• Title/Summary/Keyword: Korea Design Standard

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Design and Implementation of LTE-TDD 2×2 MIMO Bidirectional RF Hybrid Beamforming System (LTE-TDD 2×2 MIMO 양방향 RF 하이브리드 빔포밍 시스템 설계 및 구현)

  • Lee, Kwang-Suk;Kim, Dong-Hyun;Oh, Hyuk-Jun
    • Journal of Korea Society of Industrial Information Systems
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    • v.23 no.4
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    • pp.23-31
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    • 2018
  • This paper presented the implementation and design of the 2T-2R wireless HD video streaming systems over 1.7 GHz frequency band using 3GPP LTE-TDD standard on NI USRP RIO SDR platform. The baseband of the system used USRP RIO that are stored in Xilinx Kintex-7 chip to implement LTE-TDD transceiver modem, the signal that are transmitted from USRP RIO up or down converts to 1.7 GHz by using self-designed 1.7 GHz RF transceiver modules and it is finally communicated HD video data through self-designed 2x9 sub array antennas. It is that communication method between USRP RIO and Host PC use PCI express x4 to minimize delay of data to transmit and receive. The implemented system show high error vector magnitude performance above 32 dBc and to transmit and receive HD video in experiment environment anywhere. The proposed hybrid beam forming system could be used not only in the future 5G mobile communication systems under 6 GHz frequency band but also in the systems over 6 GHz frequency band like ones in mmWave frequency bands.

The Change Pattern of Body Shape on Chronological Age in Korea Adult Women (한국 성인 여성의 연령대별 체형변화에 대한 연구)

  • Kim, Kyoung Sun;Han, Hyunsook;Nam, Yun Ja
    • Fashion & Textile Research Journal
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    • v.19 no.1
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    • pp.49-60
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    • 2017
  • In this study, change trends and specific times for change in body size were sought to be identified by using manual measurements for Korean adult women at 20 to 89 of age, along with examinations of change trends and specific times of change in body shape based on body index values. The examinations of means, deviations, and variation coefficients revealed that there was a tendency of most height related measures to decrease. In addition, combined with decrease in height, growth in weight led to increased BMI, thus resulting in increase in measures of circumference, thickness, and breadth in the torso area. The BMI trends showed that with increasing age, BMI increased, reaching the peak between the ages of 55 and 59 and then decreasing from 64 of age, with the steepest increase in BMI at ages from 50 to 54. The examination of differences in the body flatness ratio for different parts of body found that with increasing age the ratio decreased, indicating a tendency for gradual change to round body shapes. The analysis of 3D body shape found that there were more back-bends and lowered shoulder levels with age, accompanied with a tendency for more bended legs and more inclined-forward necks. The key trends in changes in body measurements by age and detailed estimates of 3D standard body shape drawn out from this study are expected to significantly contribute to establishing a basic database for generating patterns reflecting age features of Korean adult females.

Rotordynamic Model Development and Critical Speed Estimation Through Modal Testing for the Rotor-Bearing System of a MW Class Large-Capacity Induction Motor (MW급 대용량 유도전동기 축계의 모드실험 기반 회전체 동역학 해석모델 수립 및 위험속도 예측)

  • Park, Jisu;Choi, Jae-Hak;Kim, Dong-Jun;Sim, Kyuho
    • Tribology and Lubricants
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    • v.36 no.5
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    • pp.279-289
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    • 2020
  • In this paper, a method is proposed for establishing an approximate prediction model of rotor-dynamics through modal testing. In particular, the proposed method is applicable to systems that cannot be established according to conventional methods owing to the absence of information regarding the dimensions and material of the rotor-bearing system. The proposed method is demonstrated by employing a motor dynamometer driven by a 1 MW class induction motor without dimension and material information. The proposed method comprises a total of seven steps, wherein an initial model is established by incorporating approximate dimensions and material information, and the model is improved on the basis of the natural frequency characteristics of the system. During model improvement, the modification factor is introduced for adjusting the elastic modulus and shear modulus of the system. Analysis of critical speed and imbalance response indicates that the separation margin is 67% and the maximum vibration amplitude is less than the amplitude limit of 0.032 mm under the API 611 standard, which means that the motor dynamometer can stably operate at a rated speed of 1800 rpm. Hence, the obtained results validate the feasibility of the proposed method. Furthermore, for broad usage, it is necessary to accordingly apply and validate the proposed method for various rotor-bearing systems.

