• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.1092-1098
• /
• 2004

Today the demand of the optical communication components has been increased. Zirconia Ferrule has become the one of the most important elements because it determines transmission efficiency and quality of information in the optical communication system. Grinding is the major process in the ferrule manufacturing process which require high processing precision. In this reseach, specially designed spindle, chucking system, loading & unloading system and cooling system, as a supporting experimental equipment for development of an Intelligent Coaxial Grinding System (ICGS) for Zirconia Ferrule processing, is developed. We are also analized the adaptability of ICGS in practical use, through the way of evaluation for the performance of the each systems above.

• 한국항만경제학회지
• /
• 제33권1호
• /
• pp.1-10
• /
• 2017

물류센터의 생산성 및 안전도 향상을 위한 기계화 및 자동화가 급속도로 진행되고 있으며, 작업자들의 효율적이고 안전한 작업 지원을 위한 다양한 연구들이 진행되고 있다. 하지만, 집배송차량과 물류센터 간 연결 역할을 하고 있는 하역작업장의 경우는 아직까지도 지게차 위주의 작업이 이루어지고 있다. 또한 지게차와 작업자가 같은 공간에서 함께 작업함에 따라 이로 인한 안전사고도 자주 발생하고 있다. 따라서 본 연구에서는 상하역자업장의 기계화 및 자동화를 통해 생산성과 안전성 향상의 문제를 해결하기 위해 여러 개의 팔레트를 한꺼번에 작업할 수 있는 일괄 하역장비들에 대해 소개하였다. 일괄 하역장비들은 새로운 개념의 하역장비로 적용 시 효율적인 운영을 위해 필요한 적정 장비 대수는 범용 4대, 전용 3대이다. 작업장 면적은 장비크기와 부가공간을 포함하여 범용 $256.28m^2$, 전용 $207.00m^2$가 필요하며 이를 기반으로 작업장 면적 및 일괄 상하역장비를 고려한 상하역작업장을 설계하였다. 또한 NPV, IRR, PBT 등 경제성 분석을 실시하였으며 주요 변수에 대한 민감도 분석을 수행하였다.

• 산업기술연구
• /
• 제37권1호
• /
• pp.5-11
• /
• 2017

The purpose of this research is to propose an efficient loop line operation plan for customer transportation in a new theme park. Based on the expected customer arrivals, customer loading/unloading methods, and scheduled/non-scheduled departure schemes, movement time between stations etc., we have performed indepth analyses and derived the best optimal policy. Our results show that, over all, the operation with separate loading/unloading doors and scheduled departure is preferred to the other options. We then derived the optimal number of trains and cars meeting minimal customer unsatisfaction with low cost for each season.

• Journal of Biosystems Engineering
• /
• 제13권3호
• /
• pp.44-51
• /
• 1988

The objective of this study is to develop a grain handling system for loading, unloading and transporting of rough rice stored at the in-bin drying and storage (IBDS) developed by the Korea Advanced Institute of Science and Technology(KAIST). A mechanized Fain handling system consisted of a portable auger and a gate was developed and tested. The test results can be summarized as the following: 1) The loading capacity of the handling system developed is $16.2m^3/h$ (8.3 ton/h) for the Indica type rice and $13.0m^3/h$(7.3 ton/h) for the Japonica type. It is greater than that of manual handling as much as 2.5 - 2.7 times. 2) The unloading capacity of the handling system developed is $16.0m^3/h$(8.2 ton/h) for the Indica type rice and $12.6m^3/h$(7.0 ton/h) for the Japonica type. It is greater than that of the manual as much as 4.7 - 5.5 times. 3) For 3-ton capacity of the storage, the loading and unloading can be performed for 20 and 30 minutes by one man operation of equipment. while 60 and 120 minute for the manual of 2 men, respectively. 4) The volumetric efficiency of the system developed is 0.42 - 0.54 and the power efficiency is 4.0 - 4.4. 5) The break-even quantity of the handling system developed is about 38.6 ton($68.7m^3$) of rough rice and the initial investment for the system would be returned within five years for the most owners of the KAIST IBDS system.

• 대한조선학회논문집
• /
• 제33권1호
• /
• pp.124-134
• /
• 1996

본 연구에서는 LNG선의 화물하역 중 비상 상황시 펌프를 정지시키고 선박측의 긴급 차단 밸브 및 육상측의 정지 밸브를 폐쇄시킬 때, 관내 유체의 급격한 속도변화에 의하여 발생하는 비정상 유동 상태인 서지(Surge)현상의 원인을 고찰하고, 이 때 발생하는 상승압력과 유량의 변화를 계산하였다. 해석 결과에 의하면 서지현상에 의한 과도한 압력상승은 선박측의 긴급 차단 밸브 및 육상측의 정지 밸브의 종류와 이들의 폐쇄 시간, 그리고 배관 배치에 크게 영향을 받음을 알 수 있었다.

