• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2011.10a
• /
• pp.97-98
• /
• 2011

This paper is about the study of a new exo-skeleton device applying a gravity compensator. The exo-skeleton devices is to reduce the external torque applied to the human body joint for the purpose of helping the disabled, reducing heavy payload for industry workers or military soldiers. Most of the exoskeleton devices are actuated by the motors, but motors are limited in energy such that a short durability is always a big problem. In this paper, an exoskeleton device using a new gravity compensator based on a torsion bar is proposed to reduce the torque load applied to human body joints. The exoskeleton device is designed for the lower body of human. Analyses on the torsion bar spring and link of the exoskeleton device using FEM method were performed. To reduce the applied torque to the human joint, a torsion bar gravity compensator is applied to the exoskeleton. The effect of the torsion bar compensator for the exoskeleton device was verified through load test using developed test equipment.

• Korean Security Journal
• /
• no.41
• /
• pp.37-66
• /
• 2014

In recent years, with the development of computers and electronics, electronics and communication technology in a growing and each part is dependent on the cross-referencing makes all electronic equipment is obsolete due to direct or indirect damage EMP. Korea and the impending standoff North Korea has a considerable level of technologies related to the EMP, EMP weapons you already have or in a few years, the development of EMP weapons will complete. North Korea launched a long-range missile and conducted a nuclear test on several occasions immediately after, when I saw the high-altitude nuclear blackmail has been strengthening the outright offensive nuclear EMP attacks at any time and practical significance for the EMP will need offensive skills would improve. At this point you can predict the damage situation of Korea's security reality that satisfy the need, more than anything else to build a protective system of the EMP. The scale of the damage that unforeseen but significant military damage and socio-economic damage and fatalities when I looked into the situation which started out as a satellite communications systems and equipment to attack military and security systems and transportation, finance, national emergency system, such as the damage elsewhere. In General, there is no direct casualties reported, but EMP medical devices that rely on lethal damage to people who can show up. In addition, the State power system failure due to a power supply interruption would not have thought the damage would bring State highly dependent on domestic power generation of nuclear plants is a serious nuclear power plant accident in the event of a blackout phenomenon can lead to the plant's internal problems should see a forecast. First of all, a special expert Committee of the EMP, the demand for protective facilities and equipment and conduct an investigation, he takes fits into your budget is under strict criteria by configuring the contractors should be sifting through. He then created the Agency for verification of performance EMP protection after you have verified the performance of maintenance, maintenance, safety and security management, design and construction company organized and systematic process Guard facilities or secret communications equipment and perfect for the EMP, such as protective equipment maneuver system should take.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.5
• /
• pp.649-657
• /
• 2018

It is essential that weapons which are mounted on aircraft need to prove its reliability and safety during its developments. A guided missile should have high reliability and safety throughout various tests which are including ground tests, captive flight tests, detailed technical tests and operational tests. In these various tests, it is vital that software of each component in the guided missile should be easily updated in order to correct algorithms or errors. In this paper, we propose a software update technique based on MDTP(mass data transfer protocol) which are defined in MIL-STD-1760. The proposed techniques have the following advantages: First, software of each unit in a weapon can be updated through a test equipment without disassemble a guided missile. Second, development periods for a software update can be reduced by reusing MDTP. Third, we can easily maintenance of the software because it is based on standard. We proved its efficiency and validity through experiments. Therefore, the proposed technique should be effectively utilized for software update of a weapon mounted on an aircraft during development processes.

• Journal of Korean Society for Quality Management
• /
• v.48 no.3
• /
• pp.395-408
• /
• 2020

Purpose: This study was performed for advancement of aviation security equipments certification system. Methods: We investigated aviation security equipments certification-related registrations and the latest research trends of explosive detection technologies. Based on the literature studies, we draw the critical issues of the aviation security equipment certification system and suggested improvement direction. Results: We found some inaccuracies of the definition of explosive trace detection equipments, accreditation review committee, and performance evaluation test method. These problems should be modified to suit being practical. Conclusion: The present results would be useful for basic data for modifying aviation security equipments certification systems.

