• 한국항공운항학회지
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• 제12권3호
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• pp.41-63
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• 2004

The area covered by product liability in broadest sense is so vast that an attempt to analyse all its impact on the aviation world risk. Every effort has been made to confine our review of subject a closely as possible to its influence on aircraft manufacturers, airlines and passengers, in spite of strong connections with other spheres of commercial. Product Liability in aviation is the liability of aircraft's manufacturer, processor or non-manufacturing seller for injury to the person or property of a buyer or third party caused by a product which has been sold. Here-in a product is aircraft, third party is passengers who suffered damage by defective design, defective construction, inadequate instructions for handling in aircraft. Whenever a product turns out to be defective after it has been sold, there are under Anglo-American law three remedies available against the aircraft's manufacturer (1) liability for negligence (2) breach of warranty (3) strict liability in tort. There are Under continental law Three remedies available against the aircraft's manufacturer (1) liability for defective warranty (2) liability for non-fulfillment of obligation (3) liability in tort. It is worth pointing out here an action for breach of warranty or for defective warranty, for non-fulfillment of obligation is available only to direct purchaser on the basis of his contract with the aircraft's manufacturer, which of course weakness its range and effectiveness. An action for tort offers the advantage of being available also to third parties who have acquired the defective product at a later stage. In tort, obligations are constituted not only by contract, but also by stature and common law. In conclusion, There in no difference in principle of law. In conclusion I would like to make few suggestions regarding the product liability for aircraft's manufacturer. Firstly, current general product liability code does not specify whether government offices(e.g. FAA) inspector conducted the inspection and auditory certificate can qualify as conclusive legal evidence. These need to be clarified. Secondly, because Korea is gaining potential of becoming aircraft's manufacturer through co-manufacturing and subcontracting-manufacturing with the US and independent production, there needs legislation that can harmonize the protection of both aircraft's manufacturers and their injured parties. Since Korea is in primary stage of aviation industry, considerate policy cannot be overlooked for its protection and promotion. Thirdly, because aircraft manufacturers are risking restitution like air-carriers whose scope of restitution have widened to strict and unlimited liability, there needs importation of mandatory liability insurance and national warranty into the product liability for aircraft's manufacturers. Fourthly, there needs domestic legislation of air transportation law that clearly regulates overall legal relationship in air transportation such as carrier & aircraft manufacturer's liability, and aviation insurance.

• 한국지반공학회논문집
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• 제17권6호
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• pp.111-121
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• 2001

낙석방지울타리는 도로절개면 상부에서 발생한 낙석의 도로 유입을 차단하기 위하여 설치되는 구조물로 국내 국도 절개면 중 70%이상 시공되어 있다. 이와 같이 도로 절개면의 재해예방을 위하여 범용적으로 사용되는 시설물로서 그 중요성이 매우 강조될 수 있으나 국내의 경우 아직까지 설계 및 시공에 대한 기준이 미흡하고 절개면의 높이, 경사도 등 특성을 고려하지 않은 단일 표준단면도에 의해 설계, 시공되어 이의 효율성에 한계가 있는 것이 사실이다. 따라서, 본 연구에서는 현장실험을 통해 낙석방지울타리의 흡수가능에너지를 파악하였다. 실험을 위하여 높이 20m, 경사 65도의 절개면을 선정하여 4개 규모의 콘크리트 볼(0.7, 1.3, 2.3, 4.3 톤)을 절개면 상부로부터 낙하시켜 낙석방지 울타리의 성능을 평가하였다. 본 논문은 시공완료된 절개면을 대상으로 현장실물실험을 통해 낙석운동에너지, 암반의 반발계수, 낙석방지울타리의 흡수에너지 등을 산정하여 절개면 특성별 낙석방지울타리의 설계에 필요한 기초 자료를 제공하고자 하였다. 현장실험을 통해 획득한 낙석방지울타리의 흡수가능에너지는 약 50kJ로 이는 약 0.4톤의 낙석이 10m의 높이에서 낙하할 때 발생하는 에너지와 동일하다.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.192-199
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• 2020

