• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.123-130
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• 2016

With the development of fast construction mode in shipbuilding market, the demand on accuracy management of hull is becoming higher and higher in shipbuilding industry. In order to enhance production efficiency and reduce manufacturing cycle time in shipbuilding industry, it is important for shipyards to have the accuracy of ship components evaluated efficiently during the whole manufacturing cycle time. In accurate shipbuilding process, block accuracy is the key part, which has significant meaning in shortening the period of shipbuilding process, decreasing cost and improving the quality of ship. The key of block accuracy control is to create a integrate block accuracy controlling system, which makes great sense in implementing comprehensive accuracy controlling, increasing block accuracy, standardization of proceeding of accuracy controlling, realizing "zero-defect transferring" and advancing non-allowance shipbuilding. Generally, managers of accuracy control measure the vital points at section surface of block by using the heavy total station, which is inconvenient and time-consuming for measurement of vital points. In this paper, a new measurement method based on point clouds technique has been proposed. This method is to measure the 3D coordinates values of vital points at section surface of block by using 3D scanner, and then compare the measured point with design point based on ICP algorithm which has an allowable error check process that makes sure that whether or not the error between design point and measured point is within the margin of error.

• Journal of Preventive Medicine and Public Health
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• v.28 no.3 s.51
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• pp.623-639
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• 1995

We have never seen any method to cope basically with complicated situation and problems around medical reimbursement rates here in Korea since 1977 witnessed by the beginning of medical insurance. By the way researchers concerned are beginning to propose some kinds of innovative and detailed ideas to government these days. They are Diagnosis-related group(DRG) and Resource-based .elative value scale(RBRVS). In the light of this situation it is so encouraging that our government can come up with that and move. In case of RBRVS research we have already been reaching even to the level of reviewing and revising methodology for its further development after naive pilot study on internal medicine and general surgery last year. However there might be something different conditions between USA and Korea to apply the same Dr. Hsiao's method and it must be vital to check so called' total work approach' compared with 'intra-service work approach' before expanding to the whole medical fields. According to the' Intra-service approach', the physician's work is supposed to be divided into three sub-works by the name of intraservice work, pre, and post service work. These sub-works, again should be merged together to be the pre-postwork subset through some statistical methods of the estimation process applied by Dr. Hsiao's methodology in RBRVS development later on. But in this paper that estimation process was not taken because we could have real values for all of those surveyed items related to just one specialty, OB & GY. Instead, We used some statistical comparison procedures relevant to demographic characteristics, reliability & validity and correlation analysis with American RVU(Relative value unit) between the total work and merged total work from intraservice work approach. The unit of analysis was individual physicians of OB & GY and 300 physicians were selected for each approach through statistical sampling method based on national population of OB & GY physicians in Korea. And also with the thankful help of Advisory Committee under Korean Association of OB & GY, questionnaires were made and mailed to the subjects, two times. As a result there were not any statistically significant differences in demographic characteristics between the two approaches except for the variable 'Response time for the questionnaires', but in other sections of comparisons, response rate, representative values, reliability & validity test, correlation analysis with American RVU, all showed 'Total approach' was not only more rational and statistically meaningful than 'Intra-service approach' but also had considerable merits. But we are not absolutely sure about this paper's robustness. Because of some limitations, we'd rather like to suggest further researches should be followed. In that sense the first thing would be a research for the influence of doctor's characteristics, especially 'frequency' on the rating of work and the way to define total work more clearly.

• Journal of radiological science and technology
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• v.32 no.1
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• pp.1-15
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• 2009

Newly published IEC 60601-1-3 ; 2008 2nd Edition has two important meanings. First, Radiation Quality and Dose should make sure for safety of patient and staff in manufacturing diagnostic X-ray equipment. Second, it should be minimized of Leakage Radiation, Residual Radiation, and Stray Radiation. The requirement to make enactment or revision of national standard for diagnostic X-ray Equipment is as follows : 1. It should be adjusted the new standard to the recent IEC Publication under the consideration of the Korea medical circumstances. 2. For focus to the Radiation Safety, IEC 60601-1-3 (General requirements for radiation protection in diagnostic X-ray equipment) could be applied to the new regulation. It should be compact sentence. 3. A sudden Notification change should not be desired. It needs a enough time to make easy the circumstances.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.359-370
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• 2000

