• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1074-1081
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• 2021

It has recently been noticed that the headway of unlicensed wireless technology is necessary as user's demands of wireless tech increase and the development of high-speed data service by using low-power short-range wireless network is needed. Hence, it is inevitable to study sharing and coexistence for broadband spectrum of diverse unlicensed application with wide bandwidth. In this paper, an interference examination between unlicensed WiFi (Wireless Fidelity) in the 6GHz and OB (Outside Broadcasting) system which is an incumbent service in the same frequency band was conducted and it suggests separation distance for the coexistence. Thus, MCL (Minimum Coupling Loss) and MC (Monte Carlo) methods were used to set up interference scenarios for the interference analysis and compute the separation distance between two systems according to the same frequency band and frequency separation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.10
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• pp.843-850
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• 2013

Cognitive radio systems have been considered as a strong solution of frequency scarcity due to the limit of frequency resources. This paper proposed an active interference management scheme that the secondary system can coexist with the primary system in the same frequency band without interference. Using the proposed protocol, the secondary user acquires interference channel information and transmit/receive filter information and designs precoding matrix using these information. Since interference from the secondary systems are collected to unused subchannels of the primary system, the primary system can suppress interference without additional process. The secondary systems suppress interference from the primary system using whitening matched filter so that the spectral efficiency can be improved. Numerical results provides that the proposed scheme improves performance of the secondary systems without interference to the primary system and do not degrade performance of the primary system even if the number of the secondary systems increases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.4
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• pp.371-380
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• 2013

D2D (Device-to-Device) communication on an underlying cellular infrastructure which exploits the same spectrum has several advantages such as increased resource utilization and improved cellular coverage. However, D2D communication system needs to cope with ICI (Inter-Cell Interference) and interference between cellular and D2D links. As a result, macro UEs (User Equipments), especially those located near cell edge, will suffer from serious link performance degradation. We propose a novel interference avoidance mechanism assisted by SRN (Shared Relay Node) in this paper. SRN not only performs data re-transmission as a usual Type II relay but also has several features newly defined to avoid interference between cellular and D2D links. In particular, we suggest resource allocation methods based on the SRN for effective interference avoidance, and evaluate their performance through computer simulations.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.59
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• pp.87-100
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• 2006

Recently, a lot of countries including the USA, Japan and European countries are working on applying IT technologies to spectrum management. Korea has put the G4C(Government for Citizen) project in pace that enables customers to access online public services including authorization of radio station. To improve the spectrum access and use, it is required to develop advanced support system for spectrum policy. This study analyzed and compared the e-licensing systems of foreign countries with those of Korea, and considers what process and methods of e-licensing are needed for Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11C
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• pp.1095-1101
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• 2007

For the cognitive radio (CR) systems sharing the spectrum with narrowband primary devices, this paper presents a fractional bandwidth (FBW) mode utilizing a variable portion of the system band to avoid the interference to or from the primary devices. For the method, the preamble and FBW mode detection algorithm are provided to obtain the FBW mode information during the synchronization. Simulation results in wireless regional area network (WRAN) environments reveal that the FBW mode can be detected reliably without any deterioration of the synchronization performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.12
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• pp.1423-1436
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• 1992

In the paper, a CAT interface supporting multitask is realized. To interface a computer with measuring instruments, a GPIB card is designed and implemented. Controlling and displaying software using OOP and GUI are programmed with C++. A spectrum analyzer and a power meter are chosen as object instrument to be controlled. Total 9 modules are configured to manage the various resources and each module in integrated system. Also in case that several instruments are used, the system is realized to be capable of multitasking to exchange the data mutually. The multitasking is implemented under the time-sharing DOS environment. Thread-based method is used for processing, and Round Robin method for scheduling. Provided proper software modules for other object instruments are integrated, the system can control more measuring instruments simultaneously by the computer. Users can save the time and errors even without expert knowledge.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.666-675
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• 2008

The IEEE 802.22 standard is being developed with the target of improving the efficiency of spectrum utilization and importing the new wireless communication service. The WRAN standard based on Cognitive Radio is being processed for sharing TV bands. In this paper, the efficient spectrum allocation scheme and the optimal power allocation scheme, Partial Constant Power Water Filling (PCPWF), are proposed to maximize the channel capacity and spectrum efficiency and minimize the interference between adjacent cells. And we maximize the system throughput and fairness by using proposed dynamic cell plan that efficiently allocates channel. The results of the simulations are presented to verify the utilization of our proposed scheme.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.307-316
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• 2006

