• Title/Summary/Keyword: Speed-Measuring

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Study on the Projectile Velocity Measurement Using Eddy Current Probe (와전류 탐촉자를 이용한 총구 탄속 측정에 관한 연구)

  • Shin, Jungoo;Son, Derac
    • Journal of the Korean Magnetics Society
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    • v.25 no.3
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    • pp.83-86
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    • 2015
  • Nowadays the weapon systems are employed air bursting munition (ABM) as smart programmable 40 mm shells which have been developed in order to hit the target with programmed munition that can be air burst after a set distance in the battlefield. In order to improve the accuracy of such a bursting time, by measuring the speed of the munition from the barrel, weapon systems calculate the exact time of flight to the target and then the time information must be inputted to the munition. In this study, we introduce a device capable of detecting a shot at K4 40 mm automatic grenade. The shot is composed of a rotating copper band to convert linear motion into rotary motion when it passes through the barrel, the steel section is exert the effect of fragment and aluminum section to give fuze information. The aluminum section was used to detect munition using eddy current method. To measure muzzle velocity by means of non-contact method, two eddy current probes separated 10 cm was employed. Time interval between two eddy current probe detection times was used as muzzle velocity. The eddy current probe was fabricated U-shape Mn-Zn ferrite core with enamelled copper wire, and 200 kHz alternating current was used to detect inductance change. Measured muzzle velocity using the developed sensor was compared to the Doppler radar system. The difference was smaller than 1%.

A Study on Trade Area Analysis with the Use of Modified Probability Model (변형확률모델을 활용한 소매업의 상권분석 방안에 관한 연구)

  • Jin, Chang-Beom;Youn, Myoung-Kil
    • Journal of Distribution Science
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    • v.15 no.6
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    • pp.77-96
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    • 2017
  • Purpose - This study aims to develop correspondence strategies to the environment change in domestic retail store types. Recently, new types of retails have emerged in retail industries. Therefore, trade area platform has developed focusing on the speed of data, no longer trade area from district border. Besides, 'trade area smart' brings about change in retail types with the development of giga internet. Thus, context shopping is changing the way of consumers' purchase pattern through data capture, technology capability, and algorithm development. For these reasons, the sales estimation model has been shown to be flawed using the notion of former scale and time, and it is necessary to construct a new model. Research design, data, and methodology - This study focuses on measuring retail change in large multi-shopping mall for the outlook for retail industry and competition for trade area with the theoretical background understanding of retail store types and overall domestic retail conditions. The competition among retail store types are strong, whereas the borders among them are fading. There is a greater need to analyze on a new model because sales expectation can be hard to get with business area competition. For comprehensive research, therefore, the research method based on the statistical analysis was excluded, and field survey and literature investigation method were used to identify problems and propose an alternative. In research material, research fidelity has improved with complementing research data related with retail specialists' as well as department stores. Results - This study analyzed trade area survival and its pattern through sales estimation and empirical studies on trade areas. The sales estimation, based on Huff model system, counts the number of households shopping absorption expectation from trade areas. Based on the results, this paper estimated sales scale, and then deducted modified probability model. Conclusions - In times of retail store chain destruction and off-line store reorganization, modified Huff model has problems in estimating sales. Transformation probability model, supplemented by the existing problems, was analyzed to be more effective in competitiveness business condition. This study offers a viable alternative to figure out related trade areas' sale estimation by reconstructing new-modified probability model. As a result, the future task is to enlarge the borders from IT infrastructure with data and evidence based business into DT infrastructure.

Alkaline Pilot Processing for Recovery of Fish Muscle Protein and Properties of Recovered Protein (어육 단백질 회수를 위한 알칼리 Pilot 공정과 회수 단백질의 특성)

  • Jang, Young-Boo;Kim, Gun-Bae;Lee, Keun-Woo;Choi, Yeung-Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.8
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    • pp.1045-1050
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    • 2006
  • Optimum operation condition for pilot scale of alkaline processing for fish muscle was investigated by measuring protein solubility, yield, texture, and water-holding capacity. Recovered protein yield was 33.2% for whole fish and 61.8% for minced muscle. Optimum homogenized speed and time, using industrial scale homogenizer, were 3,000 rpm and 5 min, respectively. Limited centrifugal force of continuous cylinder type was 4,000 rpm for recovering soluble protein, and 2,000 rpm for recovering precipitated proteins. The pH control agents such as citric acid, sodium phosphate and calcium oxide decreased the breaking force and deformation of recovered protein gel. The breaking force and deformation of the recovered proteins were high compared to conventional surimi. The breaking force and deformation were decreased by addition of salt, starch and bovine plasma proteins. Whiteness of recovered protein gel was lower than that of conventional surimi. Alkaline processing greatly decreased nitrogen content and chemical oxygen demand in waste water. The results suggest that alkaline processing has a potential as industrial production for recovering the proteins from fish muscle.