본 연구는 요구되는 전압효율이 83% 이상인 풍량 10,000 ㎥/min급의 장수명 송풍기를 개발하기 위하여 송풍기 침식 현상을 조사하고, 수치해석을 통하여 송풍기 성능과 송풍기 침식을 예측하였다. 송풍기 해석에 주로 많이 사용되는 검증된 상용코드인 ANSYS CFX 13.0을 사용하여 수치해석을 수행하였다. 수치해석에 사용된 조건은 풍량 16,200 ㎥/min, 회전수 893 rpm, 온도 330 ℃이다. 분진의 비중은 3.15이고, 입도는 90㎛~212㎛이며, 양은 265kg/min으로 하였다. 송풍기로 유입되는 분진으로 인한 송풍기의 침식현상을 정확히 해석하기 위하여 수직복원계수의 변화에 따른 침식 현상을 실제 침식현상과 비교하였다. Finne 모델을 적용하여 수치해석을 수행한 결과 평형복원계수는 1, 수직복원계수는 0.1인 경우가 실제 침식현상과 유사하게 나타났다. Duct deflector가 침식에 관하여 미치는 영향을 살펴보기 위하여 Duct deflector가 있는 모델과 없는 모델을 비교하여 침식해석을 수행하였다. 수치해석의 결과, Duct deflector를 설치한 경우 Impeller에서 평균 167% 감소하고, Boss에서는 평균 133% 증가하는 경향으로 나타났다. Dust deflector의 길이에 따라 총 5가지 모델을 생성하고, 이에 대하여 침식 수치해석을 수행하였으며, 길이가 가장 긴 Case 5가 침식성능이 가장 우수한 것으로 나타났다. Case 5의 송풍기 성능은 회전수 880 rpm, 풍량 16,200 ㎥/min일 경우, 전압 691.7 mmAq와 전압효율 83.3%로 나타났다.

• 한국중재학회지:중재연구
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• 제27권1호
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• pp.131-160
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• 2017

When any investment dispute arises, the investor has to exhaust the local remedies available in the host state, and according to the agreement between the parties, the investor is filed to the ICSID arbitral tribunal to seek arbitral awards. At this time, if the arbitral tribunal decides that the investment agreement has been violated, it normally demands the host state to provide financial compensations to the investor for economic loss. According to the rules of the investment agreement, the host state is supposed to fulfill the arbitral awards voluntarily. If it is unwilling to provide financial compensations according to the arbitral awards, however, the investor may ask the domestic court of the host state for the recognition and enforcement of arbitral awards. In addition, if the host state is unwilling to fulfill arbitral awards on account of state immunity, the investor may ask his own country (state of nationality) for diplomatic protection and urge it to demand the fulfillment of arbitral awards. Effectiveness for pecuniary damages, a means to solve problems arising in the enforcement of investment arbitral awards, is found to be rather ineffective. For such cases, this study suggests an alternative to demand either a restitution of property or a corrections of violated measures subject to arbitral awards.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.870-874
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• 2007

Golf ball spin rate after impact with club is created by the contact force, which is greatly influenced by ball and club mass, material, impact speed, and club loft angle. Previous studies showed that the contact force is determined as the resultant force of the reaction forces normal and tangential to the club face at the contact point. The normal force causes the compression and restitution of the ball, and the tangential force creates the spin. Especially, the tangential force takes either positive or negative values as the ball rolls and slides along the club face during impact. Although the positive and negative tangential forces are known to create and reduce the back spin rate, respectively, the mechanism of ball spin creation has not yet been discussed in detail. It is shown in this work that the linear impulse of the tangential force is directly related to generation of back spin rate of golf ball. The linear impulse can be calculated from the tangential force, which depends upon many factors such as ball and club mass, material, impact speed, and club loft angle. In this research, the influence of the contact force between golf club and ball is investigated to analyze the mechanism of impact. For this purpose, the contact force and the contact time at impact between golf club head and ball are computed using FEM.

