• Title/Summary/Keyword: 조절용이성

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Low Loss LTCC Materials in mm Wavelength Region with Use of Common Glass (공통 글라스를 이용한 mm 대역용 저손실 LTCC 소재)

  • Lee, Sung-Il;Yeo, Dong-Hun;Park, Zee-Hoon;Shin, Hyo-Soon;Hong, Youn-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.330-330
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    • 2010
  • 이동통신 시스템의 소형화, 경량화, 다기능화 추세에 따라 이동통신 부품도 단위 부피당 소자의 집적도를 증가시키기 위하여 고집적화 추세로 급진전되고 있다. 이에 따라 세라믹 공정 기술도 고집적 추세로 다층화 되고 있어 수동소자의 내장화에 대한 필요성이 증대되고 있다. 이를 위하여 다양한 유전율 대역의 이종소재간 접합을 시도하지만 de-lamination, 내부 crack 등의 결함들이 발생하므로 열팽창계수 조절이 용이한 동종의 글라스를 사용하는 것이 유용하다. 본 연구에서는 공통의 글라스를 개발한 후 다양한 필러들을 혼합하여 mm파 대역에서 다양한 유전율을 갖는 LTCC 소재를 개발함으로써, 수동소자의 내장화에 따른 이종접합시의 매칭성을 극대화하고자 하였다. 이를 위하여 CaO-$Al_2O_3-SiO_2-B_2O_3$계 공통글라스에 $CaZrO_3$, $1.3MgTiO_3$, $2La_2O_3TiO_2$ 필러를 혼합하여 소결체의 미세구조, 유전특성 및 열기계적 특성을 고찰하였다. 이때 유전율 6에서 20에 이르는 저손실 소재를 개발할 수 있었다.

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Low-computation Motion Tracker Unit Linkable to Video Codec for Object Tracking Camera (동영상 코덱과 연동이 가능한 객체 추적 카메라용 저연산량 움직임 추적기)

  • Yang, Hyeon-Cheol;Lee, Seong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.10
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    • pp.66-74
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    • 2008
  • Surveillance system using active tracking camera has no distance limitation of surveillance range compared to supersonic or sound sensors. However, complex motion tracking algorithm requires huge amount of computation. Compared to conventional methods using DSPs or embedded processors, this paper proposes and implements a novel motion tracker unit that detects and extracts motion information of moving objects by using picture difference of consecutive frames. The proposed motion tracker unit was implemented in FPGA with about 13,000 gates. It processes NTSC format video and was verified by embedding it into the active surveillance camera system. We also propose and implements a motion estimator unit linkable to video codec by embedding the proposed motion tracker unit into ready-made motion estimator unit. The implemented motion estimator unit is about 17,000 gates in $0.35{\mu}m$ process.

Effects of Social Commerce Attributes on the Trust, Flow and Loyalty (소셜커머스 속성이 신뢰, 몰입과 충성도에 미치는 영향)

  • Sun, Zeng-Jun;Mun, Young-Ju;Lee, Jong-Ho
    • The Journal of the Korea Contents Association
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    • v.12 no.2
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    • pp.265-275
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    • 2012
  • This study is based on the results from the previous one. It proved that reputation, price and ease of use, entertainment are the major attributes of social commerce. Research model and hypotheses by using the trust and flow as mediator, loyalty is the dependent variable and the items as moderator. The results were as follows: First, reputation and price have positive effects on trust. Second, all attributes of social commerce have positive effect on flow, except for the ease of use. Third, the trust has positive effect on flow. Fourth, the trust and flow has positive effect on loyalty. The last, the attributes of social commerce have significant difference in trust and flow according to different products. The results of this study presented the strategic implications for operators at social commerce area.

Energy Efficient Transmission Parameters Analysis of TDMA Based HR-WPAN System for Ship Environment (선박환경에서 에너지 효율성을 고려한 TDMA기반 고속 WPAN시스템의 전송파라미터 분석)

  • Park, Young-Min;Lee, Woo-Young;Lee, Seong-Ro;Lee, Yeon-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.9A
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    • pp.712-718
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    • 2009
  • This paper proposes the optimal transmission parameter selection method for an energy efficient Wireless Personal Area Network (WPAN) system which is applicable to the Maritime Telematics targeting for various ship models. Since the transmission parameter selection is an important factor for WPAN system to decide its energy efficiency, we propose an energy consumption model for ship area network (SAN) employing IEEE 802.15.3 based TDMA HR-WPAN model and analyzes the effect of transmission parameter selection on the performance of energy consumption. In particular, the main performance decision parameter of the SAN applying HR-WPAN is path loss, since it is very varied according to the material of shipbuilding such as steel (large ship), FRP (medium size ship) and compound wood (small ship). Thus, we analyzed and demonstrated that the proper transmission parameter selection among transmit power, PHY data rate and fragment size for each ship model guarantee the energy efficiency.

