• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.134-142
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• 2003

We present an ATM switch architectures based on the multistage interconnection network(MIN) for the efficient multicast traffic control. Many of these applications require multicast connections as well as point-to-point connections. Muiticast connection in which the same message is delivered from a source to arbitrary number of destinations is fundamental in the areas such as teleconferencing, VOD(video on demand), distributed data processing, etc. In designing the multicast ATM switches to support those services, we should consider the fairness(impartiality) and priority control, in addition to the overflow problem, cell processing with large number of copies, and the blocking problem. In particular, the fairness problem which is to distribute the incoming cells to input ports smoothly is occurred when a cell with the large copy number enters upper input port. In this case, the upper input port sends before the lower input port because of the calculating method of running sum, and therefore cell arrived into lower input port Is delayed to next cycle to be sent and transmission delay time becomes longer. In this paper, we propose the cell splitting and group splitting algorithm, and also the fairness scheme on the basis of the nonblocking characteristics for issuing appropriate copy number depending on the number of Input cell in demand. We evaluate the performance of the proposed schemes in terms of the throughput, cell loss rate and cell delay.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.127-132
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• 2004

Most q the domestic container terminals are inferior to throughput q container. The reason why they have the difference between the handling capacity q planed quay and its real. By putting into quay handling equipment, the productivity of quay can be improved, waiting rate q the ship can be lowed. This paper suggests more resonable terminal construction, throughout comparing with previous construction way, improved handling capacity and the economical efficiency of equipment costs, labor costs, construction costs, operation costs on change of terminal size by adding the equipment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.429-436
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• 2011

The G-PON is an efficient solution to implement the FTTH and have GEM frame to accomodate various protocols like Ethernet frames, IP packets, and TDM signals. Above all, the Ethernet is one of the most widely used 2nd layer protocol in the campus, the subscriber access, and the carrier service. So G-PON system has to provide an Ethernet interface with top priority. In this paper, we implement a gigabit Ethernet adapter based on Ethernet over GEM in the ITU-T G.984.3 to accommodate Ethernet protocol in the G-PON TC chip. The adapter maps each Ethernet frame to a single or multiple GEM frames and has several functions including generation of the GEM header, encapsulation of frames and the SAR. In particular, the adapter have converter (LUT) MAC address to port-ID which is a key to identify logical connections though it is not defined in specification but important. We implement the adapter with a FPGA and verify the functions of segmentation and reassembling, MAC address learning, and throughput with the logic analyzer and the Ethernet analyzer.

• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.221-226
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• 2005

This paper provides a method to implement IT system for supply chain management problem The fundamental scheduling issues that arise in the pickup delivery system are optimizing the system with the minimum cost, the maximum throughput and the service level. This study is concerned with the development of the customer responsive pickup-delivery system based on e-logistics and demand chain management. Through this study, the pickup-delivery problem of the vehicle using the GIS PDP and GUI- type computer programs are formulated. The computational results show that the proposed method is very effective on a set of test problems.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.653-658
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• 2008

The demand of international intermodal transportation is continuously increasing in accordance with a changing environment on international logistics, Under this circumstance, the Sea&Air intermodal transportation, combined by sea-based and air-based transport, has a potential growth in the future. After analyzing routes for Origin/Destination and implementing portfolio analysis, finally, this research aims to propose alternatives to create additional customers(or cargoes) for the Sea&Air transport. As a result of the analyses, China appeared to be a major customer of the Sea&Air transport in Korea because some of the Chinese areas - i.e. Qingdao, Shanghai, Weihai and Yantai - account for 88.1% of the total throughput. In general, this indicates that it would be more efficient to establish specific strategies targeting those major areas. Excluding the four areas, most of the other area, have much less demands and are relatively unstable. The demands, growth rates and market shares especially in Vladivostok, Dandong and Tianjinxingang are on the decrease, and therefore, stable strategies seems to be appropriate than aggressive strategies for these areas.

• Journal of Internet Computing and Services
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• v.3 no.3
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• pp.87-93
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• 2002

A complex network and a parallel computer are made up of interconnected switching units. The role of a switching unit is to set up a connection between an input port and an output port, according to the routing information. We proposed our switching network with a remodeled architecture is a newly modified Banyan network with eight input and output ports. We have analysed the maximum throughput of the revised switch. Our analyses have shown that under the uniform random traffic load, the FIFO discipline is limited to 70%, The switching system consists of an input control unit, a switch unit and an output control unit. Therefore the result of the analyses shows that the results of the networking simulation with the new switch are feasible and if we adopt the new architecture of the revised model of the Banyan switch, the hardware complexity can be reduced. The FIFO discipline has increased by about 11% when we compare the switching system with the input buffer system. We have designed and verified the switching system in VHDL using Max＋plusII. We also designed our test environment including micro computers, the base station, and the proposed architecture. We proposed a new architecture of the Banyan switch for BISDN networks and parallel computers.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.51.1-51.1
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• 2014

