• Title/Summary/Keyword: Pitch distance

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Development of Automatic Nut Inspection System using Image Processing (이미지 프로세싱을 이용한 자동 너트 검사 장비 개발)

  • Lee, Sang-Hak;Seo, Myong-Ho;Chung, Tae-Choong
    • The KIPS Transactions:PartA
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    • v.11A no.4
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    • pp.235-242
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    • 2004
  • When manufacturing information and communication device that consists of lots of part, it is important to improve the quality of the produced system by inspecting the system accurately and exclude the defected part. In case of LCD which is recently in a great demand, the inspection process of the nut which bonds the back frame to protect the LCD panel has to be done by human labor. It highly required an automatic inspection system which can inspect the nut without wasting human resources. In this paper, we describe the process of developing a system which automatically inspect the status of nuts inserted during the manufacturing of LCD. The nut inspection vision system developed measures the number of nut's spiral, the distance between pitches, the width of a pitch, and the inside diameter of nut. We have adopted lens with high magnifying power and calibration tool and intended to produce automatic lighting for maintaining a stable environment for a high precision system. We also developed the algorithms for analyzing the nut. We apply the system to real factory field and verify that it is better than the man power in terms of error rate.

Classification of Porcine Wasting Diseases Using Sound Analysis

  • Gutierrez, W.M.;Kim, S.;Kim, D.H.;Yeon, S.C.;Chang, H.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.8
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    • pp.1096-1104
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    • 2010
  • This bio-acoustic study was aimed at classifying the different porcine wasting diseases through sound analysis with emphasis given to differences in the acoustic footprints of coughs in porcine circo virus type 2 (PCV2), porcine reproductive and respiratory syndrome (PRRS) virus and Mycoplasma hyopneumoniae (MH) - infected pigs from a normal cough. A total of 36 pigs (Yorkshire${\times}$Landrace${\times}$Duroc) with average weight ranging between 25-30 kg were studied, and blood samples of the suspected infected pigs were collected and subjected to serological analysis to determine PCV2, PRRS and MH. Sounds emitted by coughing pigs were recorded individually for 30 minutes depending on cough attacks by a digital camcorder placed within a meter distance from the animal. Recorded signals were digitalized in a PC using the Cool Edit Program, classified through labeling method, and analyzed by one-way analysis of variance and discriminant analysis. Input features after classification showed that normal cough had the highest pitch level compared to other infectious diseases (p<0.002) but not statistically different from PRRS and MH. PCV2 differed statistically (p<0.002) from the normal cough and PRRS but not from MH. MH had the highest intensity and all coughs differed statistically from each other (p<0.0001). PCV2 was statistically different from others (p<0.0001) in formants 1, 2, 3 and 4. There was no statistical difference in duration between different porcine diseases and the normal cough (p>0.6863). Mechanisms of cough sound creation in the airway could be used to explain these observed acoustic differences and these findings indicated that the existence of acoustically different cough patterns depend on causes or the animals' respiratory system conditions. Conclusively, differences in the status of lungs results in different cough sounds. Finally, this study could be useful in supporting an early detection method based on the on-line cough counter algorithm for the initial diagnosis of sick animals in breeding farms.

A Comparative Analysis of Content-based Music Retrieval Systems (내용기반 음악검색 시스템의 비교 분석)

  • Ro, Jung-Soon
    • Journal of the Korean Society for information Management
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    • v.30 no.3
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    • pp.23-48
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    • 2013
  • This study compared and analyzed 15 CBMR (Content-based Music Retrieval) systems accessible on the web in terms of DB size and type, query type, access point, input and output type, and search functions, with reviewing features of music information and techniques used for transforming or transcribing of music sources, extracting and segmenting melodies, extracting and indexing features of music, and matching algorithms for CBMR systems. Application of text information retrieval techniques such as inverted indexing, N-gram indexing, Boolean search, truncation, keyword and phrase search, normalization, filtering, browsing, exact matching, similarity measure using edit distance, sorting, etc. to enhancing the CBMR; effort for increasing DB size and usability; and problems in extracting melodies, deleting stop notes in queries, and using solfege as pitch information were found as the results of analysis.

