• Title/Summary/Keyword: proportionality factor

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Estimation of Transpiration Rate with a Metering Pump and its Application in Soilless Culture System (정량펌프를 이용한 무토양재배시스템의 증산량 추정 및 그 응용)

  • Son, Jung-Eek;Park, Jong-Seok
    • Horticultural Science & Technology
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    • v.16 no.1
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    • pp.25-26
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    • 1998
  • Nutrient supplying by a metering pump often produces the inaccuracy in the rate of inflow than expected. In this study, we developed the transpiration estimation system using the metering pump to measure the continuous supplying rate as well as to estimate the accurate transpiration rate. The system showed the stable characteristics by eliminating the fluctuations in the head loss of nutrient tank. The direct proportionality between the supplying time and the supplied nutrient solution was obtained. The exact correlation between the integrated solar radiation and the transpiration rate using the system was calculated, and correlation coefficients between the two factors were 0.98 in the NFT system and 0.92 in the aggregate system. This results suggest that the integrated solar radiation was an important factor to directly decide the supplying volume of nutrient solution in soilless culture system. The deveolped system using the metering pump in the study was able to control the supply of the nutrient solution to the crops adjusting to the variation of solar radiation.

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A Study on Selected Transverse Bed Slope Models in Channel Bend (유로만곡부의 횡방향 하상경사 산정 모형에 관한 연구)

  • Song, Jai Woo;Choi, In Ho;Kim, Ji Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.6
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    • pp.1395-1404
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    • 1994
  • Transverse bed slope in bend is a subject of scientific investigation since it provides the necessary information for channel design and protection of hydraulic structures (bank, bridge, etc), and study of river morphology. In this paper, selected models were examined and compared for the value of prediction of the transverse bed slope in curved alluvial channels(project area), by using field data, and fitting model was proposed. All models that related the local transverse bed slope to mean flow characteristics were alike in the sense that they predicted the local transverse bed slope to be proportional to the ratio between depth and radius of curvature. The difference among the models was related with the factor of proportionality, K. Also, measured transverse bed slope was correlated to mean velocity, maximum depth, and density Froude number in channel bend. In this paper selected models were compared for the prediction of the transverse bed slope using Odgaard's experiment (obtained in Sacramento River bend), so Odgaard89 model was closely related with real transverse bed slope.

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Historical and International Legal Study on Security Characteristics of the Peace Line (평화선의 안보적 성격에 관한 역사적·국제법적 고찰)

  • Yang, Jae Young
    • Strategy21
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    • s.44
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    • pp.291-322
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    • 2018
  • This research aims to cast light upon security characteristics of the Peace Line, which have been underestimated. To understand maritime order and maritime security policy of the Republic of Korea between 1950 and 1970, it is necessary to analyze the Peace Line as line of defence and to investigate its character This research begins with analyzation of historical facts and investigation on security characteristics of the Peace Line. It goes further to examination of legal justification of the Peace Line, which was one of international legal issues of the period, principally regarding its security characteristics. As results of the study, it could be said that the security characteristics of the Peace Line was the line of defensive waters, which set its goal mainly to prevent infiltration of communist spies. The Peace Line had practical effect as it functioned as a base line of the ROK Navy to take anti-spy operation. At the early phase of the Korea-Japan Negotiation, the Korea delegation interpreted significance of the Peace Line passively. After abrogation of Clark Line, the delegation, however, became positive to maintain the Peace Line and its security characteristics. Security characteristics of the Peace Line was recognized again, as it became the base line of special maritime zone which was made in 1972. Through analysis on international law, it is concluded that the Peace Line was fair as a part of the right of self-defense against indirect aggression. North Korea attempted indirect aggression mainly from sea way, and these might undermine peace and cause urgent and unjust damage on the ROK. Thus the ROK's action of anti-spy operation through the Peace Line can be justifiable as considering the right of self-defence. Also the Peace Line accorded with principles of necessity, immediacy and proportionality. As it was argued on the above, the Peace Line as line of defence was one of the most significant factor in the ROK's maritime security history from the Hot war against communist forces to Cold war period after Korean War and must not be underestimated.

A Study on the Limits in the Use of Force against a Hijacked Civil Aircraft (피랍 민간항공기에 대한 무력행사의 한계에 관한 연구)

  • Kim, Man-Ho
    • The Korean Journal of Air & Space Law and Policy
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    • v.19 no.1
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    • pp.141-163
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    • 2004
  • The limits in the use of force against a civil aircraft which intrudes into sovereign airspace have not been defined in the aspect of international law. Therefore, this paper intends to analyze international laws and practices about sovereign airspace intrusions by the civil aircraft, and to examine the legality in the use of force against the civil aircraft hijacked by means of political terrorism, in particular. In this paper, the sphere of study is restricted within the problems of interception against the civil aircraft which intrudes into sovereign airspace in times of peace, excluding the problems against a state aircraft, and the responsibilities for the civil or criminal affairs due to interceptions. Herein this paper analyzes the existing international laws and the cases of each nation's use of force against the civil aircraft which intrudes into sovereign airspace, and organizes the conditions in the use of force which have been accepted in international laws and practices, and then applies them to the special case of civil aircraft hijacked by political terrorism. Consequently, this paper suggests that the basic principles of necessity, ultimateness, and proportionality be taken into consideration in the use of force against civil aircraft which intrudes into sovereign airspace. This study finally suggests that the possibility in the use of force against civil aircraft hijacked by political terrorism might be higher than any type of civil aircraft intrusions into sovereign airspace due to the factor of necessity of national security concerned.

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Constitutional Limits of the Medical Fee Payment System and the Unconstitutionality of Fixed Payment System (진료수가제도의 헌법적 한계와 정액수가제의 위헌성 -헌법재판소 2020. 4. 23. 선고 2017헌마103 결정을 중심으로-)

  • Hyun, Doo-youn
    • The Korean Society of Law and Medicine
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    • v.21 no.1
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    • pp.69-105
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    • 2020
  • In the health care system, medical fee payment is a very important and basic factor. The National Health Insurance Act adopted a contract system, and the content of the contract is to be determined the unit price per relative value scale. Accordingly, in the National Health Insurance system, the costs of health care benefits are adjusted each year according to inflation or changes in economic conditions. On the other hand, in the Medical Care Assistance system, the Medical Care Assistance Act does not prescribe the method of determining the medical payment, and all matters are delegated to the Minister of Health and Welfare. Accordingly, the Minister has adopted a fixed-payment system for hemodialysis treatment since 2001. A constitutional petition was filed in 2017 against this fixed-payment system, and the Constitutional Court rejected the petition in 2020. In this study, we examine the meaning and content of the medical fee payment system, focusing on the above constitutional petition case, and present three principles as constitutional limits on the system. The first of its principles is the principle of legality, the second is the principle of prohibition of comprehensive delegation, and the third is the principle of proportionality. From that point of view, There are many unconstitutional elements in the fixed-payment system on hemodialysis.

A Study on Balanced -type Oseillating Mole-Drainer(III)-Model Test for Draft Force, Torque, Power and Moment (평행식 진동탄환 암거 천공기의 연구(III)-견인력, 토크, 동력 및 모멘크에 관한 모형시험-)

  • 김용환
    • Journal of Biosystems Engineering
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    • v.1 no.1
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    • pp.1-6
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    • 1976
  • This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

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