• Reproductive and Developmental Biology
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• 제30권1호
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• pp.59-64
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• 2006

This study was conducted to establish a convenient freezing method of boar semen. Boar semen was cooled until $5^{\circ}C$ for 3 hrs using cell freezer and loaded into straws. Semen straws were frozen in different steps in strofoam box filled with $LN_2$. Highest sperm viability (54.0%) was obtained by 1-step freezing(holding at 10 cm height from the surface of $LN_2$ for 10 min). Sperm viability increased by holding at $-102^{\circ}C$ for 10min (74.0%, P<0.05). In thawing regime, sperm viability was significantly higher in $37^{\circ}C$ group than in $52^{\circ}C$ group. The sperm characteristics did not differ between 1-step and 3-step. After IVF using frozen-thawed boar semen, developmental rate of embryos to the morula+blastocyst stage was in 1-step freezing group than that of 3-step freezing group (27.5 vs 14.7%, P<0.05). The result shows that the 1-step freezing with holding at $-102^{\circ}C$ for 10min before plunging into $LN_2$ is a convenient and easy freezing method for boar semen.

• Imaging Science in Dentistry
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• 제40권3호
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• pp.103-107
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• 2010

Purpose : This study was performed to examine the effects of image filter on observer performance by counting the number of holes at each wedge step on a radiographic image. Materials and Methods : An aluminum step wedge with 11 steps ranged in thickness from 1.5 mm to 16.5 mm in 1.5 mm increments was fabricated for this study. Each step had 10 notched holes with 1.0 mm diameter on the bottom of the step wedge which were ranged in depths from 0.1 mm to 1.0 mm in 0.1 mm increments. Digital radiographic raw images of the aluminum step wedge were acquired by using CCD intraoral sensor. The images were processed using several types of noise reduction filters and kernel sizes. Three observers counted the number of holes which could be discriminated on each step. The data were analyzed by ANOVA. Results : The number of holes at each step was decreased as the thickness of step was increased. The number of holes at each step on the raw images was significantly higher than that on the processed images. The number of holes was different according to the types and kernel sizes of the image filters. Conclusions : The types and kernel sizes of image filters on observer performance were important, therefore, they should be standardized for commercial digital imaging systems.

• Journal of Korean Academy of Nursing Administration
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• 제20권1호
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• pp.117-127
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• 2014

Purpose: In order to provide a systematic and standardized treatment course for MVD patients, a critical pathway (CP) program was developed and the results of its long term application were analyzed. Methods: This was a methodological study. The CP was established and applied to 75 (step I) and 1,216 (step II). Another group of 56 with similar features was used as a control group. Results: The application of CP turned out to be useful in many regards: the rate of hearing loss was reduced from 1.8% to 0% (step I) and 0.5% (step II), and low cranial nerve palsy was reduced from 1.8% to 1.3% and 0.7%, respectively. The length of hospitalization decreased by 2.56 days (25.2%) for step I and 3.05 days (30.0%) for step II. Days of ICU stay were reduced by 7.9% and 1.8%. The total cost per patient was reduced by 14.8% (step I). The cost per day was increased by 13.7% and 52.4%. An increase in the patient satisfaction index was noted, as shown in the ICU information guide (p=.002). Conclusion: The development and application of CP was found to improve the quality of medical treatment and the efficacy of hospital management in MVD patients. Well organized and efficient system and multidisciplinary teamwork are the key component of the successful application of CP.

• Journal of the Korea Safety Management & Science
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• 제11권4호
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• pp.201-211
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• 2009

The types and quantities of Hazmat and Hazmat transportation are gradually increasing, keeping pace with industrialization and urbanization. At present the safety management for Hazmat transportation only considers reducing accident probability, but even when an accident involving Hazmat-carrying vehicles occurs, that is not regarded as a Hazmat-related accident if the Hazmats do not leak out from the containers carrying them. Thus the methods to reduce risk (Risk=Probability$\times$Consequence) have to be developed by incorporating accident probability and consequence. By using Geographic Information System (GIS), a technical method is invented and is automatically able to evaluate the consequence by different types of Hazmat. Thus this study analyzed the degree of risk on the links classified by the Hazmat transport pathways. In order to mitigate the degree of risk, a method of 7-step risk management on Hazmat transportation in railway industries can be suggested. (1st step: building up GIS DB, 2nd step: calculating accident probability on each link, 3rd step: calculating consequence by Hazmat types, 4th step: determination of risk, 5th step: analysis of alternative plans for mitigating the risk, 6th: measure of effectiveness against each alternative, and 7th step: action plans to be weak probability and consequence by the range recommended from ALARP). In conclusion, those 7 steps are used as a standardization method of optimum transportation routing. And to increase the efficiency of optimum transportation routing, optional route can be revise by verification.

