• Journal of information and communication convergence engineering
• /
• v.17 no.4
• /
• pp.246-254
• /
• 2019

This paper proposes a solution to the problem of finding a subgraph for a given instance of many terminals on a Euclidean plane. The subgraph is a tree, whose nodes represent the chosen terminals from the problem instance, and whose edges are line segments that connect two corresponding terminals. The tree is required to have the maximum number of nodes while the length is limited and is not sufficient to interconnect all the given terminals. The problem is shown to be NP-hard, and therefore a genetic algorithm is designed as an efficient practical approach. The method is suitable to various probable applications in layout optimization in areas such as communication network construction, industrial construction, and a variety of machine and electronics design problems. The proposed heuristic can be used as a general-purpose practical solver to reduce industrial costs by determining feasible interconnections among many types of components over different types of physical planes.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.50 no.12
• /
• pp.627-632
• /
• 2001

There are claims that ESE(Early streamer emission) Air terminals offer a vastly increased zone of protection over that of traditional lightning rods by causing the emission of an upward streamer/leader that will propagate towards the tip of downward leader at an early stage in the attachment process than would occur for a simple rod in the same geometrical configurations. This paper shows the results of comparing test a particular type of ESE air terminals with a simple rod conducted in the KEH HV laboratory, which are lightning impulse voltage test, flashover direction test and corona emission current measurement. The results from this test show a completely random scattering of flashovers to the conventional and ESE air terminals under identical electrics] and geometrical conditions, and thus shows no advantage of one terminal over the other.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.5
• /
• pp.755-761
• /
• 2002

Before the Internet was available, most application programs were executed using terminals, connected to host computers, as standard input output devices. The Internet is popular today and many services are provided on web browsers connected to the Internet. Since the standard I/O method used for terminals is different from the communication I/O methods used for web browsers, it is not possible to execute many application programs developed for the conventional terminals on web browsers. In this paper, we describe Web Input Output(WEBIO) library that enables application programs conventional on terminals to be executed on web browsers by recompilation without source modification. The WEBIO libraries for C and Prolog languages have been developed and they are under test now.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.5
• /
• pp.129-133
• /
• 2019

Frequency resource efficiency is important in satellite communication systems. One of the causes of a waste of frequency resource is bad flatness. In the case, flatness of satellite Tx terminals would be worse by ACI and guard band. In order to overcome this problem, this paper proposes a technique for frequency response equalization in satellite Tx terminals. First of all, a general linear polynomial expression which meets least squares of representative measurement data is calculated to interpolate unmeasured data. And then flatness can be adjusted using the polynomial expression. Simulation results illustrate adjusted data have lower peak to peak and standard deviation than original data, and these show that flatness be improved.

• Journal of information and communication convergence engineering
• /
• v.20 no.2
• /
• pp.90-95
• /
• 2022

This paper proposes a method to find a tree with the maximum number of terminals that can be connected by a given length when numerous terminals distributed in a cluster form are given to the Euclidean plane R2 with several constraints. First constraint is that a given terminal is distributed in a cluster form, second is that a given length cannot connect all terminals in the tree, and third is that there is no curved connection between each terminal. This paper proposes a method to establish more efficient interconnections within terminals distributed in a cluster form by improving a randomly distributed memetic genetic algorithm. The construction of interconnections has been extensively used in design-related fields, from networking to architecture. Additionally, in real life, the construction of interconnections is mostly distributed in the form of clusters. Therefore, the heuristic algorithm proposed in this paper can be effectively utilized in real life and is expected to provide various cost savings.

• Journal of Navigation and Port Research
• /
• v.29 no.10 s.106
• /
• pp.921-926
• /
• 2005

The purpose of this paper is to conduct a comparative analysis of container terminal operation in Busan and Kwangyang port. The research method used for this study is DEA(Data Envelopment Analysis} and among DEA methods CCR and BCC model has been used. According to the results of CCR model Gamman in 2004 and Gamcheon in 2004 are found to be the most efficient terminals in the sample and the inefficient terminals include Gwangyang Phase 2 terminal. Based on BCC model Gamcheon and Uam are identified as the most efficient terminals in three consecutive years including Gamman terminal in 2004. The inefficient terminals include New Gamman in 2002 and Hutchison in 2002. The research findings show that inefficient terminals need to fully utilise their terminal facilities and increase container throughput through effective marketing activities.

