• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.236.1-236.1
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• 2003

Evaluation of solid surface properties is very important for formulation of solid dosage form, specially insoluble drugs. The contact angle of insoluble drugs was measured by the penetration rate into powder bed using Washburn equation and wicking method. From the measured contact angle data, the surface free energy value of pharmaceutical powders ${\gamma}$s was divided and analysized into the polar component, ${\gamma}$s$\^$p/ and the dispersion component, ${\gamma}$s$\^$d/. Furthermore, the data was interpreted for acid part, ${\gamma}$s$\^$+/ and base part, ${\gamma}$s$\^$$\square$/ of surface free energy. (omitted)

• 한국대기환경학회지
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• 제19권5호
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• pp.595-610
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• 2003

The statistical indexes such as RMSE (Root Mean Square Error), Mean Bias error, and IOA (Index of agreement) are used to evaluate 3 Dimensional wind and temperature fields predicted by operational meteorological model RAMS (Regional Atmospheric Meteorological System) implemented in CARIS (Chemical Accident Response Information System) for the dispersion forecast of hazardous chemicals in case of the chemical accidents in Korea. The operational atmospheric model, RAMS in CARIS are designed to use GDAPS, GTS, and AWS meteorological data obtained from KMA (Korean Meteorological Administration) for the generation of 3-dimensional initial meteorological fields. The predicted meteorological variables such as wind speed, wind direction, temperature, and precipitation amount, during 19 ∼ 23, August 2002, are extracted at the nearest grid point to the meteorological monitoring sites, and validated against the observations located over the Korean peninsula. The results show that Mean bias and Root Mean Square Error are 0.9 (m/s), 1.85 (m/s) for wind speed at 10 m above the ground, respectively, and 1.45 ($^{\circ}C$), 2.82 ($^{\circ}C$) for surface temperature. Of particular interest is the distribution of forecasting error predicted by RAMS with respect to the altitude; relatively smaller error is found in the near-surface atmosphere for wind and temperature fields, while it grows larger as the altitude increases. Overall, some of the overpredictions in comparisons with the observations are detected for wind and temperature fields, whereas relatively small errors are found in the near-surface atmosphere. This discrepancies are partly attributed to the oversimplified spacing of soil, soil contents and initial temperature fields, suggesting some improvement could probably be gained if the sub-grid scale nature of moisture and temperature fields was taken into account. However, IOA values for the wind field (0.62) as well as temperature field (0.78) is greater than the 'good' value criteria (> 0.5) implied by other studies. The good value of IOA along with relatively small wind field error in the near surface atmosphere implies that, on the basis of current meteorological data for initial fields, RAMS has good potentials to be used as a operational meteorological model in predicting the urban or local scale 3-dimensional wind fields for the dispersion forecast in association with hazardous chemical releases in Korea.

• 한국식품영양학회지
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• 제25권3호
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• pp.538-545
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• 2012

가공식품 제조 시 건더기 스프 및 조미 식품에 사용되고 채소류를 건조기 내부 반사 분산 기능을 가진 원적외선-진공 건조기와 열풍건조기를 이용하여 건조할 경우, 건조 조건에 따른 갈변도, 색도, 산도 및 pH 변화와 같은 이화학적 특성을 살펴보았으며, 수화복원성 및 전자현미경 관찰과 같은 물리적 특성을 알아보았다. 또한 총균수 측정에 따른 미생물학적 특성에 대한 건조 채소류들의 품질 변화를 알아보았다. 그 결과, 채소 원재료의 품질 저하 요소인 색의 변화 및 갈변도의 경우 RD-FRVD를 이용한 경우, HAD를 이용한 경우보다 색 및 갈변 현상이 적게 나타났다. 특히, 숙주의 경우에는 건조 전 상태와 갈변 정도가 크게 다르지 않게 나타났다. 산도 및 pH 측정 결과는 채소류의 수분함량 및 건조방법에 따라서 건조 전 상태보다 감소하는 경향을 나타내었으나 큰 유의차는 나타내지 않았다. 또한, 저장성을 위한 미생물 사멸 효과 역시 RD-FRVD를 이용하여 건조한 경우 총균수 사멸 효과가 있는 것으로 나타났다. 따라서 본 연구를 기초로 더 많은 건조 방법을 이용하여 원재료 채소 건조 시 품질저하 현상을 최소화 시킬 수 있는 건조방법에 대한 연구가 더욱 필요하며, 미생물에 대한 저장 안전성 및 영양성분 손실 최소화를 동시에 나타낼 수 있는 경제성 있는 건조방법이 건조 채소식품 이용이 급격히 증가하고 있는 현 식품 업체에 반드시 필요한 것으로 판단되었다.