The purpose of this investigation was to observe the viscoelastic properties of five commercial flowable(Aeliteflo, Flow it, Revolution, Tetric flow, Compoglass flow), three conventional hybrid(Z-100, Z-250, P-60) and two condensable(Synergy compact, SureFil) resin composites. A dynamic oscillatory shear test was done to evaluate the storage shear modulus (G'), loss shear modulus(G"), loss tangent(tan ${\delta}$) and complex viscosity(${\eta}^*$) of the resin composites as a function of frequency - dynamic frequency sweep test from 0.01 to 100 rad/s at $25^{\circ}C$ - by using Advanced Rheometric Expansion System(ARES). To investigate the effect on the viscosity of resin composites of filler volume fraction, the filler weight % and volume % were measured by means of Archimedes' principle using a pyknometer. The results were as follows 1. The complex viscosity ${\eta}^*$ of flowable resins was lower than that of hybrid resins and significant differences were observed between brands. The complex viscosity ${\eta}^*$ of condensable resins was higher than that of hybrid resins. The order of complex viscosity ${\eta}^*$ at ${\omega}$=10 rad/s was as follows, Surefil, Synergy compact, P-60, Z-250, Z-100, Aeliteflo, Tetric flow, Compoglass flow, Flow it, Revolution. The relative complex viscosity of flowable resins compared to Z-100 was 0.04~0.56 but Surefil was 30.4 times higher than that of Z-100. 2. The storage shear modulus G' and the loss shear modulus G" of flowable resins were lower than those of hybrid resins but those of condensable resins were higher. The patterns of the change of loss tangent, tan ${\delta}$, of resin composites with increasing frequency were significantly different between brands. The phase angles, ${\delta}$, ranged from $30.2{\sim}78.1^{\circ}$ at ${\omega}$=10 rad/s. 3. All composite resins represent pseudoplastic nature with increasing shear rate. 4. The complex shear modulus $G^*$ and the phase angle ${\delta}$ was represented by the frequency domain phasor form, $G^*({\omega})=G^*e^{i{\delta}}=G^*{\angle}{\delta}$. The locus of frequency domain phasor plots in a complex plane was a valuable method that represent the viscoelastic properties of composite resins. 5. There was no direct linear correlationship but a weak positive relation was observed between filler volume % or weight % and the viscosity of the resin composites.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.110-117
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• 2018

The aim of this study was to develop an analytical method for the quantification of diazepam residues in fishery products, using liquid and gas chromatography-tandem mass spectrometry (LC-MS/MS and GC-MS/MS). The sample utilized in the study was extracted from the fish sample (crucian carp) using 0.1% formic acid in acetonitrile. For the utilization of the purification process, the dispersive solid phase extraction (dSPE) was used for LC-MS/MS, dSPE and SPE was used for GC-MS/MS, respectively. To be sure, the standard calibration curves showed a good linearity as the noted correlation coefficients, $r^2$ was > 0.99. The average recoveries for accuracy ranged in 99.8~124% for the samples which were fortified at three different levels (0.001, 0.002 and 0.010 mg/kg). The correlation coefficient for the precision effect was measured at a range of 4.01~11.8%. The limit of detection (LOD) for the diazepam analysis was 0.0004 mg/kg, and the limit of the quantification (LOQ) was 0.001 mg/kg. The proposed analytical method was characterized with a high accuracy and acceptable sensitivity to meet the established Codex Alimentarius Commission (CAC/GL71-2009) guideline requirements. We therefore established the optimal analysis method for the determination of diazepam in the fishery products using LC-MS/MS and GC-MS/MS. It would be applicable to analyze the diazepam residues in fishery products in further studies on this subject.

• Restorative Dentistry and Endodontics
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• v.29 no.6
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• pp.548-552
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• 2004

Intracanal disinfection of infected root canal is one of important treatment procedure. This in vitro study aimed to evaluate whether the surface polymers of controlled release drug (CRD) can effectively control the release rate of chlorhexidine for root canal disinfection. Four CRD prototypes were prepared: Group A (n=12); The core device (absorbent paper point) was loaded with 40% CHX solution as control. Group B (n=12); same as group A, but the device was coated with chitosan. Group C (n=12); same as group A and then coated three times with 5% PMMA. Group D (n=12); same as group A and then coated three times with 3% PLGA. All CRD prototypes were soaked in 3 mL distilled water for experimental periods and the concentrations of released CHX from each CRD prototype were determined using a UV spectrophotometer. Results showed that release rate of CHX were the greatest in the non-coated group (control group), followed by the chitosan-coated group, the PLGA-coated group, and the PMMA-coated group (P < 0.05). This data indicate that surface polymers can control the release rate of CHX from the CRD prototypes.

