of SF Real Time Point Positioning(SF-RT-PP) based on four multi-GNSS surveying methods with RTCM-SSR correction streams in static and kinematic modes, and also derive response challenges. Results of applying SSR correction streams, CNES presented good results compared to other SSR streams in 2D coordinate. Looking at the results of the SF-RT-PP surveying using SF signals from multi-GNSS, were able to identify the common cause of large deviations in the altitude components, as well as confirm the importance of signal bias correction according to combinations of different types of satellite signals and ionospheric delay compensation algorithm using undifferenced and uncombined observations. In addition, confirmed that the improvement of the infrastructure of Multi-GNSS allows SF-RT-SPP surveying with only one of the four GNSS satellites. In particular, in the case of code-based SF-RT-SPP measurements using SF signals from GPS satellites only, the difference in the application effect between broadcast ephemeris and SSR correction for satellite orbits/clocks was small, but in the case of ionospheric delay compensation, the use of SBAS correction information provided more than twice the accuracy compared to result of the Klobuchar model. With GPS and GLONASS, both the BDS and GALILEO constellations will be fully deployed in the end of 2020, and the greater benefits from the multi-GNSS integration can be expected. Specially, If RT-ionospheric correction services reflecting regional characteristics and SSR correction information reflecting atmospheric characteristics are carried out in real-time, expected that the utilization of SF-RT-PPP survey technology by multi-GNSS and various demands will be created in various industrial sectors.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.116-124
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• 2006

Remarkable winter season warming has been observed in East Asian countries during the last century. Accordingly, significant effects on dormancy and the resulting budburst of deciduous trees are expected. However phenological observations are rare and insufficient compared with the long-time climate records in the same region. A chill-day accumulation, which can be estimated from daily maximum and minimum temperature, is expected to make a reasonable proxy for dormancy depth of temperate zone fruit trees. To simulate dormancy depth during 1921-2004, a chill-day model parameterized for 'Campbell Early' grapevine, which is the major cultivar grown virtually anywhere in South Korea, was applied to daily temperature data at 8 locations in South Korea. The calculations showed that the chilling requirement for breaking endo-dormancy of this grapevine cultivar can be satisfied by mid-January to late February in South Korea, and the date was delayed going either northward or southward from the 'Daegu-Jeonju' line crossing the middle of South Korea in the east-west direction. Maximum length of the cold tolerant period (the number of days between endo-dormancy release and forced dormancy release) showed the same spatial pattern. When we divide the 83 years into 3 periods (I: 1921-1950, II: 1951-1980, and III: 1981-2004) and get the average of each period, dormancy release date of period III was accelerated by as much as 15 days compared with that of period I at all locations except Jeju (located in the southernmost island with subtropical climate) where an average15-day delay was predicted. The cold- tolerant period was also shortened at 6 out of 8 locations. As a result, budburst of 'Campbell Early' in spring was accelerated by 6 to 10 days at most locations, while inter-annual variation in budburst dates was increased at all locations. The earlier budburst after the 1970s was due to (1) warming in winter resulting in earlier dormancy release (Incheon, Mokpo, Gangneung, and Jeonju), (2) warming in early spring accelerating regrowth after breaking dormancy (Busan and Jeju), and (3) both of them (Seoul and Daegu).

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.3
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• pp.75-88
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• 2009

This paper presents a video quality assessment method based on quality degradation factors of real-time multimedia streaming services. The video quality degradation is caused by video source compression and network states. In this paper, we propose a blocky metric on an image domain to measure quality degradation by video compression. In this paper, the proposed boundary strength index for the blocky metric is defined by ratio of the variation of two pixel values adjacent to $8{\times}8$ block boundary and the average variation at several pixels adjacent to the two boundary pixels. On the other hand, unnatural image movement caused by network performance deterioration such as jitter and delay factors can be observed. In this paper, a temporal-Jerkiness measurement method is proposed by computing statistics of luminance differences between consecutive frames and play-time intervals between frames. The proposed final Perceptual Video Quality Metric (PVQM) is proposed by consolidating both blocking strength and temporal-jerkiness. To evaluate performance of the proposed algorithm, the accuracy of the proposed algorithm is compared with Difference of Mean Opinion Score (DMOS) based on human visual system.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.12
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• pp.1381-1389
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• 2003