• 한국환경과학회지
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• 제15권4호
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• pp.319-324
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• 2006

Release rate is one of the important items for the environmental impact assessment caused by radioactive materials in case of an accidental release from the nuclear facilities. In this study, the uncertainty of the estimated release rate is evaluated using Monte Carlo method. Gaussian plume model and linear programming are used for estimating the release rate of a source material. Tracer experiment is performed at the Yeoung-Kwang nuclear site to understand the dispersion characteristics. The optimized release rate was 1.56 times rather than the released source as a result of the linear programming to minimize the sum of square errors between the observed concentrations of the experiment and the calculated ones using Gaussian plume model. In the mean time, 95% confidence interval of the estimated release rate was from 1.41 to 2.53 times compared with the released rate as a result of the Monte Carlo simulation considering input variations of the Gaussian plume model. We confirm that this kind of the uncertainty evaluation for the source rate can support decision making appropriately in case of the radiological emergencies.

• Smart Structures and Systems
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• 제4권4호
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• pp.449-464
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• 2008

An array based, outward monitoring, ultrasonic guided wave based SHM technique using a single transmitter and multiple receivers (STMR), with a small footprint is discussed here. The previous implementation of such SHM arrays used a phase-reconstruction algorithm (that is similar to the beam-steering algorithm) for the imaging of reflectors. These algorithms were found to have a limitation during the imaging of defects/reflectors that are present in the "near-field" of the array. Here, the "near-field" is defined to be approximately 3-4 times the diameter of the compact array. This limitation is caused by approximations in the beam-steering reconstruction algorithm. In this paper, a migration-based reconstruction algorithm, with dispersion correction in the frequency domain, is discussed. Simulation and experimental studies are used to demonstrate that this algorithm improves the reconstruction in the "near-field" without decreasing the ability to reconstruct defects in the "far-field" in both isotropic and anisotropic plates.

• 한국조리학회지
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• 제4권
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• pp.167-187
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• 1998

The human resources play an important role in a hotel cooking department. The object of this study is to gain basic data for searching an effective human resources management method of cooking department in the hotel. To achieve this object, I proceeded like this. In the second chapter, I exerted myself to arrange the theoretical system on the content of the human resources management through an internal and external philological research. In the third chapter, I established conceptional research model to study factual research and three hypotheses. And I made all high-grade hotel cooking employee in Taegu and Kyung-Buk answer an questionnaire, so practiced interrelation analysis and dispersion analysis according to research hypothesis. The results are as follows. First, the result of hypothesis 1 was that three was rather a high interrelation between the human resources management factor of cooking department and its overall evaluation. Second, the result of hypothesis 2 was that three was a significant difference about the overall evaluation of cooking business management according to the position demographically. Third, the result of hypothesis 3 was that there was a significant difference according to the scholastic ability, position and the district of hotel in the demographical evaluation of human resources management factor. The limits of this study were that first, I defined the subject as the cook employee of high-grade hotel in Taegu and Kyung-Buk, second, I utilized partial variance among many variances affecting human resources management. Therefore after this study, these limits much be overcomed and multiple and scientific study must be accomplish. So human resources of cooking department in the hotel must improve more.

• 해양환경안전학회지
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• 제28권6호
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• pp.890-898
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• 2022

해상공사에서 발생하는 부유사는 해수의 탁도를 증가시키고 광량을 감소시켜 해양생물에 악영향을 미치므로 해양환경영향평가에서 중요한 요소이다. 하지만 평가에 적용되는 인자에 대한 공식적인 자료의 부족과 평가자의 능력에 따라 그 영향이 달리 평가되고 있다. 따라서 본 연구에서는 해역이용영향평가센터에서 검토한 3년간(2012-2014)의 매립, 준설, 외곽시설물 설치 등 총 58건 사업에 대한 부유사 확산 평가에 대한 실태를 진단하고 개선방안을 제시하였다. 개선방안 제시를 위해 4가지의 평가지표(격자체계의 적정성, 원단위의 적정성, 대표입경 및 침강속도의 적정성)를 적용하였다. 각 항목별 신뢰도에 평균점수 분석결과, 격자체계는 25점, 원단위는 60점, 대표입경은 34점 그리고 침강속도는 17점으로 평가항목에 대한 개선방안이 필요한 것으로 나타났다. 본 연구에서는 부유사 확산 평가상태에 대한 진단 및 신뢰도 평가 결과를 활용하여 부유사 확산예측에 대한 개선방안을 제안하였다. 먼저, 부유사 발생원단위 및 대표입경별 침강속도에 대한 공신력 있는 값이 가이드라인을 통해 제공해야 한다. 그리고 실무에선 신뢰성 향상을 위해 격자체계의 적정성과 결과의 검증을 철저히 해야 한다.

