• Journal of the Korean Professional Engineers Association
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• v.34 no.5
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• pp.69-72
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• 2001

The national 2G-3G roaming is emerging as one of essential and important issues In Korea in connection with the recent granting of 3G licenses. Accustomed to the current seamless coverage and superb quality of 2G networks, many subscribers have very high expectations of an equal or better service provisioning by 3G networks. However, it is very unlikely for 3G operators to successfully build their networks as comprehensive as the current 2G networks in the beginning of network implementation and commercial launch. Therefore,3G operators are seriously considering the national 2G-3G roaming in Korea. In this paper. 1 would like to discuss and present a technical implementation scheme and problems that need to be solved fer successfully realizing the national 2G-3G roaming.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.1-9
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• 1999

The purpose of this study is to establish a basis for assessing construct validity of measures used in organizational research. The classic Campbell and Fiske's(1959) criteria are found to be lacking in their assumptions, diagnostic information, and power. The inherent confounding of measurement error with systematic trait and method effects is a severe limitation for a proper interpretation of convergent and discriminant validity. The confirmatory factor analysis(CFA) approach overcomes most of the limitations found in Campbell and Fiske's(1959) method. However, the CFA approach confounds random error with unique variance specific to a measure. The second-order confirmatory factor analysis(SOCFA) was shown to harbor rather restrictive assumptions and is unlikely to be met in practice. The first-order, multiple-informant, multiple-item(FOMIMI) model is a viable option, but it may also be of limited use because of the large number measures.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.319-322
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• 2002

In this paper, we present a digital authentication technique using content-based watermarking in digital images. To digest the image contents, Hopfield network is employed on the block-based edge image. The Hopfield function extracts the same tit fur similarly looking blocks so that the values are unlikely to change to the innocuous manipulations while being changed far malicious manipulations. By inputting the extracted bit sequence with secret key to the cryptographic hash function, we generate a watermark for each block by seeding a pseudo random number generator with a hash output Therefore, the proposed authentication technique can distinguish between malicious attacks and innocuous attacks. Watermark embedding is based on the block-based spread spectrum method in DCT domain and the strength of watermark is adjusted according to the local statistics of DCT coefficients in a zig-zag scan line in AC subband. The numerical experiments show that the proposed technique is very efficient in the performance of robust authentication.

• Publications of The Korean Astronomical Society
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• v.14 no.2
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• pp.69-78
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• 1999

We present the results of one-dimensional numerical simulations of SNR evolution in the in­homogeneous medium considering the effects of the evaporation of the cloud and the thermal conduction. We have included the effects of changing evaporation rate as a function of cloud size and the ambient temperature so that the clouds could be evaporated completely before they reach the center of the SNR. The heat conduction markedly changes the density distribution in the remnant interior. To explain the observed morphologies of the centrally peaked X-ray SNRs(for example W44), the maximal thermal conduction is required. However, this is unlikely due to the magnetic field and the turbulent motion. The effects of the evaporation of the cloud and the thermal conduction described here may explain the class of remnants observed to have centrally peaked X-ray emmision.

• The Journal of Fisheries Business Administration
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• v.30 no.2
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• pp.79-89
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• 1999

This study is conducted to apply the insight of Johnson and Libecap(1982) to Korea's coastal vessel fishing. According to Johnson and Libecap(1982) the differences in fishing ability are largely attributed to acquired knowledge and innate skills. Since those skills are unlikely to be readily transferable assets, economic rents exist in the fishery, even under open access conditions. Therefore the paper tries to examine whether the acquired information from fishing experience and innate skill could also have an effect on catch variation of coastal vessel fishing in Kyung-Nam province. To do so, the paper is performing the analysis by establishing econometric model. Results show us that the acquired information from fishing experience have a significant effect on catch variation, but the innate skill does not.

• Korean Journal of Biological Psychiatry
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• v.3 no.1
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• pp.3-13
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• 1996

Many studies have been conducted to search for the anatomical abnormalities in the brain which ore etiologically related with schizophrenia. Generally schizophrenia in known to be related with decreased brain tissue, hypofrontality and abnormalities in the temporal lobe including the hippocamypus, the agmygdala and the entorhinal cortex. Other areas related with the disorder ore basal ganglia, thalamus, brain stem, pons and nucleus accumbens. Abnormality in brain asymmetry is one of the new areas of interest which needs further study. The results so for ore inconsistent and it is unlikely that the abnormality in one structure is the only cause of the disorder. Rather, schizophrenia develops from the impairment of the parallel processing of integrated and reciprocal information which is distributed to the multiple structures. Histopathologic studies in the postmortem brain suggest that schizophrenia is related with neurodevelopmental abnormality rather than neurodegenerative abnormality.

• The Korean Journal of Community Living Science
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• v.12 no.1
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• pp.29-40
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• 2001

This work was conducted to observe the housewives´ recognition about GMO products and their opinions about the development and production of GMO. Seventy eight percent of the subjects in this study were aware of GMO and GMO product which is best known to them was bean. Only 6.2% of the subjects considered GMO as safe and 42.1% did not know whether it is safe or not. Most of the subjects were unlikely to choose to purchase the GMO because of unproved safety, but many subjects were willing to purchase if the safety was informed with high reliability, even though 25.9% of the subjects were still negative. But when GMO product is offered with low price compared with ordinary products, only 24.6% were willing to purchase, showing that the safety was considered more important than the low price.

• Structural Monitoring and Maintenance
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• v.2 no.4
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• pp.301-318
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• 2015

This is the story of a bell-tower and its monitoring. The Civic Tower in Portogruaro is a 59 m high masonry bell-tower, originally built in the XIII century, today leaning more than a meter out of plumb. Since 2003, the building inclination has been continuously monitored with an optical inclinometer in an effort to see whether the tilt is still in progress. When the monitoring started, it was thought highly unlikely that the Tower would tilt further. After three years of monitoring and historical investigation, this idea was completely overturned. We show here how the initial view developed to a final awareness via a probabilistic analysis of the information acquired, based on Bayesian logic. We illustrate how the joint use of instrumental monitoring and historical documentation allowed timely recognition of signs of ongoing tilting and accurate calculation not only of the mean inclination trend, but also the credibility of this information.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2
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• pp.95-100
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• 1997

In this paper, we present a new fast VQ encoding algorithm. The proposed algorithm facilitates two characteristics of a vector, i.e., mean and variance to reject many unlikely codewords and save a lot of computation time. Since the proposed algorithm, which is based upon geometric considerations, rejects those codewords that are impossible to be the closest codeword, it provides the same results as a conventional exhaustive(or full) search algorithm. The simulation results confirm the effectiveness of the proposed algorithm.

• Bulletin of the Korean Chemical Society
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• v.25 no.11
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• pp.1657-1660
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• 2004

Several critical geometries associated with the rearrangement of $CH_3SNO_2\;to\;CH_3SONO$ are calculated with the density functional theory (DFT) method and compared with those of the ab initio molecular orbital methods. There are two probable pathways for this rearrangement, one involving the transition state of an oxygen migration and the other through the homolytic decomposition to radicals. The reaction barrier via the transition state is about 60 kcal/mol and the decomposition energy into radicals about 35 kcal/mol, suggesting that the reaction pathway via the homolytic cleavage to radical species is energetically favorable. Since even the homolytic cleavage requires large energies, the rearrangement reaction is unlikely without the aid of catalysts.