• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.112-121
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• 1984

This paper is compared the simulation tables by the general propagation velocity and the calculated propagation velocities with distances and times to take to be transmitted Loran C wave from master station to slave stations, with Loran C tables, and compared the accuracy of position fixes by the simulation to them by Loran C table with the time differences of 9970 chain to be measured in the south coast of Korea, and by the simulation with the time differences of 5970 chain to be measured at definite position to them. The results obtained are as follows; 1. the simulation tables by the calculated propagation velocities is nearer to Loran C tables than it by the general propagation velocity. 2. The ranges of total errors of the simulation positions by the general propagation velocity and the calculated propagation velocities to the position fixies of Loran C table with the time differences of 9970 chain to be measured in the south coast of Korea are 0.2-0.7 miles, 0.01-0.1 miles, and the mean values of them are 0.46 miles and standard deviations of time are 0.1 miles, 0.03 miles respectively. 3. Mean value of total errors of the simulation position by the calculated propagation velocities to the definite position with the time difference of 5970 chain is 0.2miles and is reduced 0.1-0.2 miles than it by the general propagation velocity.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.3
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• pp.5-27
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• 2020

This study aimed at analyzing the keywords and authors of the KCI listed theological journals and finding the official research performance of Korean theology. This study divided the periods in two according to how duplicate the authors are and found hierarchical clusters by analyzing 92 keywords using the McQuitty method. In analyzing them, the Ward linkage method was selected to prevent the authors from gathering into a small number of clusters. Also, to find how influential the journals were to the keywords, the keywords and the percentage of the journals in them were presented together. The authors were analyzed in terms of deciding the positions of them using normalized performance index representing the number of journals and growth index as a growth tendency. Especially, significant researchers were all reformed theologians in a growth index. In the analysis of the keywords of the KCI journals and the authors, the main subject terms of the Korean theology were related to systematic theology and the New Testament. By analyzing the KCI listed journals as the Korean official citation index, this study has made a difference to the advanced articles analyzing the non-KCI listed theological journals.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.199-204
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• 2000

In this study, the ZnS nanosized thin films that could be used for fabrication of blue light-emitting diodes, electro-optic modulators, and n-window layers of solar cells were grown by the solution growth technique (SGT), and their structural and optical properties were examined. Based on these results, the quantum size effects of ZnS were systematically investigated. Governing factors related to the growth condition were the concentration of precursor solution, growth temperature, concentration of aq. ammonia, and growth duration. X-ray diffraction patterns showed that the ZnS thin film obtained in this study had the cubic structure ($\beta$-ZnS). When the growth temperature was $75^{\circ}C$, the surface morphology and the grain size uniformity were the best. The energy band gaps of samples were determined from the optical transmittance valued, and were shown to vary from 3.69 eV to 3.91 eV. These values were substantially higher than 3.65 eV of bulk ZnS, demonstrating that the quantum size effect of SGT grown ZnS is remarkable. Photoluminescence (PL) peaks were observed at the positions corresponding to the lower energy than that to energy band gap, illustrating that the surface states were induced by the ultra-fineness of grains in ZnS films. Particularly, for the first time, it is reported for the SGT grown ZnS that the PL peaks were shifted depending on the grain size.

• Journal of Korean Dental Science
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• v.10 no.1
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• pp.29-34
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• 2017

Purpose: The purpose of this study was to evaluate the microleakage of various types of resin-bonded fixed partial dentures (RBFPDs) after artificial aging. Materials and Methods: Forty models with missing first molar were fabricated using artificial resin teeth and were divided into four groups: Group A, conventional RBFPDs design; Group B, modified RBFPDs design; Group C, assembled 3-piece RBFPDs design; and Group D, assembled 3-piece RBFPDs with different occlusal rest positions. Half of the specimens underwent chewing simulation process (240,000 cycles, 50 N load, 1.7 Hz) and thermocycling (temperatures $5^{\circ}C{\sim}55^{\circ}C$, dwelling time 30 seconds) and the remaining 20 specimens didn't receive any treatment. All the specimens were immersed in 2% methylene blue solution for 24 hours to evaluate microleakage, and were sectioned at the middle part of abutment teeth. To evaluate the microleaskage, a dye penetration was calculated. Result: With artificial aging, cyclic loading and thermocycling, a 3-piece RBPFD and a 2-piece RBPFD using original tooth undercuts have significantly lower microleakge (P<0.05) compared to the conventional design of RBPFD and modified RBPFD. Conclusion: Within the limit of this experiment, the assembled RBFPDs exhibited a smaller microleakage than the conventional RBFPDs, implying that the assembled RBFPDs can be more effective for reducing the dislodgement of the RBFPDs.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.209-215
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• 2018

