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Front-End Design for Underwater Communication System with 25 kHz Carrier Frequency and 5 kHz Symbol Rate (25kHz 반송파와 5kHz 심볼율을 갖는 수중통신 수신기용 전단부 설계)

  • Kim, Seung-Geun;Yun, Chang-Ho;Park, Jin-Young;Kim, Sea-Moon;Park, Jong-Won;Lim, Young-Kon
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.166-171
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    • 2010
  • In this paper, the front-end of a digital receiver with a 25 kHz carrier frequency, 5 kHz symbol rate, and any excess-bandwidth is designed using two basic facts. The first is known as the uniform sampling theorem, which states that the sampled sequence might not suffer from aliasing even if its sampling rate is lower than the Nyquist sampling rate if the analog signal is a bandpass one. The other fact is that if the sampling rate is 4 times the center frequency of the sampled sequence, the front-end processing complexity can be dramatically reduced due to the half of the sampled sequence to be multiplied by zero in the demixing process. Furthermore, the designed front-end is simplified by introducing sub-filters and sub-sampling sequences. The designed front-end is composed of an A/D converter, which takes samples of a bandpass filtered signal at a 20 kHz rate; a serial-to-parallel converter, which converts a sampled bandpass sequence to 4 parallel sub-sample sequences; 4 sub-filter blocks, which act as a frequency shifter and lowpass filter for a complex sequence; 4 synchronized switches; and 2 adders. The designed front-end dramatically reduces the computational complexity by more than 50% for frequency shifting and lowpass filtering operations since a conventional front-end requires a frequency shifting and two lowpass filtering operations to get one lowpass complex sample, while the proposed front-end requires only four filtering operation to get four lowpass complex samples, which is equivalent to one filtering operation for one sample.

Study on torso patterns for elderly obese women for vitalization of the silver clothing industry - Applying the CLO 3D program - (실버 의류산업 활성화를 위한 노년 비만여성의 토르소 원형 연구 - CLO 3D 가상착의 시스템 활용 -)

  • Seong, Ok jin;Ha, Hee Jung
    • The Research Journal of the Costume Culture
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    • v.25 no.4
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    • pp.476-487
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    • 2017
  • The purpose of this study was to suggest torso patterns that fit the three main body shapes of elderly obese women. To reduce time, costs, and also the trial and error needed to make patterns, the CLO program for 3D test wear was employed. Three virtual models for aged obese women were use, with the YUKA system used to produce torso patterns. 3D simulation of test wear and corrections was done to design optimal torso patterns. The results were as follows: First, for the three models of obese women's body shapes as realized by CLO 3D, Type 1 is lower-body obesity shapes, Type 2 is abdominal obesity shapes, and Type 3 is whole-body obesity shapes. Second, to design the study patterns, actual measurement values, back waist length and waist to hip length, were used. The armhole depth (B/4-1.5), front interscye (B/6+2.3), front neck width (B/12-0.5), front neck depth (B/12+0.5), front waist measurement (W/4+ 1.5+D), front hip measurement (H/4+2+0.5), and back hip measurement (H/4+3-0.5) were calculated using formulas. Third, according to the results of test-wearing the study patterns, reduced front neck width and depth improved the neck fit and reduced armhole depth bettered loose or plunging armhole girth and also reduced the sagging of bust c.. Also, tight sidesfrom aprotruded waist and abdomen improved with the increase of surpluses in the back waist and also back and front hip c. The exterior was enhanced by displacement of back and front darts, which distributed surpluses better.

Wind-induced Spatial and Temporal Variations in the Thermohaline Front in the Jeju Strait, Korea

  • Han, In-Seong;Suh, Young-Sang;Seong, Ki-Tack
    • Fisheries and Aquatic Sciences
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    • v.16 no.2
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    • pp.117-124
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    • 2013
  • We investigated the short-term and local changes in the thermohaline front in the Jeju Strait, Korea, which is usually formed during winter and spring. To do so, we compared Real-Time Observation System by Ferryboat (RTOSF) data with wind data and routinely collected oceanographic data. During February and April 2007, a thermohaline front formed in the Jeju Strait around the 13-$14^{\circ}C$ isotherms and 33.0-33.5 isohalines. The thermohaline was clearly weakened and began moving southward in mid-March. The variations in the surface temperature and salinity showed a continuous north-south oscillation of the thermohaline front with a period of 3-10 days. The speed of the short-term and local fluctuation of thermohaline front was about 5-30 cm/s. We confirmed these findings by examining the variation in the maximum temperature gradient and $14^{\circ}C$ isotherm during the study period. These short-term and local changes had not been previously detected using serial oceanographic and satellite data. Analysis of local wind data revealed a northerly wind fluctuation with a period of 3-10 days, which was clearly related to the short-term and local changes in the thermohaline front. The short-term and local changes of the thermohaline front in the Jeju Strait originated from local changes in the winter monsoon in this area.

