• Title/Summary/Keyword: STD

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A Comparative Study on the Anthropometric Method - Anthropometric Point and Line - (인체측정(人體測定) 방법(方法)에 관(關)한 비교(比較) 연구(硏究) - 인체측정(人體測定) 기준점(基準點), 기준선(基準線)을 중심(中心)으로 -)

  • Kwon, Young-Ja;Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.5 no.4
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    • pp.89-100
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    • 2001
  • The major purpose of this study is to show exact and convenient devices and minimize error in body measurement. This study was referred to 13 records and compared 6 items that the investigator's opinion has been differed about anthropometric point and line and suggested convenient and radical device, and measured by if need be. The 30 students from 20 to 25 ages were measured and data was analyzed by mean, std. deviation and paired t-test. The results are as follows. 1. Side neck point has been suggested many devices, but was suggested in this study to decide by M. trapezius, cervicale point and fossa jugularis point. 2. Shoulder point was suggested to decide by point of 1/2 armhole depth, upper arm depth and shoulder depth except acromion point. 3. Waist circumference line has been differed between horizontal line and natural line. The result of measurements was no significant difference between two methods and natural line was convenience. Waist circumference line must considered two methods together for garment construction and somato type. 4. The standard of hip circumference line has been differed between buttock point and trochanterion point. The result of measurements was significant difference between two methods, but two point must considered together because of body type. 5. Chest circumference line at scye has been differed between horizontal line and natural line. The result of measurements was significant difference between two methods and natural line was convenience. Chest circumference line at scye must studied to decide method the line for garment construction.

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Study on the Optimum Harvest Timing for Different Operational Systems of Rice (벼의 수확작업 체계별 수확정기 결정에 관한 연구)

  • 이종호;강화석;정창주
    • Journal of Biosystems Engineering
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    • v.3 no.2
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    • pp.88-99
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    • 1978
  • In this study, rice harvesting systems suitable to Korean situations and the optimum timing of these systems were determined, respectively, based on experimentally determined factors such as filed yield and the milling quantity and quality measured at various levels of the grain moisture content at harvest. Rice varieties used for the experiment were the AKIBARE (Japonica-type) and the SUWEON 251 (high yielding TONGIL sister-line variety), The harvesting systems studied by the experimental work of this study were traditional system with both the wet material and dry-material threshing system by use of binder with both the dry-material and wet-material threshings, and system by use of combine. Grain samples were taken from final products of the paddy rice harvested from the experiment a fields for each system to measure the recovery rates of the milled rice. The results may be summarized as follows; 1. The milling recovery rate of the AKIBARE variety had highest value within the range of the grain moisture at harvest, showing from 21 to 26 percent. The head-rice recovery for the same variety was a little greater in the wet-material threshing than in the dry-material threshing , higher values of which , were 20 to 25 percent , seen within the range of grain moisture at harvest regardless of the harvesting systems tested. 2. The milling recovery of the SUWEON 251 , when tested for different harvesting systems and harvesting grain moisture, did not show a statistically significant different. In contrast , head-rice recovery for the systems operated by the wet-material threshing was much greater than that by the -material threshing. The difference of the recoveries between these systems range from 2.6 to 4.7 percent. 3. An assessment of the optimum period of -harvest timing for each of the harve\ulcornersting systems tested were made bJ.sed on (a) the maximum total milled-rise yield and (b) the percentage reduction in the total milled-rice yield due to untimely harvest operations. The optimum period determined are: 23-19% for the ATD, AC, STD, SBW, STW systems, 25-21% for the ATW ani ABW systems, and 27-18% for the ABD, SBD, and SC systems, respectively.

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The Characteristics Analysis of Track of Laser Metal Deposition Using AISI M2 Powder (AISI M2 파우더를 이용한 레이저 메탈 디포지션의 트랙 특성 분석)

  • Kim, WonHyuck;Song, MyungHwan;Park, InDuck;Kang, DaeMin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.4
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    • pp.463-470
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    • 2016
  • In this paper, the characteristics analysis of LMD track, such as including track structure, track wear resistance and track thickness, were analyzed to enhance the deposition efficiency using a diode-pumped disk laser. SKD61 hot work steel plate and Fe based AISI M2 alloy were used as a the substrate and powder for the LMD process, respectively. The laser power, track pitch and powder feed rate among LMD parameters were adopted to estimate the deposition efficiency. As the laser power is increased, heat input and melting pool on the substrate is grown also increases, so resulting in the increased LMD track thickness was increased. Through EPMA mapping analysis of the cross-section in the LMD track, it was observed that all the elements are evenly distributed inside. Therefore, the entire hardness in the LMD track is expected to be almost uniform regardless of location. The characteristics of the LMD specimen were excellent compared to the STD11 specimen in terms of the wear track width and the wear rate as well as the coefficient of friction. Especially the wear rate of LMD specimen has been significantly reduced by 60 % or more. From Based on the experimental results, the prediction formula of LMD thickness was calculated by using laser power, track pitch and powder feed rate.