The Effect of Ankle Joint Gram Walk on the Physical Function According to Treadmill Gradient (트레드밀 경사도에 따른 발목 중량부하 걷기 후 신체 기능에 미치는 영향)

  • Ko, Tae-Sung;Lee, Dong-Jin;Ryu, Jong-Ho;Jung, Tae-In;Kim, Tae-Jin;Sho, Seul-Ki;Ahn, Jin-Yeung;Yoon, Li-Na;Yoon, Mi-Ji;Lee, Da-Young;Lee, Seul-Bee;Lim, Kyung-Hee
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.8 no.2
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    • pp.25-31
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    • 2010
  • Purpose : The purpose of this study was to investigate knee muscle strength, balance, and proprioception by walking while giving weight to the ankle joint at a load of 0%, 10%, and 15% gradient on a treadmill. Methods : Twenty-four subjects were divided into three groups. Group A walked on a 0% gradient while giving weight to the ankle joint as a load. Group B walked on a 10% gradient while giving weight to the ankle joint as a load. Group C walked on a 15% gradient while giving weight to the ankle joint as a load. This was performed three times per week for four weeks. The walking speed was set at 4km/hour and the walking time was set at 20 minutes. Measurements were performed before and after the experiment. Biodex medical system and Balance system SD were used as measuring instruments. Results : There was no significant difference between the gradients in muscle strength, balance and proprioception. However, there were differences in pretest and posttest measurements for muscle strength, balance and proprioception in each gradient. In particular, the gradient of 10% showed a significant difference. Conclusion : According to the results of this study, to use a 10% gradient is effective when walking while giving weight to the ankle joint as a load.

Size measurement of electrosprayed droplets using shadowgraph visualization method (Shadowgraph 가시화 기법을 활용한 정전분무액적의 크기 측정)

  • Oh, Min-Jeong;Kim, Sung-Hyun;Lee, Myong-Hwa
    • Particle and aerosol research
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    • v.13 no.4
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    • pp.151-158
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    • 2017
  • Electrostatic precipitator is widely used to remove particulate matters in indoor air and industrial flue gas due to low pressure drop and high collection efficiency. However, it has a low collection efficiency for the submicrometer sized particles. Electrospraying is a potential method to increase the particle charging efficiency, which results in increased collection efficiency. Although particle charging efficiency is highly dependent upon droplet size, the effective measuring method of the droplets is still uncertain. Tap water was electrosprayed in this study, and the images of electrosprayed droplets were taken with a high speed camera coupled with several visualization methods in order to measure the droplets size. The droplet size distribution was determined by an image processing with an image-J program. As a result, a droplet measured by a laser visualization, had a half size of that by a Xenon light visualization. In addition, the experimentally measured droplet sizes were a good agreement with the predicted values suggested by $Fern{\acute{a}}ndez$ de la Mora and Loscertales(1994).

Experimental Analysis on Filtration-Permeation: Influence of the Type and Sheets of Filter Media, and Filtration Pressure (여과-투과에 대한 실험적 분석: 여과매체의 종류, 여과매체의 매수, 여과압력의 영향)

  • Yim, Sung-Sam;Song, Yun-Min
    • Korean Chemical Engineering Research
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    • v.50 no.2
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    • pp.317-327
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    • 2012
  • The average specific cake resistance, the most important indicator for cake filtration and solid-liquid separation, is measured by filtration experiment. But the exact value is difficult to measure because of the other influences such as sedimentation during filtration. This study, a little more stable method named filtration-permeation is proposed for measuring average specific cake resistance. The filtration-permeation is composed of permeation of particle eliminated water through pre-formed cake by filtration. Using 1 wt% calcium carbonate suspension, the filtration-permeation experiments were performed for 8 kinds of filter media at the conditions of 0.5 atm and 0.2 atm, 1 and 3 sheets of filter media. At each specific condition, three to five times filtration-permeation were accomplished. As a result, stable permeation speed is measured. According to this experimental result, the characteristics of permeation and the effect of sedimentation are analyzed with Ruth's equation. The one way analysis of variance (one way ANOVA) is applied to the average specific cake resistances of filtration and permeation obtained with the selected three kinds of filter media. The average specific cake resistances between 0.5 atm and 0.2 atm by filtration do not distinguished, but those by permeation is perfectly distinguished. The experimental results during permeation have a very narrow distribution than that measured during filtration. The analysis of filtration experiments, it was verified that the resistance of filter medium by traditional method is of no significance. Finally, the migration of small particles through the medium composed of fiber glass at low pressure was studied.