Two-Dimensional Moving Blade Row Interactions in a Stratospheric Airship Contra-Rotating Open Propeller Configuration

  • Tang, Zhihao;Liu, Peiqing;Guo, Hao;Yan, Jie;Li, Guangchao
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.4
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    • pp.500-509
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    • 2015
  • The numerical simulation of two-dimensional moving blade row interactions is conducted by CFD means to investigate the interactions between the front and rear propeller in a stratospheric airship contra-rotating open propeller configuration caused by different rotational speeds. The rotational speed is a main factor to affect the propeller Reynolds number which impact the aerodynamic performance of blade rows significantly. This effect works until the Reynolds number reaches a high enough value beyond which the coefficients become independent. Additionally, the interference on the blade row has been revealed by the investigation. The front blade row moves in the induced-velocity field generated by the rear blade row and the aerodynamic coefficients are influenced when the rear blade row has fast RPMs. The rear blade row moving behind the front one is affected directly by the wake and eddies generated by the front blade row. The aerodynamic coefficients reduce when the front blade row has slow RPMs while increase when the front blade row moves faster than itself. But overall, the interference on the front blade row due to the rear blade row is slight and the interference on the rear blade row due to the front blade row is much more significant.

A Study on the Original Form of Slacks of Elderly Women in Their Late 60s (60대 후반 노년 여성의 슬랙스 원형 연구)

  • Moon, Soon-Ei;Park, Kil-Soon
    • The Research Journal of the Costume Culture
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    • v.19 no.5
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    • pp.929-944
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    • 2011
  • The purpose of this study was to compare and analyze two original forms of slacks for thesis to extract outward appearance of design original form applying design measures of the above through diverse research methods. The results of this study are as follow: In original form F, the original form of slacks sloper suitable to elderly women 65~9 years old was W/4+3.5+0.5cm in the front/back circumference of waist, H/4cm in the front/back circumference of hip, (H/4+1+3.8)/2cm in the position of centerline, 19cm in actual measurement value of hip length, 25cm in actual measurement value of crotch depth, (knee crotch circumference~bottom line)/2+10cm and 90 (side waist dot~ lateral malleolus length)cm in actual measurement. front dart position was 1/3 and 2/3 of front waist centerline and back dart position was 1/3 and 2/3 of back waist circumference. It was suggested that front dart quantity (length) was 3.5(11)cm, back dart quantity 3.4 (10.2)cm, side waist up quantity 0.7cm, back down quantity 1.5cm, front crotch width (H/4+1)/4-1cm, back crotch width (H/4+1)/4+4, front knee width 21.8cm, back knee width 24.4cm, front pant leg 20.8cm, and back pant leg 23.4cm.

A Study of Jeogori Design Pattern using the Pattern Analysis in the Books Entitled Hanbok Construction Focusing on the Women in 20's (성인여성 저고리 패턴을 활용한 개선된 저고리 패턴설계연구 - 20대 여성용 저고리를 중심으로 -)

  • Kim, Hyun-Ju;Chang, Min-jung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.4
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    • pp.1-14
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    • 2015
  • This study mainly analyzes that designing patterns of an adult women Jeogori that takes advantage of patterns from each textbooks and complements the disadvantages based on the analysis of data from the dress evaluation and comparison of materials. The modification of a size specification is needed for the standard body as an adjust of the length of Jogori between front and back, mediation for bust width between front and back, a movement for the based line of Sup and Godae. As a result, the suitable pattern according to the standard somatotype is as below. Jeogori Length of front is determined by the length of back which was measured from side neck point to bust point plus three centimeters, and give three and half centimeters more in front. This three and half centimeters is for the curved in front of your body due to the chest. Bust width of front and back have to show the differences of human body. Bust width of front is calculated as bust girth into quarters and add two centimeters. Bust width of back gives one centimeter behind the curve from the center line in order to reduce the floating phenomenon. So, the amount of center back line dart is one centimeter. Arm hole girth measures as dividing bust girth into four. Also, Goedae width has two methods to measure. First, divide bust girth into ten equal parts and subtract 0.5 centimeters from it. Second, measure neck girth and divide it by four. Sleeve length is equal to Hwajang minus bust width of front. Hand wrist calculates in using bust girth. Make bust girth into quarters and multiply three fifths. Side line measures as deducting from Jeogori length of back to Arm hole girth and multiply two thirds.