Wearing Condition & Preference of Shirts for Males in Their Twenties and Thirties (20~30대 남성의 셔츠 착용실태 및 선호도 연구)

  • Seong, Hyeyun;Yi, Kyong-Hwa
    • Journal of Fashion Business
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    • v.20 no.5
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    • pp.60-75
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    • 2016
  • This research was conducted to understand the different circumstances for wearing shirts by adult males aged 20-39, and to provide this basic information to the shirt industry prior to developing new functional men's shirts. A total of 345 respondents participated in the survey. Most of questionnaire, frequency, mean and standard deviation were calculated and the differences between the 20s and 30s were analyzed by t-test or ${\chi}^2$ test. The results of the survey are as follows. Grading the satisfaction degree of their body parts, the respondents were relatively unsatisfied with their height, weight, and waist, abdominal and hip circumferences. Majority preferred department stores, discount stores and outlets for purchasing shirts. Many have never owned tailored shirts - men in 20's had less experience with tailoring than men in 30's. The foremost selection criterion for purchasing shirts was fit -during purchase, men in their 20's considered fit more important than men in their 30's. The most preferred unbuttoning of the top button when wearing shirts. For favored collar shapes with one button unbuttoned, the most valued collar angle and style was V-neck shape when unbuttoned, low collar band, collar with unopened collar, and stiff collars. Most shirt designs and details included slim fit, no dart in the front and one dart on the back. Men in 20's more preferred the no dart in the front and one tuck on the back, as compared to men in 30's. On the other hand, men in their 30's preferred one dart shirts than men in 20's. Regarding shirt bands and cuffs, one button and regular collar and one button cuffs with round angle design, were the most preferred, respectively.

Effective Compressive Strength of Corner Columns with Intervening Normal Strength Slabs (일반강도 슬래브로 간섭받은 모서리 기둥의 유효압축강도)

  • Lee, Joo-Ha
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.3
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    • pp.122-129
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    • 2015
  • In this study, a prediction model for the effective compressive strength of corner columns with intervening normal strength concrete slabs was developed. A structural analogy between high-strength concrete column-normal strength concrete slab joint and brick masonry was used to develop the prediction model. In addition, the aspect ratio of slab thickness to column dimension was considered in the models. The reliability of the new prediction model was evaluated by comparison with experimental results and its superiority was demonstrated by comparison with previous models proposed by design codes and other researchers. As a result, with average test-to-predicted ratios of 1.09, a standard deviation of 0.15, the newly developed equation provided superior predictions in terms of accuracy and consistency over all of the existing effective strength prediction approaches including KCI structural concrete design code (2012).

Dynamic Response of Steel Plate Girder Bridges by the KL-510 Load (KL-510 하중에 의한 강판형교의 동적응답)

  • Chung, Tae-Ju
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.6
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    • pp.50-60
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    • 2013
  • Dynamic response of steel plate girder bridges by KL-510 design truck in KHBDC considering the road surface roughness of bridges and bridge-vehicle interaction is investigated. Simply supported steel plate girder bridges with span length of 20m, 30m, and 40m from "Standard Highway Bridge Superstructure" published by the Korean Ministry of Construction are used for a bridge model, and ten sets of the road surface roughness of bridge deck are generated from power spectral density (PSD) function by assuming the roadway as "Average Road". A three dimensionally modeled 5-axle tractor-trailer with its gross weight, which is the same as that of KL-510 design truck, is used for dynamic analysis. For the finite element modeling of superstructure, beam element for the main girder, shell element for the concrete deck, and rigid link between main girder and concrete deck are used. Impact factor and DLA of steel plate girder bridges for different span are calculated by the proposed numerical analysis model and compared with those specified by several bridge codes.

Design of FPGA Hardware Accelerator for Information Security System (정보보호 시스템을 위한 FPGA 기반 하드웨어 가속기 설계)

  • Cha, Jeong Woo;Kim, Chang Hoon
    • Journal of Korea Society of Industrial Information Systems
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    • v.18 no.2
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    • pp.1-12
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    • 2013
  • Information Security System is implemented in software, hardware and FPGA device. Implementation of S/W provides high flexibility about various information security algorithm, but it has very vulnerable aspect of speed, power, safety, and performing ASIC is really excellent aspect of speed and power but don't support various security platform because of feature's realization. To improve conflict of these problems, implementation of recent FPGA device is really performed. The goal of this thesis is to design and develop a FPGA hardware accelerator for information security system. It performs as AES, SHA-256 and ECC and is controlled by the Integrated Interface. Furthermore, since the proposed Security Information System can satisfy various requirements and some constraints, it can be applied to numerous information security applications from low-cost applications and high-speed communication systems.