DOTIFS is a new multi-object Integral Field Spectrograph (IFS) being designed and fabricated by the Inter-University Center for Astronomy and Astrophysics, Pune, India, (IUCAA) for the Cassegrain side port of the 3.6m Devasthal Optical Telescope (DOT). The telescope is constructed by the Aryabhatta Research Institute of Observational Sciences, Nainital (ARIES). Its main scientific objectives are the physics and kinematics of the ionized gas, star formation and H II regions in nearby galaxies. It is a novel instrument in terms of multi-IFU, built in deployment system, and high throughput. It consists of one magnifier, 16 integral field units (IFUs), and 8 spectrographs. Each IFU is comprised of a microlens array and 144 optical fibers, and has $7.4^{\prime\prime}{\times}8.7^{\prime\prime}$ field of view with 144 spaxel elements with a sampling of 0.8" hexagonal aperture. The IFUs can be deployed on the telescope side port over an 8' diameter focal plane by x-y actuators. 8 Identical, all refractive, dedicated fiber spectrographs will produce 2,304 R~1800 spectra over 370-740nm wavelength range with single exposure. Currently, conceptual and baseline design review had been done, and is in the critical design phase with a review planned for later this year. Some of the components have already arrived. The instrument will see its first light in 2015.

• Journal of Korean Port Research
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• v.2 no.1
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• pp.29-73
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• 1988

Since the middle of 1950's when sea transportation service by container ship was established, containerization has been rapidly spread over the world with realization of intermodalism, and becomes an index of economy growth of a country. Our country has established Pusan Container Terminal at Pusan harbour in 1978 in step with worldwide trend of containerization, and is constructing New Container Terminal at Pusan outharbour which will be completed in 1990. This paper aims to make a quantitative analysis of the Pusan Container Terminal system through the computer simulation, especially focusing on its subsystems such as ship stevedoring system, storage system and transfer system. First, the capacity of various subsystems are evaluated and it is checked whether the current operation is being performed effectively through the computer simulation. Secondly, the suggestion is presented to improve the operation by considering the throughput that Pusan Container Terminal will have to accept until 1990, when New Container Terminal will be completed. The results are as follows ; 1) As the inefficiency is due to the imbalance between various subsystems at Pusan Container Terminal on the basis of about 1.2 million TEU of container traffic, transfer equipment level must be up to 33% for transfer crane, and free period must be reduced into 4/5 days for export/import. 2) On the basis of about 1.4 million TEU of container traffic, transfer equipment level must be up to $12\%$ for gantry crane, $11\%$ for straddle carrier and $66\%$ for transfer crane, and free period must be reduced into 3/4 days for export/import. 3) On the basis of about 1.7 million TEU of container traffic, transfer equipment level must be up to $25\%$ for gantry crane, $28\%$ for straddle carrier and $100\%$ for transfer crane, and free period must be reduced into 3/4 days for export/import. 4) On the basis of about 2 million TEU of container traffic, transfer equipment level must be up to $25\%$ for gantry crane, $30\%$ for straddle carrier and $110\%$ for transfer crane, and free period must be reduced into 2/3 days for export/import, and it is necessary to enlarge storage yard.

• Journal of Korea Port Economic Association
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• v.26 no.4
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• pp.219-246
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• 2010

Countries around the world are propelling policies and strategies to strengthen the competitiveness of their own ports as they recognize the roles and importance of the ports in the international trade and logistics. The main objective of this study is to compare efficiencies of major container ports and analyze the factors that affect the efficiencies in the three regions of East Asia, Europe, and North America, which cover most of world container shipping. We employ DEA models in analyzing the efficiencies of 45 container ports using 5 input and 2 output variables. We also carry out regression analyses to estimate the impacts of each factor on the throughput (TEU), overall technical efficiency (OTE), pure technical efficiency (PTE), and scale efficiency (SE). The analysis results show that East Asian ports, despite being smaller in average size, make greater output and achieve higher technical and scale efficiencies than European or North American ports.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.165-171
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• 2006

The appearance of over 10,000 TEU containerships (so called Mega-containerships) is determined. In order to operate these ships effectively, the number of these calling ports will diminish, and then feeder ships will transport cargoes from the hub-ports where mega-containerships call to the destination ports. In the hub-ports, handling containers for mega-containerships become huger, thus it is important for terminals to deal with cargo handling as soon as possible. However, the present terminal layout might have the limitation of maximum throughput per time unit. And then the transit time at the ports become longer. Therefore, we investigate the effect on some different terminal layouts with new alternatives. Actually, we discuss the ship-to-berth allocation at some adjacent berths for mega-containerships on three types of terminal layouts. First one is the conventional type consisted by some linear berths, most container terminals in the world are normally this type. Second one is the indented type consisted by linear berths and indented berths which we can handle from both sides of mega-containership simultaneously. Third one is the floating type consisted by linear berths and the floating berth. On this type, mega-containerships can moor between linear and floating berths. The merits of this type are that we can also handle from both sides of mega-containerships simultaneously, and ships can go through between linear berth and floating berths. Thus it is easier for ships to moor and leave berths. Under such assumptions, we examine the numerical experiments. In most cases, the total service times on the indented type are the longest among three types, these on the floating type are the next longer. Those reasons are that these layouts have the differences of berth occupancy obtained by the time and space axes, and whether the precedence constraints of ship service order needs or not.