• The Journal of Korean Academy of Prosthodontics
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• v.38 no.2
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• pp.242-254
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• 2000

Accurate impression is very important to achieve desirable prosthesis and there are many factors in taking a good impression. For example, types of impression material, types of impression tray, impression taking methods and so on. Recently individual tooth tray technique is accepted as obtaining good impression that can be applied to multiple abutment impression, heavy salivated patient, to minimize the effect of natural teeth s undercuts and to reduce pain during cord packing procedures. The purpose of this study was to compare the accuracy according to materials and forms of the individual tooth tray which is clinically applied nowadays. Used materials in experiment were divided into 3 types (acrylic resin. $Futar^{(R)}$ occlusion. $Blu-mousse^{(R)}$) and forms were divided into 2 types (forming occlusal vent hole or not and forming marginal vent space or not). Stone master model from impression body and metal master model were measured by $X-PLAN360d^{(R)}$ to compare occlusal surface discrepancy and marginal discrepancy. The results were as follows: 1. In comparison of occlusal surface discrepancy and marginal discrepancy according to materials, groups with three materials showed no statistical difference 2. In comparison of occlusal surface discrepancy and marginal discrepancy according to occlusal vent hole, groups with occlusal vent hole showed significantly less marginal discrepancy than groups with no occlusal vent hole(p<0.05). 3. In comparison of occlusal surface discrepancy and marginal discrepancy according to 0.5mm-marginal-vent-space, groups with no 0.5mm-marginal-vent-space showed significantly less marginal discrepancy than groups with 0.5mm-marginal-vent-space (p<0.05). In summary these results suggest that individual tooth tray made of 3 types of materials with occlusal vent hole and individual tooth tray made of acrylic resin with no marginal vent space showed good accuracy of impression. In addition, individual tooth tray which is made of bite registration materials may be more useful because of advantage in facility and timesaving aspect of fabrication.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.191-197
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• 2019

As the shipbuilding and offshore plant industries grow larger and more complex, their maintenance and inspection systems become more important. Recently, maintenance and inspection systems based on augmented reality have been attracting much attention for improving worker's understanding of work and efficiency, but it is often difficult to work with because accurate matching between the augmented model and reality information is not. To solve this problem, marker based AR technology is used to attach a specific image to the model. However, the markers get damaged due to the characteristic of the shipbuilding and offshore plant industry, and the camera needs to be able to detect the entire marker clearly, and thus requires sufficient space to exist between the operator. In order to overcome the limitations of the existing AR system, in this study, a markerless AR was adopted to accurately recognize the actual model of the pipe system that occupies the most processes in the shipbuilding and offshore plant industries. The matching methodology. Through this system, it is expected that the twist phenomenon of the augmented model according to the attitude of the real worker and the limited environment can be improved.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.414-424
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• 1998

Purpose: Cross-modality coregistration of positron emission tomography (PET) and magnetic resonance imaging (MR) could enhance the clinical information. In this study we propose a refined technique to improve the robustness of registration, and to implement more realistic visualization of the coregistered images. Materials and Methods: Using the sinogram of PET emission scan, we extracted the robust head boundary and used boundary-enhanced PET to coregister PET with MR. The pixels having 10% of maximum pixel value were considered as the boundary of sinogram. Boundary pixel values were exchanged with maximum value of sinogram. One hundred eighty boundary points were extracted at intervals of about 2 degree using simple threshold method from each slice of MR images. Best affined transformation between the two point sets was performed using least square fitting which should minimize the sum of Euclidean distance between the point sets. We reduced calculation time using pre-defined distance map. Finally we developed an automatic coregistration program using this boundary detection and surface matching technique. We designed a new weighted normalization technique to display the coregistered PET and MR images simultaneously. Results: Using our newly developed method, robust extraction of head boundary was possible and spatial registration was successfully performed. Mean displacement error was less than 2.0 mm. In visualization of coregistered images using weighted normalization method, structures shown in MR image could be realistically represented. Conclusion: Our refined technique could practically enhance the performance of automated three dimensional coregistration.

• Imaging Science in Dentistry
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• v.39 no.3
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• pp.149-156
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• 2009

Purpose : The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. Materials and Methods : We devised a patient-specific stent for patient-to-image registration and navigation. Three-dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. Results : The accuracy over 8 anatomical landmarks showed an overall mean of $0.56{\pm}0.16\;mm$. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. Conclusion : The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.