• 핵의학기술
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• 제16권2호
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• pp.99-105
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• 2012

Purpose : This study is designed to compare two parameters reflecting $^{18}F$-FDG uptake, SUV and radioactivity, for diagnosis of thyroid cancer in dual time $^{18}F$-FDG PET/CT imaging and to find which parameter is more useful to decide whether the tumor is malignant or not. Materials and Methods : We performed retrospective study for 40 patients. All patients are diagnosed as primary thyroid cancer and examined $^{18}F$-FDG PET/CT. First, we got the dispersion of scattering beam of neck and lung apex to set a background and compared each dispersion, mean value, standard deviation of maxSUV and radioactivity. Also, mean maxSUV, ${\Delta}maxSUV$, ${\Delta}maxBq$/ml(%) and radioactivity between groups according to lesion's size based on biopsy are compared with independent-sample t-test. Results : the values that were from maxSUV and radioactivity measurement technique were compensated and calculated to practical values for mean comparison and patients were divided to two groups based on tumor size, Group1 ($size{\leq}1$ cm, n=21), Group2 (size>1 cm, n=19) for accurate comparison. In Group1, maxSUV (semi-quantitative analysis) was increased from $5.64{\pm}5.85$ (1.89~17.84) at first image to $5.90{\pm}5.01$ (1.95~18.22) at second image and radioactivity (Bq/ml) (quantitative analysis) showed similar increase from $5.93{\pm}6.38$ (2.50~16.75) at first image to $6.01{\pm}5.25$ (2.66~16.58) at second image. In Group2, TFmaxSUV was $10.54{\pm}14.36$ (2.54~33.89) in true first image, TSmaxSUV was $9.85{\pm}12.88$ (2.62~26.20) in true second image separately. The maxSUV showed a significant difference in the mean comparison between the two groups (p=0.035) But, mean radioactivity (Bq/ml) was $5.93{\pm}6.38$ (4.81~40.99) in true first image, $6.01{\pm}5.25$ (4.51~36.93) in true second image and didn't show a significant difference statistically (p=0.126) Conclusion : In diagnosis of thyroid tumor, SUV and radioactivity depending on $^{18}F$-FDG uptake showed high similarity with coefficient of determination (R2=0.939) and malignant evaluation results using dual time also showed similar aspect. Radioactivity for evaluation of malignant tumor didn't show better specificity or sensitivity than maxSUV.

• 대한기계학회논문집A
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• 제26권11호
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• pp.2322-2327
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• 2002

The corrosion degradation characteristics of the 12Cr alloy steel, which is widely used in fossil power plants as a turbine blade material, are evaluated nondestructively by use of the backward radiated Rayleigh surface wave. In order to evaluate corrosion degradation characteristics, we constructed automated system for the backward radiation, and the frequency dependency of the Rayleigh surface wave is investigated indirectly by measuring the angular dependency of the backward radiation of the incident ultrasonic wave in the specimens. The velocity of the surface wave decrease as the increase of the aging time in the backward radiation profile, which seems to result from the increase of the effective degrading layer thickness. And, amplitude of the surface wave increase as the aging time, which seems to result from the increase of the intergranular corrosion. The result observed in this study demonstrates high potential of the backward radiated ultrasound as a tool for the nondestructive evaluation of the corrosion degradation characteristics of the aged materials.

• 한국안전학회지
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• 제27권4호
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• pp.76-82
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• 2012

A diesel-Liquefied natural gas(LNG) combustion engine truck fleet demonstration project had been carried out and commercial expansion project was launched. The key issues of these projects are the safety of LNG fuel station and the reduction of natural gas relief. When LNG is fueled to LNG vehicles the heat is input in the LNG system. The LNG in the fueling system was boiled and the vapor of LNG is vented through the safety devices. The temperature of the vapor of LNG is $-108^{\circ}C$ and density is heavier than air. It can be dispersed to downside of the fuel station. The safety evaluation is carried out using CFD program and risk assessment program for the vapor of LNG in the LNG vehicle fuel station. The hazards are identified and suggested the operation instruction to reduce the relief of LNG vapor.