컴퓨터와 첨단영상매체의 발달로 디자인 분야에서도 컴퓨터를 사용하여 색을 자유롭게 선택할 수 있는 그래픽 소프트웨어가 도입되고 있으나 영상정보의 색채 재현성과 영상입출력 장치의 다양화로 인한 색채 불일치에 대한 문제들이 극복해야할 시급한 과제로 부각되고 있다. 따라서, 색채 영상정보 입출력장치의 색채구현 성능과 인간의 색채인지 원리이론을 바탕으로 색보정 알고리즘이 발전하여 색보정 엔진의 개발이 국제적으로 활발히 진행되고 있는 연구 분야임에도 불구하고 국내에서는 그 연구사례가 상대적으로 극히 미비한 실정이며, 더욱이, CAD 시스템을 이용한 패션/텍스타일 디자인 분야에서는 이에 대한 연구가 거의 이루어지지 않고 있다. 본 연구에서는 염색 직물의 색을 CAD시스템을 이용하여 soft-copy로 재현하고 이것을 다시 hard-copy로 출력하여 물리적 측정치와 주관적 색채 인지도간의 일치도를 비교하고, 물리적, 주관적 색차의 한계치를 제시함으로써, 패션/텍스타일 디자인 CAD시스템 운용에 기초가 되는 자료를 제공하려 하였다. 연구의 절차는 객관적 측정과 주관적 평가 두 단계로 나누어 진행되었다 연구에 사용된 직물은 7가지 색상의 면 염직물로써, CAD시스템을 이용하여 각 직물당 5개의 soft-copy를 재현하고, 이것을 다시 hard-copy로 출력하여 spectrophotometer를 이용해 물리적 측정(ΔE, ΔL, Δc, Δh)을 실시하였다. 또한 주관적 평가에는 20명의 의류학 전공 학생들이 참여하였다. 결과 분석에는 분산분석과 Friedman분석이 사용되었다. 연구 결과 색차 측정에 대한 물리적 측정치와 1차 주관적 평가치 사이의 일치도는 90.5%로 나타났으며, 2차 주관적 평가치와의 rank order는 거의 일치하는 것으로 나타났다. 또한 주관적 평가에서 피험자들은 색차인지에 있어 CIELAB 색채공간의 각각의 색요소 차이보다는 전체 색차에 더 영향을 받는 것으로 나타났다.녹색콩풍뎅이의 유충에 의하여 피해를 받는 것이 확인되었다. 녹색콩풍뎅이 유충의 피해를 받은 금잔디는 황화되거나 시들음 증상이 있었고, 이듬해 봄에는 잔디의 회복이 지연되었다.ic conductivity. The changes of $varepsilon$′ and $varepsilon$" were well estimated with this modified Havriliak-Negami model.05). 상기의 결과를 토대로, 성장과 전어체내 지방산조성에 있어서 뱀장어 치어의 사료내 EPA와 DHA의 첨가효과 미약한 것으로 판단되며, 사료내 LNA (n-3)와 LA(n-6) HUFA을 각각 0.35%, 0.65% 첨가했을 때 WG, SGR, FE, PER이 가장 높았으나, 이전의 실험(Takeuchi, 1980)과 동일한 수준인 n-3와 n-6를 각각 0.5%씩 첨가한 실험구와는 유의적인 차이를 보이지 않았다. 이렇게 볼 때, 뱀장어 치어의 필수지방산은 LNA (n-3), LA (n-6)이고, 그 적정수준은 각각 0.35-0.5%, 0.5-0.65%임을 보여준다.George W, Bush)가 새로운 지도자로 취임하여 얼마 되지 않은 2001년 9월 11일 사상 초유로 본토에서 알 카에다 테러리스트 조직에 의해 공격받게 되었다. 뉴욕의 세계무역센터 빌딩 2개가 완전히 붕괴되고, 펜타곤에 민간 여객기가 충돌하여 많은 사람이 살상 당하고, 전체적으로 세계 80여 개국으로부터의 6천여 명이 살상되었다. 전 세계와 미국은 국제 테러리스트들의 야만적 행위에 대해 경악하고 이제 미국은 그 대외정책의 최우선순위를 국제 테러를 발본색원하는 것에 두게 되었다. 본 논문은 1998년 한국에서 새로이 출범한 김대중 행정부가 북한에 대해 실시한 포용정책이 어떠한 성과를 거두고 어떠한 문제점을 간과하고 있는가에 대해 논의하고, 대북 정책의 새로운 지평을 논의하는 것을 목적으로 하고