• The Journal of Korean Academy of Prosthodontics
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• 제29권3호
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• pp.87-99
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• 1991

The effect of oven firing on the color stability and surface texture of extrinsic stains used characterization and color modification of metal cermic restoration were studied by comparing different temperatures and techniques. They were autoglaze technique, applied glaze technique, two step low-fusing glaze technique and one step low-fusing glaze technique. Autoglaze technique and applied glaze technique were air-fired to manufacturer's recommended temperature. Two step low-fusing glaze technique is separated staining and overglazing. Thin slurry of stain powder were air-fired to $1500^{\circ}F$, Overglaze powder powder was then mixed with seam medium and air-fired to $170^{\circ}F$. One step low-fusing glaze technique is combined staining and overglazing. Thin slurry of stain and glaze powder were air-fired to $170^{\circ}F$. The obtained results were as fellows. 1. Slightly significant color differences by colorimeter were found between different stain application and fusion techniques(P<0.05). 2. Two step low-fusing glaze method showed the most rough surface, especially ceramco orage stain(P<0.05). 3. Surface roughness increased gradually in order of autoglaze, applied glaze, one step low-fusing glaze but they were not significantly different(P<0.05). 4. When two step low-fusing glaze was applied, both color measurement and surface texture were sinificantly different from other groups(P<0.05).

• Journal of Navigation and Port Research
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• 제35권1호
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• pp.23-30
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• 2011

This study was carried out in order to verity the usefulness of FSA(Formal Safety Assessment) methods as a tool to conduct a safety assessment of general cargo ships flying the Korean flag, and to provide useful information on 'the Safety of General Cargo Ships' for IMO committee's discussion on the matter at a future session. In the previous paper, "A Study on High-level FSA for Korean-flagged General Cargo Ships(1)", the concepts of the FSA methodology and its five steps were described and the results of Hazard Identification(Step 1) and Risk Analysis(Step 2) from the FSA study for the Korean-flagged general cargo ships were discussed. Subsequent to the Steps 1 & 2, the identification of Risk Control Options(RCOs-Step 3) for eliminating or reducing either the frequency or the severity of the risks identified and their Cost-Benefit Assessment(CBA-Step 4) were undertaken. In this paper, the results of the Steps 3 & 4 are discussed, and some recommendations are made.

• Journal of the Institute of Electronics Engineers of Korea SP
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• 제43권1호
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• pp.75-84
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• 2006

With considering center-biased characteristic, NTSS(New Three-Step Search Algorithm) can improve the performance of TSS(Three-Step Search Algorithm) which is one of the most popular fast block matching algorithms(BMA) to search a motion vector in a video sequence. Although NTSS has generally better Quality than TSS for a small motion sequence, it is hard to say that NTSS can provide better quality than TSS for a large motion sequence. It even deteriorates the quality to increase a search window size using NTSS. In order to address this drawback, this paper aims to develop a new adaptive window size-based three step search scheme, called AWTSS, which can improve quality at various window sizes in both the small and the large motion video sequences. In this scheme, the search window size is dynamically changed to improve coding efficiency according to the characteristic of motion vectors. AWTSS can improve the video quality more than 0.5dB in case of large motion with keeping the same quality in case of small motion.

• Atmosphere
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• 제25권3호
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• pp.473-482
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• 2015

In this study, street canyons with a higher downwind building (so called, step-up street canyons) are considered for understanding characteristics of flow and reactive pollutants' dispersion as a basic step to understand the characteristics in wider urban areas. This study used a CFD_NIMR_SNU coupled to a chemistry module just including simple $NO_X-O_3$ photochemical reactions. First, flow characteristics are analyzed in step-up street canyons with four aspect ratios (0.33, 0.47, 0.6, 0.73) defined as ratios of upwind building heights to downwind building height. The CFD_NIMR_SNU reproduced very well the main features (that is, vortices in the street canyons) which appeared in the wind-tunnel experiment. Wind speed within the street canyons became weak as the aspect ratio increased, because volume of flow incoming over the upwind building decreased. For each step-up street canyon, chemistry transport model was integrated up to 3600 s with the time step of 0.5 s. The distribution patterns of $NO_X$ and $O_3$ were largely dependent on the mean flow patterns, however, $NO_X$ and $O_3$ concentrations were partly affected by photochemical reactions. $O_3$ concentration near the upwind lower region of the street canyons was much lower than background concentration, because there was much reduction in $O_3$ concentration due to NO titration there. Total amount of $NO_X$ in the street canyons increased with the aspect ratio, resulting from the decrease of mean wind intensity.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제43권9호
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• pp.814-821
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• 2015

The STEP Cube Lab. classified as a pico-class satellite has been successfully developed as a flight model(FM) to be launched in 2015. Its mission objective is to perform the on-orbit verification of fundamental space core-technologies. In this study, a thermal design concept based on the passive method to achieve the mission objective is introduced. The effectiveness of the thermal design and performance of the satellite has been verified through the acceptance level thermal vacuum test. In addition, to improve the reliability of thermal mathematical model, correlation was performed using the results of thermal balance test. This paper describes a series of process for the thermal vacuum test on the STEP Cube Lab. FM.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.747-748
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• 2009