• Journal of Advanced Navigation Technology
• /
• v.24 no.4
• /
• pp.261-266
• /
• 2020

When a KW-class power control unit is installed in an aircraft installation, a heat dissipation design for a large amount of heat generated during power conversion should be considered. Failure to provide adequate heat dissipation can lead to equipment malfunction and fire, which can be a fatal factor in aviation operations. This paper describes the heat dissipation design of a KW-class power control unit installed in aircraft installation. The design and manufacturing test were conducted through computerized analysis, and the analysis model was corrected by confirming the rapid heat generation phenomenon of the heating element due to high power control. After the model revision, the design was improved, and the high-temperature operation test of the US military standard MIL-STD-810G was performed to confirm the feasibility of the improved design.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.4
• /
• pp.164-172
• /
• 2020

The fuel oil/heat exchanger installed in military aircraft is a device that cools the lubricant oil supplied to other devices, such as an AMAD, and a hydraulic pump using the low temperature of the fuel is cracked at the AMAD lubricant inlet port. If a crack in the heat exchanger occurs, the lubricant oil supplied to other equipment is not cooled. Therefore, the flight can no longer be performed. In this study, non-destructive inspection and microscopic examination of the fracture surface of the oil port were performed to analyze the crack tendency. The oil pipe connected to the oil port is a titanium pipe, which is fastened with over torque and has been identified as the leading cause of heat exchanger oil port cracks. In addition, it was verified as the main reason for cracking by finite element analysis. The material and diameter of the pipe were changed to improve this defect, and the applied torque was adjusted. In addition, the bending value of the pipe was adjusted to minimize the fatigue accumulation due to pulsating pressure. As a result, no cracks occurred on the heat exchanger via the ground test after the installation of an improved pipe under the same conditions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1995.10a
• /
• pp.296-304
• /
• 1995

환경시험의 일부인 진동시험은 그 결과를 가지고 장비가 실제 운용하기 전에 진동에 대한 내구성이 있는가를 판단할 수 있는 단 하나의 방법이다. 이런 진동시험을 성공적으로 이끌어 정확한 결론에 도달하기 위해서는 아래 두 가지 문제에 대한 해결이 필수적이라고 생각한다. 첫번째는 '실제 상황을 정확히 반영할 수 있는 진동시험수준의 결정이다.' 진동시험수준이 적절하지 못하면 전체적으로나 부분적으로 과대진동시험(Overtest)을 실시하거나, 과소진동시험(Undertest)을 실시할 수 밖에 없고, 이에 따른 결과도 신뢰도가 떨어진다. 예를 들어, 과대진동시험으로 시험장비가 고장나거나, 과소진동시험으로 시험장비에 이상이 없다고 해서 실제 상황에서 이 장비가 진동에 대하여 만족할 만한 내구성을 갖는다고 누구도 말할 수 없기 때문이다. 두번째는 '정해진 진동시험수준을 진동시험기로부터 시험장비에 얼마나 정확히 전달할 수 있는가?'라는 문제이다. 실제로 원하는 진동시험수준을 한치의 오차없이 정확히 시험장비에 가하는 것은 거의 불가능하다. 특히 시험장비가 대형화 되면 될수록 문제는 더 심각하다. 결론적으로 위에 지적한 두가지 문제의 해결이 성공적인 진동시험의 열쇠이며, 또한 시험결과에 대한 신뢰성을 보장받을 수 있는 길이기 때문이다. 이번 논문에서 다루고자 하는 것은 두번째 문제인 진동시험수준의 정확한 전달을 위하여 진동시험기와 시험장비 사이를 연결해 주는 진동시험치구(Test Fixture) 개발에 관한 것이다. 실제 개발한 치구는 미군사규격(Military-Standard)과 보잉사 규격(Boeing specification) 그리고 샌디아사 규격(Sandia Corporation Standard)에 근거하여 분류하는 분류기준표에서 치구 중 가장 큰 부류(500 pounds 이상)에 속는 것으로, 현재 우리나라에서 보유하고 있는 것 중에 용량이 가장 큰 진동시험기에서 진동시험을 준비하고 있는, 체계에 전원을 공급하는 대형장비의 치구이다. 또한 실 진동시험을 실시하기 전의 모달시험과 예비시험 그리고 실 시험결과를 기술하므로써 제작된 치구의 실험적 평가를 하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.5
• /
• pp.443-450
• /
• 2020