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.3
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• pp.96-106
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• 2009

Extending the scale of the distributed processing in a single Ethernet cluster is physically restricted by maximum ports per switch. This paper presents an implementation of MPI-based multicluster consisting of multiple Ethernet switches for extending the scale of distributed processing, and a asymptotical analysis for communication overhead through execution-time analysis model. To determine an optimum task partitioning, we analyzed the processing time for various partitioning schemes, and AAP(accumulator array partitioning) scheme was finally chosen to minimize the overall communication overhead. The scope of data partitioned in AAP was modified to fit for incremented nodes, and suitable load balancing algorithm was implemented. We tried to alleviate the communication overhead through exploiting the pipelined broadcast and flat-tree based result gathering, and overlapping of the communication and the computation time. We used the linear pipeline broadcast to reduce the communication overhead in intercluster which is interconnected by a single link. Experimental results shows nearly linear speedup by the proposed parallel distributed GHT implemented on MPI-based Ethernet multicluster with four 100Mbps Ethernet switches and up to 128 nodes of Pentium PC.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.235-242
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• 2017

Marsupialization and decompression constitute a well-established procedure for treating cavitary bone lesions of the jaw. The technique can be a primary treatment option, especially for pediatric patients with large cysts or lesions involving vital anatomical structures, such as a developing tooth germ. In this procedure, a decompression stent, such as a customized acrylic obturator or space-maintaining appliance, silicone tube, or nasal cannula, is inserted to maintain the patency of the cyst. However, this may cause clinical problems, such as irritation or trauma to the adjacent tissues, as well as discomfort to the patient, or failure of the stent due to cyst shrinkage. It can also be a reason for patient noncompliance. In the cases described here, a minimally invasive marsupialization technique using a metal tube made from a 16-gauge needle was used for odontogenic cysts in pediatric patients associated with unerupted teeth. Through this method, the lesions were removed, with patient cooperation, and the cyst-associated teeth erupted spontaneously.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.1
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• pp.42-56
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• 2002

It is possible but not efficient to model and simulate asynchronous microprocessors with the existing HDLs(HARDware Description Languages) such as VHDL or Verilog. The reason it that the description becomes too complex. and also the simulation time becomes too long to explore the design space. Therefore it is necessary to establish a methodology and develop a tool for modeling the handshake protocol of asynchronous microprocessors very easily and simulating it very fast. Under this objective an efficient CAD(Computer Aided Design) tool SLEDS(System Level Event-Driven Simulator) was developed which can evaluate performance of a processor through modeling with a simple description an simulating with event driven engine in the system level. The ultimate goal in the tool SLEDS is to fin the optimal conditions for a system to produce high performance by balancing the delay of each module in the system. Besides SLEDS aims at verifying the design through comparing the expected results with the actual ones by performing the defined behavior.