A Study of Wear Behavior for Sealing Graphite at Elevated Temperature (씰링 그라파이트의 고온 마모 거동에 관한 연구)

  • Kim, Yeonwook;Kim, Jaehoon;Yang, Hoyoung;Park, Sunghan;Lee, Hwankyu;Kim, Bumkeun;Lee, Seungbum;Kwak, Jaesu
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.5
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    • pp.113-120
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    • 2013
  • Graphite is commonly used as a solid lubricant leading to low friction coefficient and abrasion. In this study, wear behavior of sealing graphite(HK-6) at elevated temperature was evaluated. Reciprocating wear test was carried out as wear occurred graphite as a seal(HK-6) is positioned between the liner and driving shaft. Variables which are temperature, sliding speed and contact load are set. This study suggest optimized environment conditions through the wear properties of graphite.

STUDIES ON THE PLANT GROWTH REGULATING EFFECT OF PHTHALAMIC ACID AND ITS DERIVATIVES (Phthalamic acid 및 이의 유도체의 식물생장조정작용에 미치는 영향에 관한 연구)

  • Lee Sung Hwan;Do Un Hoi
    • Korean journal of applied entomology
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    • v.8
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    • pp.11-18
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    • 1969
  • 식물 생장 조절제로서 phthalamic acid와 그 유도체를 사용하여 추락답을 개량하기 위한 예비 시험을 실시하여 다음과 같을 결과를 얻었다. 1) 아래 7종의 phthalamic acid 및 그 유도체를 합성 또는 정제하여 공시약제로 하였으며 합성품의 수율은 $87-92\%$였다. (표 1) A. Phthalamic acid B. Phthalanilic acid C. N- (o-Chlorophenly)-phthalamic acid D. N-(p-Chlorophenyl)-phthalamic acid E. N- (3,4-Dichlorophenyl)-phthalamic acid F. Sodium-N- (m-tolyl)-phthalamate (Duraset) G. Sodium-N-(1-naphthyl)-phthalamate (Alanap) 2) Wheat straight growth test에서 공시약제는 10ppm 및 20ppm의 농도에서 Control보다 월등한 생장 촉진효과를 보였으며 특히 흥미있는 것은 phthalamic acid 유도체가 phthalamic acid 자체보다 더 좋은 효과를 보였다. (표4, 그림 1) 3) 수도 종자의 발아 시험 결과 초장은 phthalamic acid 유도체가 적시 phthalamic acid 자체보다 좋았으며 기중 Alanap. 3,4-dichlorophenyl phthalamic acid 및 Duraset가 가장 좋았으나 10-100ppm 범위내의 농도에 거의 영향없었다. (표 5) 근의 생육은 일반적으로 약제의 종류에 따라 상이할 뿐 아니라 초장의 생육보다 더욱 약제에 민감하였다. 근장은 phthalamic acid, phthalanilic acid, (p-chlorophenyl)phthalamic acid, 3,4-dichlorophenyl phthalamic acid가 Control 보다 약간 좋은 효과를 보였고, Alanap은 매우 불량하였다. (표 6) 근수는 (p-chlorohhenyl) phthalamic acid만 Control에 비해 우수하였고 나머지 약제는 대체로 근수를 감소시키거나 Control과 비슷한 효과를 보였다. (표 7) 또한 농도가 증가함에 따라 근수는 감소하였으며, Alanap, (o-chlorophenyl) phthalamic acid는 근단에 심한 약해가 일어났다. 4) 전근시험에서 근수는 공시약제에 의하여 증가되었으나 50-200ppm의 농도에서 별 영향이 없었다.(표 8, 그림 2) 근장은 농도가 증가함에 따라 감소되는 영향이었으나 공시약제에는 상이한 효과를 보였다. 5) 이상 결과에서 p-chlorophenyl phthalamic acid 및 3,4-dichlorophenyl phthalamic acid가 수도용 식물생장조절제로서 실용적 개발의 가능성을 보였다.