The purpose of this study is to grasp the overall policy decision system of sex crime prevention policy and analyze the interaction and pattern of actors in policy formation process. This is a useful way to identify the causes and ways to improve the policy if the sex crime prevention policy fails. As a research method, we used a model of advocacy through case analysis and language network analysis. In the external environment, low reporting of sex offenses, technical improvement and supplement for preventive management, consciousness of victims of sexual crimes, amendment of legislation, and support of the president. The conflicts between the advocacy coalition opposed the strong regulation, the prevention of recidivism, the expansion of the range of objects to be worn, the temporary effect of the system and the retrospective of the bill. As a problem-solving strategy, it was confirmed that the opposing positions of pros and cons of lack of manpower and negligence of management through the extension of the system were acutely opposed. In the context of media reports, this tendency is more likely to be understood as the concern of prevention and management at the central government level to prevent sex crimes. Therefore, although the methods of prevention of sex crimes have been insufficient in the past, it is hoped that this study will be helpful in breaking the link of negative policy vicious cycle.

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.35-47
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• 2007

The aim of this study was to make dental technicians recognize the importance of their professional self-concept, and to provide basic data to devise the educational programs and policies of establishing their positive professional self-concept. In addition, the investigator tried to present some improvement measures for dental technicians' actual services by examining their job satisfaction. Study findings are as follows: First, the score of study subjects' self-concept is 3.41($\pm$.58) (perfect score=5), middle or high in rank. As for the mean score of professional self-concept by realms, the self-concept of communication is 3.59($\pm$.67), the highest; the self-concept of leadership in the realm of professional service is 3.54($\pm$.75); the self-concept of skills is 3.50($\pm$.75); the self-concept of adaptability is 3.47($\pm$.69); and the recognizant level of satisfactory self-concept is 2.95($\pm$.81), below the normal. Second, as for the difference of professional self-concept according to general characteristics, such variables as age, marital states, and the length of one's service have a significant influence upon the recognition of self-concept. First, the self-concept of those whose age is between 31 and 35 is the highest (3.64$\pm$.49), and it is followed by that of those whose age is 36 and above (3.57$\pm$.77) and then that of those whose age is between 26 and 30 (3.31$\pm$.56)). And that of those whose age is below 25 is the lowest. The obove results show us that the professional self-concept of older study subjects is higher than that of younger ones in general(p<.01). As for marital states, that of married persons(3.54$\pm$.64) is higher than that of unmarried ones(3.35$\pm$.55)(p<.05). As for the length of one's service, that of longtime employees is higher than that of short-period workers(p<.01). In relation to positions, a manager's professional self-concept is the highest(3.89$\pm$.55) and that of an assistant technician is the lowest(3.17$\pm$.58). Study findings show that the professional self-concept of higher ranking technicians is higher than that of lower ones in general (p<.001). Based on the study findings, the investigator suggests followings: First, studies on the professional self-concept that is appropriate to the characteristics of dental technicians must be carried out with a new point of view. Second, a tool must be researched and developed in order for the professional self-concept of dental technicians to be measured. Third, if a new professional self-concept is established and a measuring tool is developed, a study on the relationship between dental technicians' professional self-concept and practice performance can be carried out again.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.2 s.302
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• pp.49-58
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• 2005