A Study of a Changing of Physical and Chemical Intra-structure on Si-DLC Film during Tribological Test (실리콘 함유 DLC 박막의 마찰마모 시험에 의한 물리적 특성 및 화학적 결합 구조 변화 고찰)

  • Kim, Sang-Gweon;Lee, Jae-Hoon;Kim, Sung-Wan
    • Journal of the Korean Society for Heat Treatment
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    • v.24 no.3
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    • pp.127-132
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    • 2011
  • The silicon-containing Diamond-like Carbon (Si-DLC) film as an low friction coefficient coating has especially treated a different silicon content by plasma-enhanced chemical vapor deposition (PECVD) process at $500^{\circ}C$ on nitrided-STD 11 mold steel with (TMS) gas flow rate. The effects of variable silicon content on the Si-DLC films were tested with relative humidity of 5, 30 and 85% using a ball-on-disk tribometer. The wear-tested and original surface of Si-DLC films were analysed for an understanding of physical and chemical characterization, including a changing structure, via Raman spectra and nano hardness test. The results of Raman spectra have inferred a changing intra-structure from dangling bonds. And high silicon containing DLC films have shown increasing carbon peak ratio ($I_D/I_G$) values and G-peak values. In particular, the tribological tested surface of Si-DLC was shown the increasing hardness value in proportional to TMS gas flow rate. Therefore, at same time, the structure of the Si-DLC film was changed to a different intra-structure and increased hardness film with mechanical shear force and chemical reaction.

Electromagnetic Pulse Shielding Effectiveness and Construction Availability of Cast-In-Place Structures Using Corrugated Metal-Plates

  • Kim, Suk Bong;Yoon, Sangho;Min, Gyung Chan;Ahn, Sungjin;Park, Young Jun
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.1
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    • pp.84-89
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    • 2013
  • This study aims to examine the effectiveness of electromagnetic pulse shielding in cast-in-place protective shelters using corrugated metal-plates, and then reviews their usability for the Republic of Korea Army. The Korea Corps of Engineering has evaluated corrugated metal-plates as a construction material for cast-in-place structures, which have to defend against mechanical impacts as well as electromagnetic pulses. Corrugated metal-plate is known as a superb mechanical protective material, so much so that it has been employed in ammunition magazines and artillery platforms in the armed forces. Moreover, as a metal, such as steel and copper, it is universally recognized as one of the most effective electromagnetic pulse shielding materials. In addition to effectively shielding from electromagnetic pulses and protecting against mechanical impacts, corrugated metal-plates should prove to be an appropriate construction material for the cast-in-place protective shelter in terms of construction availability and economic feasibility. The shielding effectiveness of the suggested structures is examined based on MIL-STD 188-125-1. A few frequency bands need an increase of 15~30dB in shielding effectiveness because of unbidden apertures caused by flaws associated with welding, assembling, and material deformation. However, allowing for the approximately 40dB of shielding provided by soil; the examined structure, which is buried underground, can offset its shortcomings sufficiently.

VLSI architecture design of CAVLC entropy encoder/decoder for H.264/AVC (H.264/AVC를 위한 CAVLC 엔트로피 부/복호화기의 VLSI 설계)

  • Lee Dae-joon;Jeong Yong-jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.5C
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    • pp.371-381
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    • 2005
  • In this paper, we propose an advanced hardware architecture for the CAVLC entropy encoder/decoder engine for real time video compression. The CAVLC (Context-based Adaptive Variable Length Coding) is a lossless compression method in H.264/AVC and it has high compression efficiency but has computational complexity. The reference memory size is optimized using partitioned storing method and memory reuse method which are based on partiality of memory referencing. We choose the hardware architecture which has the most suitable one in several encoder/decoder architectures for the mobile devices and improve its performance using parallel processing. The proposed architecture has been verified by ARM-interfaced emulation board using Altera Excalibur and also synthesized on Samsung 0.18 um CMOS technology. The synthesis result shows that the encoder can process about 300 CIF frames/s at 150MHz and the decoder can process about 250 CIF frames/s at 140Mhz. The hardware architectures are being used as core modules when implementing a complete H.264/AVC video encoder/decoder chip for real-time multimedia application.