• 한국항만학회지
• /
• 제12권1호
• /
• pp.113-118
• /
• 1998

The Container crane is mainly used in the harbor. But in spite of this wide use, it is a fact that there are still areas for automation, concerning the operator and the control system. If the encoding function is enhanced, then control effect can be increased to some extent. Since the distance from the hoist to the trolley cam be measured, the moving distance from the loading and unloading can be minimized. If this is applied to the real system, hazard elements can be eliminated and in given time since more unloading can be done, congestion can be reduced.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.519-524
• /
• 2003

In this paper we discuss the dynamic characteristics of the in-arm type hydropneumatic suspension unit(ISU). For this, two accurate models are introduced. The first one is the Benedict-Webb-Rubin equation which is adopted for the spring behavior of a real gas. This equation is applicable for the high pressure of the nitrogen gas which acts as a spring in ISU system. The second one describes the behavior of a damper, which is divided into four parts - jounce-loading, jounce-unloading, rebound-loading and rebound-unloading. This approach gives a good approximation of the real damper system. For the comparison purpose, the numerical results of the dynamic behavior of ISU system using a real gas and an ideal gas are given in the paper.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1688-1692
• /
• 2003

The automatic Landing system is used for the automatic functions of automatic transfer crane in the automated container terminal. It confirms and adjusts the alignment and pose between spreader and container and accomplishes the automatic loading/unloading job of containers in yard. Specially, it is required in the automated container terminal and is well adapted under the coarse external environments. This system used the laser sensors to recognize the alignment between spreader and container. In this paper the algorithm of recognition of the alignment and pose is presented and the result of its simulation is shown.

• 대한산업공학회지
• /
• 제21권2호
• /
• pp.153-165
• /
• 1995

Many closed queueing network models have been used as an effective tool to make a preliminary design of FMS. Although a loading/unloading function is an important factor to effect the utilization and throughput of FMS as well as a transfer function and a processing function, the Solberg's model did not clarify the loading/unloading function. In this paper, we propose a closed queueing network model for analyzing a flexible manufacturing system that consists of a load/unload station, a material handling system and a group of workstations for processing jobs, and define the expected utilization and the expected throughput of the FMS. As applications of the proposed model, the cases of a material handling system consisting of a conveyor and the FMS including an inspection station are also formulated.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
• /
• pp.489-497
• /
• 2000

Since Chinese cabbages weigh 3 to 5kgf and are big in size at the time of harvest, handling operations such as harvesting, loading and unloading including transportation require the highest labor demand among all other cultivation processes. Recently, though several cabbage harvesters were developed in Japan and Europe, those harvesters were not suitable for Chinese cabbages cultivated in Korea because of the size and shape. The cabbage harvester is almost meaningless without any proper cabbage piling and pallet unloading mechanism. Most harvesters developed so far adopted a sort of slide and free falling way in collecting cabbages into the pallet. Three or four labors are usually required for cleaning incoming cabbages and loading those in the pallet. Because of the required time for piling cabbages without severe damage and the required space capacity to carry empty and loaded pallets, harvesting speed should be adjusted in accordance with time required for consecutive operations. Up to now, any automatic or semi-automatic collecting device has not been developed in the world to pile cabbages on the layer one by one into the pallet in the ordered way with little damage and to unload pallet from the harvester continuously during the harvest process. To compromise system expenses and function, Semi-automatic cabbage piling and pallet unloading mechanism was devised and it required one labor. The foldable mesh pallet with a size of 1050mm x 1050mm x 1000mm and holding capacity of around 70 cabbages was utilized. The prototype for piling and unloading mechanism was composed of three parts such as feeding device, automatic piling device with retractable bellows, and pallet unloading device. Prior to developing the prototype, the geometric properties and the amount of the damage of the cabbage caused during the piling operation were investigated. Considering the height of the pallet, a series of cabbage carrying plates were mounted to the bracket chain to lift and to carry cabbages to the loading device. Indoor laboratory experiments showed that the cabbage carrying chain conveyor worked successfully. Considering the conveying speed 0.46m/sec of the pull up belt from the cabbages on the ground, the speed of cabbage carrying chain conveyor worked property in the range of 0.26m/sec to 0.36m/sec. The system allowed the operator to modify the position of cabbage slightly. Overall system worked successfully resulting into almost same capacity without severe damage to the cabbage as human did.