• Journal of Animal Science and Technology
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• v.50 no.1
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• pp.33-44
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• 2008

The purpose of this study was to estimate the genetic parameters and trend of Landrace and Yorkshire pigs, which were raised on private farms from 1999 to 2005 and tested for their reproductive performance by the Korea Animal Improvement Association. Prior to analysis, records without pedigree or having value with larger than±3×standard deviation for the Total number of born were excluded. The effects of breed and environmental factors were estimated with least square method(Harvey, 1979), and estimation of breeding values and genetic parameters were performed on the data of 1’st litter only with GIBBSF90(Misztal, 2001) which was programmed according to Gibbs Sampling method based on Bayesian Inference by Gianola and Fernando(1986), Jensen(1994) and others. Gibbs sampling was performed 50,000 times for each parameter, and the first 5000 samples were regarded as those in burn-in period and thus, excluded for post hoc analysis. Total number of born and total number of accident were statistically significant(p<0.01) for the breed, farrowing year, farrowing season and parity effects, and the number born alive at birth was statistically significantp<(0.01) for the breed, farrowing year, farrowing season and parity effects. No particular trend was observed in the genetic and phenotypic improvement of the total number of born and number born alive at birth before 2001, when the piglet registration system started, but the tendencies of increasing for the total number of born and number born alive and decreasing for the total number of accident were observed since 2001. Somewhat higher heritability estimates of our study seems to be attributed to the situations that first parity records with poor farrowing performances were used in the analyses and it was impossible to obtain accurate reproductive performance due to the absence of criteria for record keeping at the level of individual farms.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.1
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• pp.119-152
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• 2009

Korea now has a rapidly expanding and developing space programme with exploration aspirations. The government is giving priority to the aerospace industry and, to put it on a better footing, enacted an Aerospace Industry Development Promotion Act in I987, a Space Development Promotion Act in 2005 and a Space Compensation for Damage Act in 2007. I would like to describe briefly the legislative history, main contents and comment for these three space acts including especially launch licensing, registration of space objects, use of satellite information, astronaut rescue, liability for compensation, third party liability insurance and establishment of committee and plans to assist the Korean space effort. Furthermore author proposed to legislate a new draft for the establishment of a Korean Aerospace Development Agency (KADA: tentative title) to create a similar body to Japan Aerospace Exploration Agency (JAXA), British National Space Centre (BNSC) of UK, French Centre National d'Etudes Spatiales (CNES), German Aerospace Center (DLR), Swedish Space Corporation (SSC), China Aerospace Science and Industry Corporation (CASIC), Indian Space Research Organization (ISRO) as well as the Korean Space Agency (KSA: Tentative title) to create a similar body to Canadian Space Agency, European Space Agency, Russian Space Agency, Italian Space Agency, Israel Space Agency, Indian Department of Space, National Aeronautics and Space Administration (NASA) of USA, China National Space Administration in order to develope efficiently space industry. If the Korean government will be establish the Korean Space Agency as an governmental organization in future, it is necessary to revise the contents of the Government Organization Act. It is desirable and necessary for us to establish an Asian Space Agency (ASA), in order to develop our space industry and to promote research cooperation among Asian countries, based on oriental idea and creative powers.

• Advances in pediatric surgery
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• v.7 no.2
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• pp.147-156
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• 2001

Membership qualifications and recognition of the subspecialty training programs by the Korean Association of Pediatric Surgeons(KAPS) have been determined by criteria based on the number of neonatal and total pediatric surgical cases registered, since 1989 (Index cases). The numbers are based on a survey of the 14 founding members of the society by Jung et al. in 1987. The current survey is to review the present status of the index cases from 1997 to 1999 among 36 members of the KAPS. Two surveys were undertaken for this study. In the first survey, cases were collected by the registration form, composed of neonatal(N), important pediatric surgical cases (I), tumor and other similar operations(T) and other common pediatric surgical cases(O). Thirty members responded. and the result was discussed at the Topic Discussion section of the 15th Annual Congress of KAPS, 2000. The second survey analyzed additive data, proposed during discussion at the Congress. Twenty-three members responded. This report is the analysis of the both surveys. The average numbers of the cases/year/surgeon of N, I, T, O and total were 19.5, 51.8, 9.5, 77.1 and 356.5. respectively. The number of index cases(N+I+T)/year/surgeon was 80.8. The ratio of (N+I+T)/total cases was 0.3. Seventeen of 30 members have more than 20 cases of N per year. Twelve members have more than 150 cases, and 13 do more than 100 cases of I per year. Fourteen members have more than 10 cases of T per year. Nineteen and 10 members experienced more than 150 and 100 of index cases(N+I+T) per year. A new list of the index cases and coding system are proposed for the future regular update.