A case study on the selection process of cutoff wall for ground-water using VE/LCC analysis (VE/LCC 기법을 활용한 차수공법 선정사례 연구)

  • Cho Yong-Wan;Chang Jun-Ho;Kim Jin-Man;Ha Jae-In
    • 기술발표회
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    • s.2006
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    • pp.279-291
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    • 2006
  • This study shows decision-making process for selection of cutoff wall on a wastewater treatment project. There are 10 different cut-off wall methods So, we examine the site to gather information for find appropriate methods. After using that information, 10 cutoff wall methods are reviewed for analysis. Through brainstorming, four alternatives are selected for design VE item. Following the standard VE process, we established performance criteria and evaluated function score(F) using questionnaire. The questionnaires, brainstorming and AHP method for weighting on performance criteria and evaluate function score increased the reliability of this selection process. Water Jet method, one of four methods, has the best function score(F=92.71) and the lease construction cost(as cost index 1,000). The value score also highest as 92.7, so we select the method. The result is value innovation type In addition, the authors try to calculate the environmental burden in selection process using LCA. We cannot conduct the full LCA as defined ISO, so perform Simple LCA In LCA result, the cut-off grouting has the least environmental burden as index 9.09E+01 and Water Jet method has following as the second. To selection best method to specific area and purpose, design VE/LCG process used as useful tool and it is needed to develop integrated method that evaluate VEILCC and LCA as one-set process.

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Case Study : Application of Specific Evaluation Criteria For Safety Circuit Design of EN ISO 13849-1 (사례 연구 : EN ISO 13849-1의 안전회로 설계를 위한 구체적 평가 기준의 적용)

  • Jung, Hwansuk;Lee, Dongju
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.1
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    • pp.94-101
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    • 2018
  • With the development of industrial technology and science, production and manufacturing facilities have been enhanced and improved, and the importance of the safety of workers has also been regulated and limited by various safety management methods. As a way to secure the safety of the workers from the production facility, the fail-safe and fool-proof methods are now being applied. Any possible insecure behavior and unsafe conditions can be removed by adopting the standards and specifications that are now secure the safety of workers and equipment. This research analyzes EN ISO 13849-1 international and European standards during CE certification. In order to secure acceptable reduced risks, the risk assessment process of ISO 12100 and the processes for reducing its risk are applied. In the current ISO 13849-1 standard, the criteria for the required performance level PLr (Required Performance Level) for the applicable risk and safety functions through the risk assessment are subjective and not subdivided. Therefore, the evaluation criteria are likely to cause judge's judgement error due to qualitative judgement. This research focuses on evaluation and acceptable performance level setting for the safety circuit of the equipment. We propose an objective and specific evaluation criteria to secure safety, and the proposed evaluation criteria are applied to the case study of the safety circuit for the equipment. In order to secure the safety of the entire safety circuit, the improvement of the MTTFd and DC level related to the SRP/CS (Safety-Related Parts of Control Systems)' lifetime is required for the future research.

A Study on Safety Coordination for a Complex System Comprised of Interoperable Systems Utilizing DoD Architectural Framework (상호운용성을 요구하는 복합시스템 개발에서 DoD 아키텍처 프레임워크를 활용한 안전성 확보에 관한 연구)

  • Kim, Young-Min;Lee, Jae-Chon
    • Journal of the Korea Safety Management & Science
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    • v.15 no.1
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    • pp.1-10
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    • 2013
  • The recent trend in the war fields on the globe may be characterized by the network-centric warfare, which would, in turn, make the concept of weapon systems be changed. To this end, the concept of system of systems (SoS) has been introduced in literature. An SoS is a collection of multiple systems, each of which is an independent system and can be interoperable with each other. Thus, in defense domain each SoS is a big weapon system as a whole operated in actual environment and each element of it is also an independent smaller weapon system, but they should be interoperable via network among each other. The safety results studied for each elementary system alone may not be fully applicable to the whole SoS. As such, the objective of this paper is to study how to make the SoS safety requirements be distributed down over the interoperable elementary systems. Since handling the interoperability requires a technique of systems architecture, a standard method called the DoD Architectural Framework (DoDAF) has been used here to derive a solution. Using DoDAF, the safety requirements were first analyzed in the operability environment. The results were then studied to be included in an integrated model of both the systems design and safety processes. A further study of present paper would facilitate ensuring safety in the development of SoS weapon systems in practice.