• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.121-126
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• 2018

The oral hygiene of patients admitted to the ICU (Intensive Care Unit) is very important. Critically ill patients are basically immunocompromised ones because of the high risk of infection by various pathogenic bacteria. The mouth is not only the primary site of infection, but also the site of systemic infections. The purpose of this study was to design a mouthpiece type vacuum oral cleaner for the oral care of seriously ill patients. A 3D CAD modeling and flow analysis model were established for a double structure type cleaner and standard tooth model, and their pressure and flow characteristics were analyzed. The pressure inside the oral cleaner was almost constant, but the velocity distribution showed a large difference between the inside and outside of the teeth. The velocity at the center region inside of the teeth was the highest, and the speed decreased as the distance from the center increased. In the analysis of the case where the suction tube was replaced by the drainage tube, the velocity at the center of the outer portion of the teeth was the highest. In order to increase the effectiveness of the oral cleaner, alternating between suction and drainage is proposed, and a design complement to increase the speed of the molar region is required.

• Journal of the Korean Society for Railway
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• v.13 no.1
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• pp.71-77
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• 2010

It is increasing annually that the cost for bridge Maintenance Repair & Rehabilitation (MR&R) in developed countries. Based on Intelligent Technology, Bridge Management System (BMS) is developed for optimization of Life Cycle Cost (LCC) and reliability to predict long-term bridge deteriorations. However, such data are very limited amongst all the known bridge agencies, making it difficult to reliably predict future structural performances. To alleviate this problem, an Artificial Neural Network (ANN) based Backward Prediction Model (BPM) for generating missing historical condition ratings has been developed. Its reliability has been verified using existing condition ratings from the Maryland Department of Transportation, USA. The function of the BPM is to establish the correlations between the known condition ratings and such non-bridge factors as climate and traffic volumes, which can then be used to obtain the bridge condition ratings of the missing years. Since the non-bridge factors used in the BPM can influence the variation of the bridge condition ratings, well-selected non-bridge factors are critical for the BPM to function effectively based on the minimized discrepancy rate between the BPM prediction result and existing data (deck; 6.68%, superstructure; 6.61%, substructure; 7.52%). This research is on the generation of usable historical data using Artificial Intelligence techniques to reliably predict future bridge deterioration. The outcomes (Long-term Bridge deterioration Prediction) will help bridge authorities to effectively plan maintenance strategies for obtaining the maximum benefit with limited funds.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.853-860
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• 2022

The purpose of this study is to suggest an improvement plan for the calculation method of the engineer standard wage rate (ESWR) and to compute a reasonable ESWR. To this end, an adequacy review of theESWR calculation criteria was conducted along with an extensive engineering industry survey. The survey results were analyzed using an effective response sample of 748 companies out of 1,000 survey samples extracted by stratifying the 5,879 survey population. The main results were as follows. ①When calculating the engineering service fee, the prime contractor's engineer wage is suitable for the ESWR. The ESWR can be estimated by the formula 'average wage÷[1-proportion of subcontract orders×(1-subcontract rate)].' ② The field survey showed that the number of monthly working days was 20.35-20.54 days at 99 % confidence interval, which was significantly different from the current standard (22 days). In addition, as a result of a legal review of the ESWR criteria, it was found that the number of working days should be calculated in accordance with the Labor Standards Act after 2022. ③ Applying government guidelines, the time difference between the wage survey and the ESWR application can be corrected by the past ESWR increase rate for a specific period. ④ Using modeling based on the analysis above, the current ESWR was 13.5-14.5 % lower than the appropriate level. A lower ESWR was driven by the non-reflection of subcontract structure (4.1 %), overestimation of monthly work days (6.8-7.8 %), and application of past wage (2.6 %). The proposed model is expected to be widely used in policy making, as it can provide a useful framework for calculating the standard wage rate in similar industries as well as calculating appropriate engineering fees.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.299-308
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• 2002