In this paper, we proposed a blind watermarking algerian to use characteristics of a scalar quantizer which is the recommended in the JPEG2000 and JPEG. The proposed algorithm shifts a quantization index according to the value of each watermark bit to prevent losing the watermark information during the compression by quantization. Therefore, the watermark is embedded during the process of quantization, not an additional process for watermarking, and is adaptively applied as a assigned quantizer according application areas. Before embedding process, a LFSR(Linear feedback shift register) rearranged the watermark for the security of the watermark itself and in the embedding process, a LFSR is used to hide the watermarking positions. Therefore the embedded watermark can he extracted by only the owner who knows the initial value of LFSR without the original image. The visual recognizable pattern such as a binary image was used as the watermark. The experimental results showed that the proposed algerian satisfies the robustness and imperceptibility corresponding to the major requirement of watermarking. The results showed the largest error rate to be $5.7\%$ for attack. The experimental result which compares the proposed algorithm with the Mohamed algorithm showed that the proposed algorithm was better than it, exactly $4\~5$ times for the attacks of JPEG and JPEG2000.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.2
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• pp.161-172
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• 1997

In this paper, electromagnetic scattering by a perfectly conducting strip grating on dielectric multilayers is analyzed for the normalized reflected and transmitted power by applying the Fourier-Galeakin moment method. The induced current density is expanded in a series of multiplication of chebyshev polynomials of the first kind and functions with appropriate edge boundary condition, the continuous condition of electromagnetic field is applied in the boundary planes. The confirm the validity of the proposed method, the nor- malized reflected and transmitted power obtained by varying the relative permittivity and thickness of each dielectric layers are evaluated and compared with those of the existing numerical method and a paper, and then the numerical results in this paper are in good agreement with those of the existing numerical method and the paper. The sharp variation position in the geometrically normalized reflected and transmitted power can be moved by the incident angle, grating period, and the relative permittivity and thickness of the dielectric multilayers, these sharp variation points which are called the Wood's anomaly of the Geome- trically normalized reflected power are observed as a main factor when the reflected powers of the higher order mode are transitted between propagating and evanescent modes, and the local minimum positions are slightly moved to the left hand direction in which grating period is getting small according to the increase of the relative permittivity of dielectric layers.

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.372-381
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• 2016

Purpose: The aim of this study was to determine the relationship between buccal bone thickness and gingival thickness by means of a noninvasive and relatively accurate digital registration method. Methods: In 20 periodontally healthy subjects, cone-beam computed tomographic images and intraoral scanned files were obtained. Measurements of buccal bone thickness and gingival thickness at the central incisors, lateral incisors, and canines were performed at points 0-5 mm from the alveolar crest on the superimposed images. The Friedman test was used to compare buccal bone and gingival thickness for each depth between the 3 tooth types. Spearman's correlation coefficient was calculated to assess the correlation between buccal bone thickness and gingival thickness. Results: Of the central incisors, 77% of all sites had a buccal thickness of 0.5-1.0 mm, and 23% had a thickness of 1.0-1.5 mm. Of the lateral incisors, 71% of sites demonstrated a buccal bone thickness <1.0 mm, as did 63% of the canine sites. For gingival thickness, the proportion of sites <1.0 mm was 88%, 82%, and 91% for the central incisors, lateral incisors, and canines, respectively. Significant differences were observed in gingival thickness at the alveolar crest level (G0) between the central incisors and canines (P=0.032) and between the central incisors and lateral incisors (P=0.013). At 1 mm inferior to the alveolar crest, a difference was found between the central incisors and canines (P=0.025). The lateral incisors and canines showed a significant difference for buccal bone thickness 5 mm under the alveolar crest (P=0.025). Conclusions: The gingiva and buccal bone of the anterior maxillary teeth were found to be relatively thin (<1 mm) overall. A tendency was found for gingival thickness to increase and bone thickness to decrease toward the root apex. Differences were found between teeth at some positions, although the correlation between buccal bone thickness and soft tissue thickness was generally not significant.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.3
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• pp.218-226
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• 2018

In partial edentulous patients, implant-assisted removable partial denture which provide additional retention and support by placing a small number of implants in strategic positions might be suitable treatment. This case of patient with loss of maxillary posterior teeth and moderate to severe wear of residual dentition, three implants were placed in the maxillary anterior edentulous area and then surveyed bridges were made including remaining anterior natural teeth. Posterior edentulous area was restored with distal extension removable partial denture (RPD). In addition, the worn mandibular natural teeth were restored with fixed prostheses. As a result, reduced vertical dimension and collapsed occlusal plane were rehabilitated, and improved functionally and aesthetically. The purpose of this case was to report the results of three-year follow-up of full mouth rehabilitation with anterior implant surveyed bridges and distal extension RPD.