Kinematic Analysis of Hurdle Clearance Technique for 110-m Men's Hurdlers at IAAF World Championships, Daegue 2011 (2011 대구세계육상선수권대회 110m 허들 선수의 허들링 기술 동작의 운동학적 분석)

  • Park, Young-Jin;Ryu, Jae-Kyun;Ryu, Ji-Seon;Kim, Tae-Sam;Hwang, Won-Seob;Park, Sang-Kyoon;Yoon, Suk-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.21 no.5
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    • pp.529-540
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    • 2011
  • The purpose of this study was to evaluate the kinematic characteristics of $5^{th}$ and $6^{th}$ hurdle clearances during the final of the 110-m hurdles at the IAAF World Championships, Daegu 2011. To this end, the hurdling motions of the top 4 ranked male hurdlers in the competition were analyzed. A total of 12 cameras were used to record their motions, with a sampling frequency of 120 Hz. The cameras were calibrated using $11{\times}2{\times}1\;m$ control objects that covered all of the lanes (1st~8th lanes). After analyzing all the data, we arrived at the following results. In the take-off phase, all athletes revealed similar take-off times (CT), and similar distances from the take-off to hurdleto (L1) and hurdle to landing (L2). In particular, Turner, ranked $3^{rd}$, had an inconsistent L2 and may need further training to correct it. In the flight phase, Richardson, ranked $1^{st}$, showed the longest flight distance, whereas Xiang, who was ranked $2^{nd}$, showed the highest CG height from the hurdle. For the step patterns, to increase the pitch frequency, Richardson and Xiang used shorter 3-step lengths than Turner and Oliver.

A Study on Link Analysis of Telemetry Rocket-borne Antenna (텔레메트리 로켓 탑재 안테나의 회선 분석에 관한 연구)

  • 김성완;황수설;이재득
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.3
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    • pp.311-318
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    • 2004
  • It is required to design the RF link with sufficiently stable signal margin to minimize bit errors and improve the quality of received data in the telemetry system modulated digitally like PCM/FM. In case of the vehicle flying at a high speed, the variation of the gain pattern between transmitting and receiving antenna and the fee space loss due to flight distance cause the fluctuation of link. In this paper, KSR(Korea Sounding Rocket)- III, the first domestic liquid rocket which was successfully launched in Nov. 2002 is introduced. The SNR(signal-to-noise ratio) variation of the telemetry signal which was measured at S-band ground station, the one which was simulated considering the flight trajectory, and the attitude variation such as roll, pitch and yaw are compared, analyzed, and agree very well. In addition, two virtual flying situations are simulated and evaluated-only one antenna is equipped in one case, and rocket is roll-free in the other.

Heat Transfer Measurement by a Round Jet Impinging on a Rib-Roughened Concave Surface (표면조도를 가지는 오목한 면에 충돌하는 원형제트에 의한 열전달 측정)

  • Lee, Dae Hee;Won, Se Youl;Lee, Joon Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.6
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    • pp.734-743
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    • 1999
  • The local Nusselt numbers have been measured for a round turbulent jet impinging on the concave surface with and without rib. Liquid crystal/transient method was used to determine the Nusselt number distributions along the surface. The temperature on the surface was measured using liquid crystal and a digital color image processing system. The experiments were made for the jet Reynolds number (Re) 23,000, the dimensionless nozzle-to-surface distance (L/d) from 4 to 10, the dimensionless surface curvature (d/D) 0.056, and the rib type (height ($d_1$) 0.2 cm, pitch (p) from 1.2 to 3.2 cm). It was founded that only when $L/d{\geq}6$, the average Nusselt numbers on the concave surface with rib are higher than those without rib, mainly due to an increase in the turbulent intensity caused by the effect of rib attached to the wall surface. It was realized that the rib attached to the concave surface may no longer enhance the heat transfer rate or even lowers it depending on the rib type and flow conditions. In addition, the results by the steady-state method using the gold-film Intrex were in good agreement with those by the transient shroud method.