Experimental Study on Hydrofoil Arrangement and Longitudinal Moment Characteristics for Navigation Safety of High Speed Craft (고속선 운항 안정성을 위한 수중익 배치 및 종모멘트 특성에 관한 실험적 연구)

  • Park, Hwa-Pyeong;Kim, Sang-Hyun;Lim, Geun-Nam
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.4
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    • pp.443-450
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    • 2014
  • In this study, we have discussed about the effect of hydrofoil arrangement and longitudinal moment characteristic on longitudinal motion stability of fully-submerged hydrofoil by the experiment of tandem hydrofoil model. First of all, tandem hydrofoil model that has canard wing arrangement has been made and characteristics of lift force and drag force by performing the lift force and drag force measuring experiment has also been estimated. Besides, tandem hydrofoil model's wing arrangement which has the initial stability and self stability of longitudinal motion has also been determined. In longitudinal stability experiment of tandem hydrofoil model, the motion characteristic of pitch and heave and the longitudinal stability of foil borne condition by variation of self stability of longitudinal moment and longitudinal distance are estimated. The result from the experiment and it's important conclusion can be described as below; Increase the self stability for longitudinal moment, the higher self stability for pitch motions in a constant pitch angles. By increasing the self stability for longitudinal moment, the range of fluctuation of pitch motion and heave motion for pitch angle also will change relatively small and longitudinal stability is excellent. Lastly, when the lift force of hydrofoil is remain constants, we can conclude that securing the enough self stability for longitudinal moment is essential for stable foil borne condition of tandem hydrofoil.

3D Precision Measurement of Scanning Moire Using Line Scan Camera (라인스캔 카메라를 이용한 3차원 정밀 측정)

  • Kim, Hyun-Ju;Yoon, Doo-Hyun;Kim, Hak-Il
    • Korean Journal of Optics and Photonics
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    • v.19 no.5
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    • pp.376-380
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    • 2008
  • This paper presents the Projection Moire method using a line scan camera. The high resolution feature of a line scan camera makes it possible to scan an image quickly, thus enabling a much quicker 3D profile. This method uses a high resolution line scan camera making it possible to scan an image at high speed simultaneously measuring the 3D profile of a large FOV. When using a high resolution scan camera, a full FOV is scanned, thus requiring just one movement of a projection grating. As a result, the number of grating movements is reduced drastically. The end result is a faster and more accurate 3D measurement. Moving the grating too quickly causes vibration in the imaging system, which will normally be required to apply a stitching technique when using an area scan camera. However the technique is not required when using a line scan camera. Compared with the previous techniques, it has the advantages of simple hardware without moving mechanical parts - single exposure for obtaining three-dimensional information. A method using a high resolution line scan camera can be used in mass production to measure the bump height of wafers or the bump height of package substrates.

Stability of Nano-emulsions prepared upon Change of Composition (조성변화에 따라 제조된 나노에멀젼의 안정성)

  • Cho, Wan Goo;Kim, Eun Hee;Jeon, Bong-Ju;Cha, Young-Kweon;Park, Seon-Ki
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.1
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    • pp.55-63
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    • 2013
  • Applications of nano-emulsion for cosmetics as a means of promoting dermal absorption have been the subject of interest. In this study, the stability of nano-emulsions prepared by low-energy emulsification method and varying the composition of raw materials was investigated. By measuring the particle size of the nano-emulsion against time, the stability of nano-emulsions prepared by adding polyol to water phase was increased significantly compared with the nano-emulsions prepared by adding polyol to ethanol phase. The speed of adding ethanol phase to water phase did not have a significant impact on the particle size and stability. Depending on the type of oil, stability was not affected. However, there would be a correlation between the initial size of the nano-emulsion droplets and the molecular weight and polarity of the oil. Stability and the initial particle size according to the type of polyols showed a similar trend except 1,2 hexanediol. The initial droplet size was affected by the concentration of surfactant and oil. However, the initial droplet size did not change against time. Concentration of ethanol was observed to have a significant impact on the initial particle size and stability.

Micro-Study on Stock Splits and Measuring Information Content Using Intervention Method (주식분할 미시분석과 정보효과 측정)

  • Kim, Yang-Yul
    • The Korean Journal of Financial Management
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    • v.7 no.1
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    • pp.1-20
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    • 1990
  • In most of studies on market efficiency, the stability of risk measures and the normality of residuals unexplained by the pricing model are presumed. This paper re-examines stock splits, taking the possible violation of two assumptions into accounts. The results does not change the previous studies. But, the size of excess returns during the 2-week period before announcements decreases by 43%. The results also support that betas change around announcements and the serial autocorrelation of residuals is caused by events. Based on the results, the existing excess returns are most likely explained as a compensation to old shareholders for unwanted risk increases in their portfolio, or by uses of incorrect betas in testing models. In addition, the model suggested in the paper provides a measure for the speed of adjustment of the market to the new information arrival and the intensity of information contents.

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