• Journal of Korea Port Economic Association
• /
• v.24 no.2
• /
• pp.335-350
• /
• 2008

This paper analyzes the effects of port size on port tariff using the data for world major sixteen container ports. Some previous studies show that demand for port services have significant effects on port tariff, but we cannot find studies analyzing the correlation between the supply variables and the port tariff. In this paper, we used the five supply variables, which are the number of gantry crane, the number of berth, the quay length, the terminal area and the storage capacity for containers. The panel regression results are as follows. Port tariff generally decreases as port size increases, which shows that port tariff is explained by the economic theory. However, increase of port size, in some cases, does not reduce port tariffs, which may be due to monopolistic characteristics of port. This paper also shows that both demand and supply factors affect port tariff, but that demand factors have more consistent effect on port tariff than supply factors.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.1
• /
• pp.59-69
• /
• 2018

The up-to-date business environment for Korean manufacturers is very complex and rapidly changing. Especially, the companies have faced with various changes derived from small quantity batch production, diversification of customer demands, and short life cycles of products. Consequently, the Korean manufacturing companies are in need of more efficient production planning and scheduling techniques. In this paper, the research trend of scheduling techniques is investigated to provide relevant information to researchers in this field. Furthermore, some implications for future researches are presented regarding literatures published in Korea over the last 10 years. This paper presents an entire investigation into Korean research works on scheduling (2,569 papers) that are published from 2007 to 2016. Especially, detailed analysis was carried out in the following three industry : 1) semiconductor, 2) shipbuilding and 3) automobile. In this paper, approaches to scheduling presented in the literature are categorized into the following three categories : 1) application, 2) algorithm, and 3) simulation modeling. First, in the semiconductor industry, scheduling techniques related to semiconductor cleaning processes, photolithography processes, chemical processes, transport and transport equipment have been found to be dominant. Second, the shipbuilding industry is focused on assembly processes, transporter, crane and various existing production management system. On the other hand, the scheduling research of the automobile industry is mainly focused on the vehicle movement routing and procurement supply-chain planning algorithm in terms of logistics. The conclusion of this study are expected to provide many implications for various types of academic and practical follow-up studies related to scheduling in consideration of main characteristics of semiconductor, shipbuilding and automobile industries.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1906-1909
• /
• 2005

This paper presents the acceleration optimization of a high-speed LCD (Liquid Crystal Display) transfer system for the minimization of vibration. To reduce vibration is one of key requirements for the dynamic control of a high-speed LCD transfer system. In this paper, the concept of finite jerk (the first derivative of acceleration) has been introduced for realizing input acceleration. The profile of finite jerk has been optimized using a genetic algorithm so that vibration effect can be minimized. In order to incorporate a genetic algorithm, the dynamic model of a LCD transfer system which is realized by using the $ADAMS^{(R){$ software has been linked to the simulation system constructed by the $MATLAB^{(R)}$. The simulation results illustrated that the duration of finite jerk can be optimized so as to minimize the magnitude of vibration. It has been also shown that the acceleration optimization with finite jerk can make the high-speed motion of a LCD transfer system result in low vibration, compared with the conventional motion control with trapezoidal velocity profile.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.2
• /
• pp.77-85
• /
• 2010

Recently, As increasing cleanroom size, Stocker system is trending the large size and long distance for LCD material transfer system In order to rise a rate of production, the manufacturer are on the decrease of total tact time with Stocker system And the manufacturer are requested to high speed of next generation Stocker system Also manufacturers for the high oil prices through energy-saving conservation to minimize plant operating costs are required. Therefore, this paper propose optimal design of high efficiency Contactless Power Supply(CPS) system about high speed and energy savings of next generation Stocker system This paper proposes CPS system is applied in the long distance and straight section with Stocker system for energy savings. The test results of input!output characteristic and efficiency of CPS system on operating pattern of Stocker system were analyzed, and proved the applicability on commercial use.

• Journal of Navigation and Port Research
• /
• v.33 no.5
• /
• pp.323-330
• /
• 2009

We have been developing an underwater robot for harbour construction using a parallel mechanism The robot is attached to the rope of a crane, which curries a large stone into the undersea The robot's yaw and pitch are controlled by hydraulic cylinders but its roll is uncontrollable. We mount propellers in both side of the robot to generate the roll motion This paper studies on the control for the roll motion of a underwater robot. A gyro-sensor is used to measure the angle in a roll motion We develop the dynamic model to describe the robot's roll motion by a second order non-linear system and identify the model parameters by recursive least square and adaptive identifier. PD control, recursive model based control and adaptive model based control are applied with the dynamic model which computes the control input to compensate disturbances. This paper introduces the underwater robot system and presents the simulated and experimental results of the proposed controller.