Improved RPV(reactive-power-variation) anti-islanding method for grid-connected three-phase PVPCS (3상 계통연계형 태양광 PCS의 단독운전검출을 위한 개선된 무효전력변동기법)

  • Lee, K.O.;Jung, Y.S.;So, J.H.;Yu, B.G.;Yu, G.J.;Choi, J.Y.;Choy, I.
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.1159-1160
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    • 2006
  • As the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, this has raised potential problems of network protection on electrical power system. One of the numerous problems is an Island phenomenon. There has been an argument that because the probability of islanding is extremely low it may be a non-issue in practice. However, there are three counter-arguments: First, the low probability of islanding is based on the assumption of 100% power matching between the PVPCS and the islanded local loads. In fact, an island can be easily formed even without 100% power matching (the power mismatch could be up to 30% if only traditional protections are used, e.g. under/over voltage/frequency). The 30% power-mismatch condition will drastically increase the islanding probability. Second, even with a larger power mismatch, the time for voltage or frequency to deviate sufficient to cause a trip, plus the time required to execute the trip (particularly if conventional switchgear is required to operate), can easily be greater than the typical re-close time on the distribution circuit. And, third, the low-probability argument is based on the study of PVPCS. Especially, if the output power of PVPCS equals to power consumption of local loads, it is very difficult for the PVPCS to sustain the voltage and frequency in an island. Unintentional islanding of PVPCS may result in power-quality issues, interference to grid-protection devices, equipment damage, and even personnel safety hazards. So the verification of anti-islanding performance is strongly needed. In this paper, the authors propose the improved RPV method through considering power quality and anti-islanding capacity of grid-connected three-phase PVPCS in IEEE Std 1547 ("Standard for Interconnecting Distributed Resources to Electric Power Systems"). And the simulation and experimental results are verified.

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State Transition Diagram을 이용한 신규 정보통신 서비스의 대체/보완관계 분석: 와이브로(WiBro) 서비스를 중심으로

  • An Jae-Hyeon;Kim Mun-Gu;Han Sang-Pil;Park Bong-Won;Lee Sang-Yun;Bang Yeong-Seok
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.10a
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    • pp.304-316
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    • 2004
  • When new services are introduced, one of the drivers for market performance of them is the interactions among existing and new services. They are characterized by the substitution or complementary effects among existing and new service or the cannibalization of existing services by new services. This paper analyzes these issues in the telecommunications service industry context. To analyze them, a simple graphical tool or State Transition Diagram(STD) is developed and used. The diagram helps to clearly represent and explain the substitution, complement and cannibalization impact. Then, using the face-to-face survey of 1,200 people, a new wireless internet access service or WiBro is analyzed to identify the substitution/complement and cannibalization impacts in relation with the other competing services. Additionally, the important factors explaining customer subscription and substitution behavior are identified. The analysis results indicate that males, students or on-line game users are more likely to subscribe WiBro. Also, among the potential WiBro subscribers, customers who are less satisfied with the existing fixed line broadband internet access services are more likely to stop subscribing the fixed line service, which implies substitution by a new service. Additionally, this raises the issue of cannibalization if the existing and new services are provided by the same company. In fact we find the cannibalization effect is more serious for the cost sensitive group. We believe that our tool, approach, analysis results and their implications would be very helpful to devise a winning strategy for the new services in the highly uncertain telecommunications business environment.

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Development of Onesegment Receiver for Car using Cooperative Reception Diversity based on Integrated Services Digital Broad-casting Terrestrial (ISDB-T기반의 협력수신 다이버시티를 이용한 차량용 원세그 수신기 개발)

  • Yoon, Dal-Hwan;Cho, Myun-Gyun;Lin, Chi-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.12
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    • pp.66-72
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    • 2011
  • In Japan, the specification for digital terrestrial television broadcasting systems has been approved for employing a transmission scheme for ISDB-T, which can accommodate HDTV service and portable mobile reception by adapting segmentation of frequency. In this paper, we have developed 3.5 inch mobile TV according to One-Seg system and presented the results of our development. In addition, we introduce two diversity schemes to compensate the defect that signal is interrupted when the portable TV is moving fast. In order to achieve a reliable communication in One-Seg system, we introduce STD(space time diversity) which uses more than 2 antennas at TX and cooperative reception diversity which utilizes signal-exchanging between different mobile terminals. And, its performance enhancements to reception reliability of previous system are evaluated by computer simulations.

A Measurement of Sea Transportation Load (해상운송 하중측정)

  • Jeon, Yeong-Du;Park, Jong-Chan;Jo, Cheol-Hun;Park, Dong-Su;Jeong, Ui-Seung
    • Aerospace Engineering and Technology
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    • v.5 no.2
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    • pp.143-148
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    • 2006
  • This article summarizes the results of sea transportation load measurements, which will be used as the reference to the sea transportation environment condition for the launch vehicle of KSLV-I. KSLV-I will be transported by Sea from Pusan to the NARO space center in Gohung, Chunnam province. Since the vibration load condition during sea transportation is considered as one of the important design parameters of KSLV-I and its transportation means, it is necessary to directly measure the environmental condition of sea transportation loads prior to establish the sea transportation plan in detail. This material includes the measured data of 3-axis linear accelerations and 3-axis angular rates on the board of a barge-ship, which is towed by a tug boat during shipping operation. This barge-ship is same class with one which will actually carry KSLV-I. The results show that the measured load condition during sea transportation is not severer than the reference data of MIL-STD-810F and Zenit-3SL launch system.

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