In this paper the analytical method, namely advanced minimum coupling loss(A-MCL), was proposed in order to analyze the coexistence of OFDM-based systems beyond 3G(B3G) with point-to point(PP) fixed service(FS) microwave systems. Our proposed method is based on a power spectral density(PSD) analysis. So it can be easily applicable to analyze the coexistence of OFDM-based systems B3G using flexible spectrum usage(FSU) with other systems, where the conventional MCL method cannot allocate transmit power partially to some subcarriers which overlap the band of a victim system. By applying the conventional MCL method and the A-MCL method, interfering power levels at the receiver of a interfered system are respectively calculated. A-MCL can calculate interference power more accurately than MCL by the maximum value of 4.5 dB. Therefore it can be concluded that our prosed method, namely A-MCL, is applicable to a sharing analysis of OFDM-based systems B3G.

• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.85-94
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• 1973

The stability constants of the charge-transfer complexes formed between three derivatives of nitrobenzene, i.e., 1,3,5-trinitrobenzene, m-dinitrobenzene, nitrobenzene and eleven organic molecules such as $\alpha-picoline$, pyridine, dimethylsulfoxide, N, N'-dimethylacetamide, tetrahydrofurane, 1, 4-dioxane, diethyl ether, acetonitrile, propylene oxide, epichlorohydrine, and methyl acetate, have been determined by ultraviolet absorption spectroscopy in carbon tetrachloride solution at 25.0$^{\circ}C$. The parameters of the electrostatic effect ($E_D$) and covalent effect ($C_D$) for the eleven organic compounds have been calculated from the modified equation of the double-scale enthalpy,$logK = E_AC_A+E_DC_D$ and also the shift of C=O vibrational frequency in infrared spectra for N,N'-dimethylacetamide have been measured from the solutions of above organic compounds. The empirical equation, ${\Delta}{\nu}_{C=O} = 37.4-5.47E_D+12.1C_D$, related to the parameters and the frequency shift has been derived. It seems that the stabilities of the complexes principally depend on the covalent effect. Especially it is found that $\pi$ orbitals in molecules, in addition to the parameters, play the important role in forming the charge-transfer complexes.

• Sim-seong Yeon-gu
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• v.28 no.2
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• pp.107-138
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• 2013

The purpose of this article is to awaken our colleagues to the culture and mind issues that have been forgotten or neglected by contemporary psychiatry under the prevalence of materialistic orientation. Cultural psychiatry too, though it has been contributed a great deal to widen the mental vision of psychiatry, has revealed several limitations in its approach. In the course of one sided search for culture specific factors in relation to mental health, conventional cultural psychiatry has neglected an effort to explore the common root underlying the different cultures and the common foundation of human mind. Cross sectional comparisons of the cultures alone have inevitably prevented the global considerations to culutre and mind in historical aspects and the dynamic interactions between mind and culture more in depth. The author suggested that the total view of mind and total approach of analytical psychology of C.G. Jung might be capable to replenish those limitations. Author explained the ways of C.G. Jung's observations and experiences of non-western culture and his concepts of culture and mind. The author demonstrated Jung's view of culture with the example of Filial Piety, Hyo, the Confucian moral norm which can be regarded as components of the collective consciousness though connected with archetypal patterns of behavior of intimacy between parent and child. In regard to the coexistence of multi-religious cultures in Korea the author made a proposal of 'culture spectrum' model for understanding value orientations of person in religious cultures. He identified in case of the Korean 4 types of cultural spectrums: Person with predominantly the Buddhist culture; with the Confucian; with the Shamanist; and with the Christian culture. The author also made an attempt to depict the dynamic interactions of different religious cultures in historical perspectives of Korea. Concepts of mind from the Eastern thoughts were reviewed in comparison with Jung's view of mind. The Dao of Lao Zi, One Mind by Wonhyo, the Korean Zen master from the 7th century, the Diagram of the Heaven's Decree by Toegye, a renowned Neo-Confucianist of Korea from the 16th century and his theory of Li-Ki, were explored and came to conclusion that they represent certainly the symbol of the Self in term of C.G. Jung. The goal of healing is 'the becoming whole person'. Becoming whole person means bringing the person as an individual to live not only within the specific culture but also to live in the world beyond the culture which is deeply rooted in the primordial foundation of human mind.