• Journal of Navigation and Port Research
• /
• v.44 no.3
• /
• pp.227-234
• /
• 2020

One of the most important operational goals in container terminals is to maximize the quay side productivity by minimizing the turnaround times of the vessels, for which the operations of the quay cranes (QC) to load/unload containers onto/from the vessels should be conducted efficiently without delays. This paper suggests using a policy-based dispatching method for YTs (Yard Tractor) that deliver containers between QCs and the storage yard. The goal of using such a dispatching policy is to maximize the efficiency of the YT operation and accordingly to minimize the QC delays because of late arrivals of the YTs. In particular, in this paper, we modified the previously proposed policy for its application to real container terminal and verified the effect through simulation experiments using real terminal data.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.2
• /
• pp.191-199
• /
• 2007

This paper presents a closing method for a cable-stayed bridge erected by the free cantilever method to produce the initial equilibrium configuration at the final construction stage. To realize the initial equilibrium condition in cable-stayed bridge by the cantilever method, compatibility conditions for vertical displacements, rotational angles, and axial displacements at the closing section of both side girders should be satisfied. In this paper, it was shown that it can be accomplished by using some applicable loads during construction such as the pull-up force of the derrick crane, some cable tension forces, and jacking force at the pylon. The proposed method was applied to a construction stage analysis of a sample bridge to demonstrate its validity, and it was acknowledged that the tower was considerably affected by the compatibility condition for axial displacement in the closing step.

• Fashion & Textile Research Journal
• /
• v.24 no.1
• /
• pp.95-107
• /
• 2022

In reality, the distinction between the Korean traditional culture and the cultures of other countries is at a delicate boundary. Additionally in the wake of the recent socio-cultural confrontation between Korea and China, it has become necessary to establish the foundation and area of Korean traditional culture and to actively utilize the importance of improving awareness of Korean traditional culture. To reorganize the reckless use of the gold foil pattern shown in the rental hanbok, data on the museum's collection of gold leaf patterns were collected and analyzed. Based on the gold foil, Gilsang characters such as Phoenix pattern, Crane pattern, Bat pattern, Flower pattern, Fruit pattern and recovery advice were extracted through references. The traditional gold foil pattern was reconstructed and relocated to design the gold leaf patch. Based on the collection and analysis of the museum's relics, the Wonsam & Daedae, Dangeui, Sranchima, Sagyusam, Jeonbok, Bokgun, and Daenggi were produced. Therefore, we present the possibility of producing gold foil and modern methods for producing gold foil using laser cutting techniques that can express refinement and complexity well, and gold foil thermal transfer paper with retouchable effects. Additionally, we would like to reflect upon the practicality and the convenience to modern people by considering the complexity and hassle of the traditional gold foil production process, and the disadvantages of processes that require relatively longer time. It intends to help revitalize the market of Korean traditional clothing and fashion products.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.19 no.2
• /
• pp.84-91
• /
• 2015

In this paper, to overcome disadvantages of existing lining boards, the parametric studies to evaluate safety and verify performance of newly suggested lining boards was performed. Since the calculated stresses of steel plates are lower than the allowable stress for considered all analytical variables, end reinforcement locations, and crane rail loads, it can be concluded that the suggested lining board is structurally safe. Where, "$3,000{\times}2,000{\times}6t$" was select to be optimized cross-section and the reinforcement from the end to 200mm to the internal direction looks like the best case. In addition, the suggested lining board is economical since the steel amount per unit area compared to existing lining board is reduced by 36% and it can apply to the lining structural system of subway and underpass since construction speed is past due to the less installation number of lining boards.

• Journal of Navigation and Port Research
• /
• v.31 no.8
• /
• pp.717-723
• /
• 2007

In recent years, the transportation sector has been undergoing very rapid and multifarious changes due to the M&A, alliances between shipping companies, introduction of larger container ship as it cost reduction measure and the application of integrated logistics to satisfy the needs of customers. Therefore, container terminal is required adequate terminal facilities, sufficient channel depth, efficient handling and low cost of port fees and dues. The purpose of this paper is for functional assessment of efficient container terminal. Firstly, the container operating process information about yard equipment and chassis is extracted through the analysis of practical daily work report of container terminal. Also, the formulae of skill factor and troubles of operator on transfer crane are defined. Lastly, container handling simulation model which consideration of skill factor and trouble of operator is proposed by Petri network model.