• Proceedings of the Korean System Dynamics Society
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• 2004.08a
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• pp.87-107
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• 2004

우리나라에 이동통신이 처음 소개된 이래로 눈부신 발전을 거듭하여 왔으며, 급기야. 무선통신 서비스를 중심으로 새로운 성장력과 패러다임 전환의 가능성에 대한 전망을 논할 수 있는 수준이 되었다. 이러한 추세에 맞추어 휴대인터넷 시장에 대한 연구가 활발히 진행되고 있으며 국민경제적 효과변화나 시장 경쟁환경의 변화에 가장 영향을 미칠 수 있는 요인들 중, 사업자 수를 어떻게 선정할 것인가에 대해 다양한 접근이 시도되고 있다. 기존의 연구들은 휴대인터넷 시장을 분석하는데 있어 시장규모가 일방향으로 사업자 수에 영향을 미친다는 측면에서 이루어지고 있으며, 대부분 휴대인터넷 시장을 단일시장으로 범위를 한정하고 성장중인 시장을 정적으로 가정하여 시장성장 추이 분석 등에 주안점을 두는 단편적 연구가 수행되어져 왔다. 휴대인터넷 시장의 단편적 분석이 아닌 '모바일인터넷' , '초고속유선인터넷', '무선인터넷', '휴대인터넷' 등 네 가지 영역을 동시에 고려함으로써 영역간 복잡성과 동적인 관계 속에서 시장이 성장해 나아간다는 가정을 바탕으로, 시장에 내재되어 있는 관련요소간 상호영향과 신규정책 및 제도적 변화 수용에 있어 발생하는 시간적 공간적 지연 등을 고려한 동태적 분석을 수행하였다. 연구를 수행하기 위해 다양한 변수간의 인과관계, 피드백 구조와 시간흐름에 따른 시스템의 변화를 파악하는데 매우 유용한 도구인 시스템다이내믹스 기법을 활용하여 휴대 인터넷 시장의 동적인 구조를 알아보고 사업자 선정정책의 시행을 앞두고 있는 현재시점에서 의미있는 시사점을 제공하였다.시하고자 한다.채취하여 임신진단키트(제네디아프로테 트, 녹십자)를 이용하여 임신여부를 1차적으로 확인하였다. 과배란을 유기한 13두의 공란우중 9두(69.2%)가 과배란 반응을 나타내었으며, 회수된 수정란 51개중 이식가능수정란은 38개(74.5%) 였다. 발정동기화를 유도한 수란우 40두중에서 35두(87.5%)가 발정이 동기화되었으며, 그 중 황체검사를 통하여 30두의 수란우에 수정란을 이식하였다. 수정란이식후 13일(발정주기 21일)에 혈액을 이용한 임신진단에서 농가별 수태율은 각각 37.5%, 70.0%, 60.0% 및 71.4% 로서 평균 60.0%를 나타내었다.서 39$^{\circ}C$, 5% $CO_2$ 배양기에 48시간 배양하면서 생존여부를 판단하였다. 실험 2에서 확장배반포배 수정란이 25.3%의 생존율을 나타내었으며, 실험 1과 실험 3에서는 수정란의 형태와 관계없이 생존성을 확인할 수 없었다. 이상의 결과로 보아 glycerol 완만동결에서는 확장배반포기 수정란 이상이 보존가능한 것으로 추정되나 더 추가적인 연구가 요구된다.c kinase 활성의 변동은 정소 내 간충조직, 세정관 상피의 증식 및 기능적 분화 과정을 매개하는 생리적 활성분자 수용체 하위의 신호전달 과정에 Src-Csk loop에 의한 조절가능성을 확인할 수 있었다.rugrene의 향기성분이 주요 성분군으로 확인되었다. 2. 생강나무에서 생강의 향기를 발산하는 성분으로는 $\beta$-myrcene, o-terpinolene, phellandrone, ι-limonene, $\b