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A Study on The Common Form of Timber Framework of Folk House in Yeosu City (여수지역 재래 민가(在來 民家) 가구(架構) 구성의 공통형에 관한 연구)

  • Park, Chan;Watanabe, Masahiro;Kim, Jeong-Gyun
    • Journal of the Korean Institute of Rural Architecture
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    • v.19 no.4
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    • pp.67-75
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    • 2017
  • This paper overall and systematically investigates of basic design know-how on commonly indwelling timber framework in a folk house in Yeosu area. in other words, Setting the goal of 'investigates of common form of timber framework', and for this goal, surveyed and analyzed for folk house a lot of findable in Yeosu area. As a result, elicits for four types plural common form((1) 4 front 'kan' - a hipped roof construction - front 'toi'/3 'ryang' - no central pillar/side beam type, (2) 4 front 'kan' - a hipped roof construction - front 'toi'/3 'ryang' - one side central pillar/central side beam type, (3) 4 front 'kan' - a hipped roof construction - front/back 'toi'/2'kozu'5'ryang' - no central pillar/side beam type, (4) 4 front 'kan' - a hipped roof construction - front/back 'toi'/'2kozu'5'ryang' - one side central pillar/central side beam type). Common form is at that time, so commonly located in the head of the technician that a form that play an exemplary role in design, or it is concretely assumed for commonly aimed form. in other words, Common form is come into existence on premise for basic design data. Documentation of folk house design know-how is done through this, and the base design and specification of korean private house is written in the contents divided into by areas.

Difference between Consumers' and Front-line Workers' Perceptions on Consumer Complaint Behavior with Hateful Intentions: Based on the Personal and Social Factor (소비자의 부적절한 불평행동에 대한 소비자와 사업자의 인식 차이 연구 : 개인적 요인, 사회적 요인)

  • Kim, Hye Jin;Lee, Seung Sin
    • Human Ecology Research
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    • v.56 no.1
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    • pp.15-32
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    • 2018
  • This study analyzes difference in consumers' and front-line workers' perceptions on 'consumer complaint behavior with hateful intentions' though the Co-orientation Model in three dimensions. In addition, we seek to contribute to reducing the conflict between consumers and front-line workers in the service contact point by finding factors that affect the difference in perception between two parties. This study findings and implications are as follows. First, Taking a look at the mutual orientation between consumers and front-line workers, mutual perceptions have been found to match in agreement but with a significant difference in perceived agreement (congruence), which indicates that the internal perceptions of both consumers and front-line workers do not match. The findings confirm that consumers and front-line workers have different perspectives on consumer complaint behavior with hateful intentions and therefore raise a need for efforts and institutional devices for improvement. Second, the study has found that consumers' economic responsibility as part of their social responsibilities and front-line workers' perceptions on consumers' civic responsibility affect the perception difference between these two groups and suggest a need for educating consumers about economic responsibility. Meanwhile, unlike consumers, front-line workers view consumers' complaint behavior with hateful intentions from an ethical point of view, raising a need for a transition of perspectives on complaint behavior with hateful intentions.

New On-Chip RF BIST(Built-In Self Test) Scheme and Circuit Design for Defect Detection of RF Front End (RF Front End의 결함 검출을 위한 새로운 온 칩 RF BIST 구조 및 회로 설계)

  • 류지열;노석호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.449-455
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    • 2004
  • This paper presents a novel defect detection method for one chip RF front end with fault detection circuits using input matching measurement. We present a BIST circuit using 40.25{\mu}m$ CMOS technology. We monitor the input transient voltage of the RF front end to differentiate faulty and fault-free RF front end. Catastrophic as well as parametric variation fault models are used to simulate the faulty response of the RF front end. This technique has several advantages with respect to the standard approach based on current test stimulus and frequency domain measurement. Because DUT and fault detection circuits are implemented in the same chip, this test technique only requires use of digital voltmeter (RMS meter) and RF voltage source generator for simpleand inexpensive testing.

A Study on the Swept Path Width for the Bimodal Tram (바이모달 트램 곡선 선회폭에 관한 연구)

  • Moon, Kyeong-Ho;Chang, Se-Ky;Mok, Jai-Kyun
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.51-56
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    • 2011
  • The train travels on the track and, thus, the rear wheels precisely follow the paths of the front wheels. On the contrary, in the vehicles running on the road like automobiles, buses and trucks, the front wheels try to drag the rear ones toward them and across the inside of the curve. Off-tracking is defined as the radial offset between the path of the centerline of the front axle and the path of the centerline of the following axle. In the case of the bimodal tram with AWS(all wheel steering), the off-tracking decrease but the rear swing-out values increase because of the rear steering at the reverse phase angle. Thus, in order to determine the swept path width, maximum road width at the minimum turning radius, off-tracking and swing-out should be considered for the bimodal tram. In this paper, trajectory simulations were carried out for the various condition such as front steering, front and rear steering and suppression of swing-out to optimize the swept path width.

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