• Journal of Korean Academy of Nursing Administration
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• v.4 no.2
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• pp.321-349
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• 1998

Since 1990 the effort for unification has been active in each department of our society. But the study for health policy in Unified Korea has been scarce. Unified Korea should be a democracy and a constitutional state. So we should have lively discussion on the health law as well as unified general laws. The purpose of this study is to compare the health law of South Korea and North Korea and to understand the differences in them. We guess both Korea are considerably different each other. But this study found out that there are many health related laws that have same goals and contents. The reason for this is that both health laws have its root in Korea Law. And the right to health is the social basic right. whose characteristic can not be compatible with market economy and demands state intervention for securing the right to health. The health related laws are divided into 4 fileds. 1. There is a field A which is affected by unified political and economic system and differs little from the law system: the license system of medical personnel. 2. There is a field B which is seldom affected by unified political and economic system and differs little from the law system: the right and duty of medical personnel. quarantine law. 3. There is a field C which is affected by unified political and economic system and differs greatly from the law system: health institution law(exclusive of quarantine law), the laws of medical personnel category, of research center(especially per-mission, registration and establishment). of the role of basic health in private and public area. 4. There is a field D which is seldom affected by unified political and economic system and differs greatly from the law system: health equipment law(the laws of drugs, of cosmetics and of medical instrument. of blood management). the laws of health knowledge. of cooperation in chinese medicine and western medicine. the health promotion law. the rules of first-aid. the law of separation of dispensary from medical practice. The laws which are seldom affected by political and economic system can be consolidated. which in turn can be revised and enacted before unification of Korea through the interchange between North Korea and South Korea and the support to North Korea health system.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.83-89
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• 2016

This study was designed to determine the mutagenic potential of hydrolyzed glycomacropeptide (GMP) powder (hereafter referred to as 23%-GNANA; product name: HELICOBACTROL-23) in a micronucleus test using bone marrow in ICR mice. Three experimental groups were used: a 3-step concentration group, with a maximum concentration of 2,000 mg/kg, and other sequentially two-fold lower concentrations, a negative control group, and a positive control group. The test material was administered for 2 d to observe the frequency of micronucleus formation up to 48 h after the test material was absorbed by the body. When the polychromatic erythrocyte (PCE) content of erythrocytes was compared, no significant differences were noted between the negative control group and the test group (p<0.05). Similarly, when the average numbers of micronucleated PCE (MNPCE) in 2,000 PCE per animal were compared, no significant difference was observed between the negative control group and the test group (p<0.05). No dose-response relationship with regard to the concentration of the test material administered was noted. These results allow us to conclude that hydrolyzed whey protein powder does not cause formation of micronuclei in mouse bone marrow cells under the applied conditions. In this study, the average frequency of micronucleus formation in PCE was significantly higher in the positive control group compared with the negative control group; thus, the test conditions were appropriate for detecting the frequency of micronucleus formation induced by the test material. In conclusion, the safety of 23%-GNANA test substance was verified in an in vivo micronucleus test in mice, conducted before the registration of HELICOBACTROL-23 as a food additive.

• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.559-571
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• 2003

ENUM(tElephon NUmbering Mapping) is protocol that brings convergence between PSTN Networks and IP Networks using a unique worldwide E.164 telephone number as an identifier between different communication infrastructure. The mechanism provides a bridge between two completely different environments with E.164 number; IP based application services used in PSTN networks, and PSTN based application services used in IP networks. We propose a new way to organize and handle ENUM Tier 2 name servers to improve performance at the name resolution process in ENUM based application service. We build an ENUM based network model when NAPTR(Naming Authority PoinTeR) resource record is registered and managed by area code at the initial registration step. ENUM promises convenience and flexibility to both PSTN and IP users, yet there is no evidence how much patience is required when users decide to use ENUM instead of non-ENUM based applications. We have estimated ENUM response time, and proved how to improve performance up to 3 times when resources are managed by the proposed mechanism. The proposition of this thesis favorably influences users and helps to establish the policy for Tier 2 name server management.