Approximate Friction and Gravity Compensation in Haptic Laparoscopic Surgery Simulator (햅틱 복강경 수술 시뮬레이터의 마찰력 및 중력 보상)

  • Kim, Sang-Hyun;Lee, Chang-Gyu;Kim, Ji-Suk;Ryu, Je-Ha
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.8
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    • pp.883-888
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    • 2011
  • Laparoscopic surgery is being used in various surgical fields because it minimizes scarring. Laparoscopic operations require practical hand skills, so surgeons train on animals and via surgery training tool sets. However, these tool sets do not give the surgeon the sensation of touching real organs. A recently developed laparoscope simulator has a high friction force along the translational axis and a high gravity force along the pitch axis, and therefore it does not permit the operator to control his or her hands delecately. In the paper, the friction force along the axes is auumed to depend on the veolcity, and the gravity force on the angle and distance. We develop a compensation model that combines the gravity and friction force models.

Effect of Duct Aspect Ratios on Pressure Drop in a Rotating Two-Pass Duct (덕트 종횡비가 회전덕트 내 압력강하에 미치는 영향)

  • Kim Kyung-Min;Lee Dong-Hyun;Cho Hyung-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.6 s.249
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    • pp.505-513
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    • 2006
  • The pressure drop characteristics in a rotating two-pass duct with rib turbulators are investigated in the present study. Three ducts of different aspect ratios (W/H=0.5, 1.0 and 2.0) are employed with a fixed hydraulic diameter ($D_h$) of 26.7 mm. $90^{\circ}$-rib turbulators with $1.5mm{\times}1.5mm$ cross-section are attached on the leading and trailing surfaces. The pitch-to-rib height ratio (p/e) is 1.0. The distance between the tip of the divider and the outer wall of the duct is 1.0 W. The thickness of divider wall is 6.0 mm o. 0.225 $D_h$. The Reynolds number (Re) based on the hydraulic diameter is kept constant at 10,000 and the .elation number (Ro) is varied from 0.0 to 0.2. As duct aspect ratio increases, high friction factor ratios show in overall regions. The reason is that the rib height-to-duct height ratio (e/H) increases, but the divider wall thickness-to-duct width ($t_d/W$) decreases. The rotation of duct produces pressure drop discrepancy between the leading and trailing surfaces. However, the pressure drop discrepancy of the high duct aspect ratio (AR=2.0) is smaller than that of the low duct aspect ratio (AR=0.5) due to the decrement of duct hight (H).

Postural Control During Virtual Moving Surround Stimulation in Patients with Brain Injury (뇌기능 장애 환자의 가상 환경 움직임(Virtual Moving Surround) 자극에 따른 자세 균형 제어)

  • 김연희;최종덕;이성범;김종윤;이석준;박찬희;김남균
    • Science of Emotion and Sensibility
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    • v.5 no.4
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    • pp.67-75
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    • 2002
  • The purpose of this study is to assess the ability of balance control in virtual moving surround stimulation using head mount display (HMD) device and force platform in patients with brain injury. Fifteen patients with stroke (mean age 54.47 yrs) and fifteen healthy normal persons participated. COP parameters were obtained total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) during comfortable standing with opened or closed eyes, (2) during virtual moving surround stimulation delivered using HMD with four different moving pattern. Moving patterns consisted of close-far, superior-inferior lilting (pitch) , right-left tilting (roll) and horizontal rotation (yaw) movement. In all parameters, the test-retest reliability was high. Also, the construct validity of virtual moving surround stimulation was excellent (p<0.05). A posturographic balance assessment system equiped with virtual moving surround stimulation using HMD is considered clinically useful in evaluation of balance control in patients with brain injury.

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Thrust Characteristics of Dual Flapping Airfoils in a Biplane Configuration (복엽기 배치의 복식 플랩핑 에어포일들의 추력 특성)

  • Yu, Young-Bok;Han, Cheol-Heui;Cho, Jin-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.7
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    • pp.9-17
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    • 2005
  • The wake patterns and thrust characteristics of dual flapping airfoils in a biplane configuration are investigated using an unsteady panel method. To trace complicated wake shapes behind airfoils, a core addition scheme, a vortex core model, and the fourth order Runge-Kutta convection scheme are employed. Present results are verified by comparing them with flow visualization, exact solution and published computed results. The thickness and camber of thick airfoils has an effect of decreasing thrust. The airfoils produce maximum thrust when the phase angles between plunging and pitching motions are both 90 and 120 degrees. Thrust increases as the plunge velocity is increased, which is also found as the pitch amplitude is stepped up. Thrust decreases when the distance between the airfoils is less than 0.6c.