• Journal of the Korean Geotechnical Society
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• v.27 no.10
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• pp.69-80
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• 2011

In this study unsaturated seepage analysis of 8 large rockfill dam managed by Korea Water Resources Corporation, were carried out, and the seepage rate of rockfill dam was analyzed by changing reservoir water level, shape, saturated and unsaturated seepage properties of core zone to present an equation to estimate steady-state seepage rate of rockfill dam. This equation considers unsaturated seepage flow and is applicable to domestic large scale Rockfill dam with the height of more than 50m. Estimated values by the proposed equation are greater than those by the method of Sakamoto (1998), which does not consider unsaturated seepage flow. The difference of estimated values increases with the lower reservoir water level and decreases with the higher reservoir water level. We can be sure that the comparison between the measured seepage rate and the estimated seepage rate by the proposed equation for the existing rockill dam was well-matched. The proposed equation is close to the actual phenomenon compared with the existing equations (Sakamoto, 1998; Chapuis and Aubertin, 2001) because it is based on the results of unsaturated seepage analysis of dams, has upstream and downstream slopes in the range of 1Vertical: (0.2~0.3)Horizontal.

• Korean Journal of Community Nutrition
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• v.12 no.4
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• pp.489-500
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• 2007

The purpose of this study was to determine factors affecting intention to participate in school breakfast programs of middle and high school students in Seoul using the Theory of Planned Behavior. Out of 2,280 questionnaires distributed to the middle and high school students, 2,060 were returned (90.4% response rate) and 1,799 were analyzed (78.9% analysis rate). To determine factors affecting intention to participate in school breakfast programs, logistic regression analyses were conducted for middle and high school students, respectively. For logistic regression, data of 1,217 out of 1,799 students (637 middle and 580 high school students) were used after excluding 582 students which had an answer 'Not sure' to the question about intention to participate in school breakfast programs. In case of middle school students, male than female students (OR = 1.504), the students who skipped all breakfast (OR = 1.851), who ate breakfast $1{\sim}2$ times (OR = 3.474) or $3{\sim}4$ times (OR = 1.950) than those who ate breakfast everyday during weekdays of the previous week were more likely to participate in school breakfast programs. In case of high school students, male than female (OR = 1.967), the students who skipped all breakfast (OR = 4.187), the students who ate breakfast $1{\sim}2$ times (OR = 3.024) or $3{\sim}4$ times (OR = 2.095) than those who ate breakfast everyday during weekdays of the previous week were more likely to participate in school breakfast programs. In addition, both possibility of middle and high school students' participation in school breakfast programs increased as the satisfaction with school lunch service (OR = 1.704, 1.653) increased. Middle school students who perceived their household income level 'low or middle low' (OR = 1.999) than those who perceived their household income level 'middle' and the students who had more positive 'attitude' (OR = 1.311) toward eating breakfast were more likely to participate in school breakfast programs. However, high school students who had higher 'perceived difficulty in access to breakfast' (OR = 1.370) were more likely to participate in school breakfast programs. The results of this study could be useful data to plan and develop school breakfast programs in Korea.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.835-846
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• 2020

Recent severe climate changes and extreme weather events have caused the uncommon types of forest ecosystem disturbances such as hails and gypsy moths. This paper describes the analysis of the forest ecosystem disturbances using ISODATA (Iterative Self-organizing Data Analysis Technique Algorithm) with the RapidEye and Sentinel-2 images, regarding the cases of the hail damages in Hwasun in 2017 and the gypsy moth damages in the Chiak Mountain in 2020. In the case of hail damages, the comparison of the June image of this study and the July field survey of the previous study showed that the damage severity increased from June to July as the drought overlapped after the trees were injured by the hails. In the case of gypsy moths, significant leaf damages were found from the image of June, and the damages were mainly distributed at the low-altitude slope near Wonju City. We made sure that satellite remote sensing is a very effective method to detect various and unusual forest ecosystem disturbances caused by climate change. Also, it is expected that the Korean Medium Satellite for Agriculture and Forestry scheduled to launch in 2024 can be actively utilized to monitor such forest ecosystem disturbances.

• Journal of Environmental Policy
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• v.14 no.4
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• pp.3-21
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• 2015

This paper attempts to determine the most reasonable and agreeable option for new MRV framework in Post-2020 Climate Regime as well as to develop South Korea strategies to reflect our national circumstances and capacities appropriately. The options for MRV framework considered here are 1) Dual MRV and 2) Unified MRV. We reached the conclusion that the Unified MRV framework may be the most reasonable option in the 2015 agreement in line with the objectives of MRV. To this end, it is essential to develop effective stepwise strategies consisted of: 1) reaching a consensus internally on the Unified MRV framework, 2) developing detailed procedures and methodologies to make the major elements of the Unified MRV framework understandable and predictable, 3) delivering an overview and blueprint to make sure of the flexibility of the Unified MRV framework to reflect the Parties' capacities and national circumstances, 4) ensuring the financial and technical support schemes for developing countries to improve the capacity-buildings of MRV, and 5) developing a realistic road map to successfully implement the Unified MRV scheme within the required time frame. Korea, as a rational mediator between developed and developing countries, should play a leading role in reaching post-2020 agreement.