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Energy Efficient Transmission Parameters Analysis of TDMA based HR-WPAN System for Ship Environment (선박환경에서 에너지 효율성을 고려한 TDMA기반 고속 WPAN시스템의 전송파라미터 분석)

  • Park, Young-Min;Lee, Woo-Young;Lee, Seong-Ro;Lee, Yeon-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.10A
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    • pp.769-775
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    • 2009
  • This paper proposes the optimal transmission parameter selection method for an energy efficient Wireless Personal Area Network (WPAN) system which is applicable to the Maritime Telematics targeting for various ship models. Since the transmission parameter selection is an important factor for WPAN system to decide its energy efficiency, we propose an energy consumption model for ship area network (SAN) employing IEEE 802.15.3 based TDMA HR-WPAN model and analyzes the effect of transmission parameter selection on the performance of energy consumption. In particular, the main performance decision parameter of the SAN applying HR-WPAN is path loss, since it is very varied according to the material of shipbuilding such as steel (large ship), FRP (medium size ship) and compound wood (small ship). Thus, we analyzed and demonstrated that the proper transmission parameter selection among transmit power, PHY data rate and fragment size for each ship model guarantee the energy efficiency.

A Study for Application of Polycarboxilic Type Admixture to Precast High-Strength Concrete Piles (프리캐스트 고강도 콘크리트(PHC) 파일에 조강형 폴리카본산(PC)계 혼화제의 적용에 관한 연구)

  • Yi, Seong Tae;Noh, Jae Ho;Park, Chul Ju;Heo, Hyung Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.1
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    • pp.263-270
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    • 2011
  • In this study, the performance of Poly-Naphthalene Sulfonate (PNS) type-admixture used widely in South Korea and Polycarboxilic type-admixture(i.e., WF2000) developed in the J company of the domestic, for precast concrete products produced in the factories, was evaluated. With the 20% reduced usage of WF2000 compared to PNS type-admixture, workability was considerably improved due to high water-reducing ratio, accelerating effect of concrete setting and accelerant dispersant action, which the product has, under the high temperature. In addition, the development of initial and long-term strengths of PHC plies was predominant. For WF2000, it is also possible to correspond with the change of original materials and environmental conditions since the control of water-reducing and supporting forces is feasible. Accordingly, it was noted that WF2000 is superior for deterioration of production & workability and bad casting problems in summer and the solution of initial strength reduction problem due to the delay of setting in winter.

Analysis of Flood Control Capacity of Agricultural Reservoir Based on SSP Climate Change Scenario (SSP 기후변화 시나리오에 따른 농업용 저수지 홍수조절능력 분석)

  • Kim, Jihye;Kwak, Jihye;Hwang, Soonho;Jun, Sang Min;Lee, Sunghack;Lee, Jae Nam;Kang, Moon Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.63 no.5
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    • pp.49-62
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    • 2021
  • The objective of this study was to evaluate the flood control capacity of the agricultural reservoir based on state-of-the-art climate change scenario - SSP (Shared Socioeconomic Pathways). 18 agricultural reservoirs were selected as the study sites, and future rainfall data based on SSP scenario provided by CMIP6 (Coupled Model Intercomparison Project 6) was applied to analyze the impact of climate change. The frequency analysis module, the rainfall-runoff module, the reservoir operation module, and their linkage system were built and applied to simulate probable rainfall, maximum inflow, maximum outflow, and maximum water level of the reservoirs. And the maximum values were compared with the design values, such as design flood of reservoirs, design flood of direct downstream, and top of dam elevation, respectively. According to whether or not the maximum values exceed each design value, cases were divided into eight categories; I-O-H, I-O, I-H, I, O-H, O, H, X. Probable rainfall (200-yr frequency, 12-h duration) for observed data (1973~2020) was a maximum of 445.2 mm and increased to 619.1~1,359.7 mm in the future (2011~2100). For the present, 61.1% of the reservoirs corresponded to I-O, which means the reservoirs have sufficient capacity to discharge large inflow; however, there is a risk of overflowing downstream due to excessive outflow. For the future, six reservoirs (Idong, Baekgok, Yedang, Tapjung, Naju, Jangsung) were changed from I-O to I-O-H, which means inflow increases beyond the discharge capacity due to climate change, and there is a risk of collapse due to dam overflow.

Evaluation of Noise Reduction Performance of HVAC System for Ships (선박용 HVAC 시스템의 소음저감성능 평가)

  • Kim, Sang-Ryul;kim, Hyun-Sil;Kim, Jae-Seung;Kim, Bong-Ki;Lee, Sung-Hyun
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.8
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    • pp.497-503
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    • 2010
  • In this paper, evaluation of noise reduction performance of HVAC system for ships by means of HVAC mock-up system is presented. Test is done for six different types of HVAC elements including room unit, silencer, etc. It is found that when diameter of silencer is small and air flow is large, flow noise degrades insertion loss. However, as diameter of silencer becomes larger, the effect of flow noise becomes smaller, and insertion loss up to 25 dB is measured. It is observed that insertion loss of diffuser type room unit is usually between zero and 10 dB, whereas that of the nozzle type room unit can be down to - 15 dB. In addition, it is shown that changing duct arrangement can reduce cabin noise by up to 2 dB, and providing same air flow to each room unit is crucial for generating less noise.