• 소음진동
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• 제7권4호
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• pp.669-679
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• 1997

This paper deals with a study of striker type impact hammer drill for improving the drilling performance. The study was performed through a numerical simulation of the impact hammer mechanism and an experimental comparison of the numerical simulation results was followed. Optimization of the impact mechanism was also performed. The numerical model of the impact hammer drill takes into account the striker motion and the effects of the pressure in the cylinder as well as the friction acting on the striker. The equation of motion is solved with the pressure equation in the cylinder including the friction force. The friction is considered as a combination of Coulomb friction and viscous damping friction. At the moment of impact, an ideal impact model that uses restitution coefficient is used to calculate the sudden change of the striker motion. The numerically simulated impact force shows a good agreement with the experimental result and thus, the validity of the numerical model is proven. Based upon the proposed model, an optimization was performed to improve the impact force of the hammer drill. The objective function is to maximize the impact force and the used design variables are striker mass, frequency of piston, bit guide mass, cylindrical diameter and dimensions of the mechanism components. Each design variable and some other conditions that are essential to manitain normal operation of the hammer drill are considered as constraints. The optimized result show a remarkable improvement in impact force and an experimental proof was investigated.

• 한국소음진동공학회논문집
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• 제17권11호
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• pp.1127-1132
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• 2007

Golf ball spin rate after impact with club is created by the contact force, which is greatly influenced by ball and club mass, material, impact speed, and club loft angle. Previous studies showed that the contact force is determined as the resultant force of the reaction forces normal and tangential to the club face at the contact point. The normal force causes the compression and restitution of the ball, and the tangential force creates the spin. Especially, the tangential force takes either positive or negative values as the ball rolls and slides along the club face during impact. Although the positive and negative tangential forces are known to create and reduce the back spin rate, respectively, the mechanism of ball spin creation has not yet been discussed in detail. It is shown in this work that the linear impulse of the tangential force is directly related to generation of back spin rate of golf ball. The linear impulse can be calculated from the tangential force, which depends upon many factors such as ball and club mass, material, impact speed, and club loft angle. In this research, the influence of the contact force between golf club and ball is investigated to analyze the mechanism of impact. For this purpose, the contact force and the contact time at impact between golf club head and ball are computed using FEM.

• 센서학회지
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• 제19권2호
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• pp.149-154
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• 2010

Top of the alumina body which is made according to plan has been printed using a screen printer equipment in order to print an electrode pattern. The electrode is connected with the quartz crystal oscillator of the piezoelectricity method which has a piezoelectric characteristic. The pressure contact department has been experimented using three type of the teflon. The teflon is good for pressure delivery vector but it is bad restitution. So we devised the structure which inserts the metal in the teflon. Bottom of the module is connected with the signal processing department which is planned in advance and then has investigated to characteristic. Therefore we have got the best output-voltage and frequency characteristic follows in the pressure.

• 한국기계가공학회지
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• 제7권4호
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• pp.115-120
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• 2008

The fatalities of pedestrian accounted for about 40.0% of all fatalities in Korea (2005 year). In pedestrian involved accident, the most important data to inspect accident is throw distance of pedestrian. The throw distance of pedestrian can be influenced by many variables, such as vehicular frontal shape, vehicular impact speed, the offset of impact point, the height of pedestrian, and road condition. The trajectory of pedestrian after collision can be influenced by vehicular frontal shape classified into sedan type, box type, SUV type and van type. Many studies have been done about pedestrian accident with passenger car model and bus model for simple factors. But the study of pedestrian accident by van type vehicle was much insufficient, and even that the influence of multiple factors such as the offset of impact point was neglected. In this paper, a series of pedestrian kinetic simulation were conducted to inspect relationship between throw distance and multiple factors with using PC-CRASH s/w, a kinetic analysis program for a traffic accident for van type. By based on the simulation results, multi-variate regression was conducted, and regression equation was presented.

• 한국기계가공학회지
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• 제11권2호
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• pp.92-97
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• 2012

In the present the usage of bicycle has increased steeply due to well-being and convenient way of movement. In car to bicycle accident, the throw distance of bicycle is very important factor for estimating collision situation. In this study, simulations and collision tests in actual car to bicycle were executed for obtaining throw distance of bicycle. The simulations were executed by PC-CRASHTM s/w with vehicle of sedan type. Sand bags were used for the behavior of bicyclist instead of dummy and factors considered were vehicle velocity, the crashed angles and part of bicycle to vehicle, and bicycle was adult type. From the results, the throw distances of tire collision of 00 was longer than that of 450 tire crash, and the throw distances of 900 frame crash were longer than those of 450 frame crash. With based on actual crash tests and simulations, restitution coefficient of between vehicle and bicycle was estimated as 0.1. Finally the increaser vehicle velocity the longer the throw distances of bicycle and the simulation results were relatively good agreement to the results of experiment.