This paper reports a design improvement study to solve the stoppage phenomenon caused by the launch-support device applied to K105A1. The K105A1 is a weapon system equipped with an old 105 mm towed howitzer in a wheeled vehicle, which provides superior maneuverability compared to track equipment. The launch support device serves to withstand fire impact and load. In this way, this device is fixed firmly to the ground in preparation for the shooting mission and is responsible for the critical performance, such as fixing the position of the vehicle. On the other hand, during the field test, a temporary stoppage of the launch support occurred, which caused a problem of not being fixed to the ground. To solve this problem, the cause of failure was analyzed by a replay test and parts inspection. In addition, the operating concept, method, and design were analyzed to derive the cause and solve the problem by changing the parts design. Finally, the performance and firing missions were performed normally by applying the changed design to K105A1. The performance stability and reliability of the launch support device were confirmed, which are expected to be of great assistance in the development of military equipment in the future.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.383-388
• /
• 2020

This study aimed to identify the influence of the power components of the ammunition vehicle on the maximum speed. The maximum speeds of the engine and transmission changes were 3% and 1.7%, respectively. In the case of strong tension based on the track tension, the decrease was 4.6%. A 1.5% increase was obtained when the tension was weak. An examination of the maximum speed by dividing the track tension into six sections revealed the maximum speed to be highest when it was maintained below the middle. Experiments were performed by varying the orbital tension on both sides of the equipment. The maximum speed of the machine was affected by a large part of the tension. The maximum speed test was conducted by adjusting the tension at the driving test site. The results showed that when the tension was strong, the speed was 16.7% higher than the standard requirement. The speed was 28.3% at low tension. The influence of the maximum speed on the track tension was confirmed; the effect was greater than replacing the large parts.

• Journal of Korean Physical Therapy Science
• /
• v.26 no.3
• /
• pp.23-36
• /
• 2019

Background: The purpose of this study was to investigate the effect of Plank exercise on unstable support surfaces on flexibility, abdominal muscle thickness and pain in patients with chronic back pain. Design: Randomized controlled trial. Methods: This study was performed on 16 patients with chronic back pain of ◯◯ military unit. Sixteen subjects were randomly assigned into two groups, an upper extremity trainer group (group I, n=8) and a lower extremity trainer group (group II, n=8). The subjects in group I carried out Flank exercise applying the stability trainer to their upper extremities and ones in group II carried out the same exercise applying the stability trainer to their lower extremities for 4 weeks. In order to ascertain the difference between two groups, flexibility, abdominal muscle thickness and pain were measured before and after the exercise. The flexibility was measured by sit and reach test, the thickness of the abdominal muscle was measured by using ultrasonic imaging equipment, and the pain was measured by the visual analogue scale. A paired t-test was utilized to compare changes in pain, abdominal muscle thickness and flexibility before and after flank exercise on unstable support surfaces. Analysis of Covariance (ANCOVA) was performed for ascertaining the significant differences between groups. The significance level was set by α=.05. Results: 1) The flexibilities of two groups were increased after the exercise (p<0.05). 2) In both groups, the thicknesses of rectus abdominis, external oblique abdominis, internal oblique abdominis, and transverse abdominis were all increased after the exercise (p<0.05). 3) The pains in both groups were decreased after the exercise (p<0.05). 4) In the comparisons of two groups, there were no differences in the flexibility, thickness of external oblique abdominis, internal oblique abdominis and transverse abdominis and pain (p>0.05). Whereas only thickness of Rectus abdominis was larger in the group I than in the group II (p<0.05). Conclusion: Plank exercise on the unstable support surface for 4 weeks resulted in increased flexibility, abdominal muscle thickness and pain reduction in patients with chronic back pain. Therefore, it is considered that performing flank exercise on the unstable supporting surface is suitable for the reduction of the pain in patients with chronic back pain. However, in this study, it is considered that continuous and diverse studies are needed because there was not a large difference between the groups when the upper or lower limbs are provided unstable support surfaces.