• Journal of Multimedia Information System
• /
• v.5 no.3
• /
• pp.163-170
• /
• 2018

We developed a multicast communication packet radio protocol using a time-sharing tablet system ("wireless token ring") to achieve the efficient exchange of files among packet radio terminals attached to swans. This paper provides an overview of the system and the protocol of the packet communications. The packet device forming the main part of the transceiver developed is the Texas Instruments CC2500. This device consists of one call-up channel and one data transmission channel and could improve error frame correction using FEC (forward error correction) with 34.8 kbps MSK and receiving power of at least -64 dBm (output 1 dBm at distance of 200 m using 3 dBi antenna). A time-sharing framework was determined for the wireless token ring using call sign ordinals to prevent transmission right loss. Tests using eight stations showed that resend requests with the ARQ (automatic repeat request) system are more frequent for a receiving power supply of -62 dBm or less. A wireless token ring system with fixed transmission times is more effective. This communication protocol is useful in cases in which frequency resources are limited; the energy consumed is not dependent on the transmission environment (preset transmission times); multiple terminals are concentrated in a small area; and information (position data and vital data) is shared among terminals under circumstances in which direct communication between a terminal and the center is not possible. The method allows epidemiological predictions of avian influenza infection routes based on vital data and relationships among individual birds based on the network topology recorded by individual terminals. This communication protocol is also expected to have applications in the formation of multiple in vivo micromachines or terminals that are inserted into living organisms.

• Journal of Navigation and Port Research
• /
• v.33 no.10
• /
• pp.735-742
• /
• 2009

Information security is an essential factor that enables terminal to be operated. However, despite of this importance of information security, there has hardly been any research related to this topic. And moreover, current level of information security performance in container terminals has not been analyzed so far. The objective of this study is to evaluate current level of information security in container terminals. Through survey from the four leading container terminal operators in Korea, The results firstly showed that average of information security level of major container terminals was 71.7%. And from the results of data analysis, it revealed that the weak point of information security in Korean container terminals was security management, and in detail, lack of expertise of support group.

• Journal of Navigation and Port Research
• /
• v.33 no.8
• /
• pp.555-562
• /
• 2009

At container terminals, a major measurement of productivity can be work-efficiency in quay-side. At the apron, containers are loaded onto the ship and unloaded to apron by Q/C(Quay Crane). For improving the productivity of quay crane, the more efficient Y/T(Yard Tractor) operation method is necessary in container terminals. Between quay-side and yard area, current transferring methods is single-cycling which doesn't start loading unless it finishes unloading. Dual-cycling is a technique that can be used to improve the productivity of quay-side and utility of yard tractor by ship loading and unloading simultaneously. Using the dual-cycling at terminals only necessitates an operational change without purchasing extra equipment. Exactly, Y/T operation method has to be changed the dedicate system to pooling system. This paper presents an efficient ship loading and unloading plan in container terminals, which use the dual-cycling. We propose genetic and tabu search algorithm for this problem.

• Applied Microscopy
• /
• v.18 no.1
• /
• pp.35-48
• /
• 1988

To investigate the connections between the major limbic structures and the nucleus accumbens septi or the nucleus fundus striati, stereotaxic surgeries were performed. One group of the rats were electrically lesioned in the mamillary body, and the other group were extirpated their hippocampal formation. Careful study of both nuclei following each surgery showed the following results. 1. Nerve terminals of mamillo-accumbens tract were synapsed to the dendrite of nucleus accumbens cell, whereas the neuronal type of accumbens-mamillary tract was aspiny cell. 2. Nerve terminals of mamillo-fundus tract were synapsed to the spines of fundus striati cells. Fundus-mamillary tract cells were not confirmed. 3. Nerve terminals of hippocampo-accumbens terminals were synapsed to the dendrites and spines of nucleus accumbens cells, whereas the neuronal type of accumbens-hippocampal tract was spiny one. 4. Nerve terminals of hippocampo-fundus tract were synapsed to the spines of fundus striati cells, whereas the neuronal types of fundus-hippocampal tract was aspiny one. 5. From the results, it was concluded that both of the nucleus accumbens septi and the fundus striati have connections with the mamillary body and the hippocampus. But nucleus accumbens septi has apparently more intimate relationship with major limbic structures.