In horse, a single gene encodes both eCG and eLH $\beta$ subunits. The difference between eCG and eLH lies in the structure of their glycoresidues, which are both sialylated and sulfated in LH and sialylated in CG eCG consists of highly glycosyiated $\alpha$- and $\beta$-subunits and is an unique member of the gonadotropin family because it elicits response characteristics of both FSH and LH in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of gonadotropin structure-function relationships and the understanding of the molecular bases of the specific interactions of these hormones with their receptors. Thus, eCG is a dintinct molecule from the view points of its biological function and glycoresidue structures. The oligosaccharide at Asn 56 of the $\alpha$-subunit plays an indispensable role, whereas the carboxyl-terminal extension of the eCG $\beta$-subunit with its associated O-linked oligosaccharides is not improtant for, the in vitro LH-like activity of eCG. In contrast, both N- and O-linked oligosaccharides play important roles for FSH-like activity and increase FSH-like activity by removal of N- and O-linked oligosaccharides. Therefore, the dual LH- and FSH-like activities of eCG can be clearly separated by removal of either the N-linked oligosaccharide on the $\alpha$-subunit or CTP-associated O-linked oligosaccharides from its $\beta$-subunit. The glycoresidues seem to play crucial roles fer biological activities. The tethered-eCG was effciently secreted and showed similar LH-like activity to the dimeric eCG $\alpha$/ $\beta$ and native eCG. FSH-like activity of the tethered-eCG was also shown similarly in comparison with the native and wild type eCG $\alpha$/ $\beta$. Our data for the first time suggest that the tethered-eCG can be expressed efficiently and the produced product by the CHO-Kl cells is fully LH- and FSH-like activities in rat in vitro bioassay system. Our results also suggest that this molecular can imply particular models ot FSH-like activity not LH-like activity in the eCG. Taken together, these data indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion.

• Journal of Chest Surgery
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• v.38 no.2 s.247
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• pp.101-109
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• 2005

Background: In sudden cardiac arrest, the effective maintenance of coronary artery blood flow is of paramount importance for myocardial preservation as well as cardiac recovery and patient survival. The purpose of this study was to directly compare the effects of pulsatile and non-pulsatile circulation to coronary artery flow and myocardial preservation in cardiac arrest condition. Material and Method: A cardiopulmonary bypass circuit was constructed in a ventricular fibrillation model using fourteen Yorkshire swine weighing $25\~35$ kg each. The animals were randomly assigned to group I (n=7, non-pulsatile centrifugal pump) or group II (n=7, pulsatile T-PLS pump). Extra-corporeal circulation was maintained for two hours at a pump flow of 2 L/min. The left anterior descending coronary artery flow was measured with an ultrasonic coronary artery flow measurement system at baseline (before bypass) and at every 20 minutes after bypass. Serologic parameters were collected simultaneously at baseline, 1 hour, and 2 hours after bypass in the coronary sinus venous blood. The Mann-Whitney U test of STATISTICA 6.0 was used to determine intergroup significances using a p value of < 0.05. Result: The resistance index of the coronary artery was lower in group II and the difference was significant at 40 min, 80 min, 100 min and 120 min (p < 0.05). The mean velocity of the coronary artery was higher in group II throughout the study, and the difference was significant from 20 min after starting the pump (p < 0.05). The coronary artery blood flow was higher in group II throughout the study, and the difference was significant from 40 min to 120 min (p < 0.05) except at 80 min. Serologic parameters showed no differences between the groups at 1 hour and 2 hours after bypass in the coronary sinus blood. Conclusion: In cardiac arrest condition, pulsatile extracorporeal circulation provides more blood flow, higher flow velocity and less resistance to coronary artery than non-pulsatile circulation.

• Journal of the Korean Geographical Society
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• v.51 no.4
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• pp.509-523
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• 2016

The soil prediction can provide quantitative soil information for sustainable mountainous ecosystem management. Visible near infrared spectroscopy, one of soil prediction methods, has been applied to predict several soil properties with effective costs, rapid and nondesctructive analysis, and satisfactory accuracy. Spectral preprocessing is a essential procedure to correct noisy spectra for visible near infrared spectroscopy. However, there are no attempts to evaluate various spectral preprocessing methods. We tested 5 different pretreatments, namely continuum removal, Savitzky-Golay filter, discrete wavelet transform, 1st derivative, and 2nd derivative to predict soil carbon(C) and nitrogen(N). Partial least squares regression was used for the prediction method. The total of 153 soil samples was split into 122 samples for calibration and 31 samples for validation. In the all range, absorption was increased with increasing C contents. Specifically, the visible region (650nm and 700nm) showed high values of the correlation coefficient with soil C and N contents. For spectral preprocessing methods, continuum removal had the highest prediction accuracy(Root Mean Square Error) for C(9.53mg/g) and N(0.79mg/g). Therefore, continuum removal was selected as the best preprocessing method. Additionally, there were no distinct differences between Savitzky-Golay filter and discrete wavelet transform for visual assessment and the methods showed similar validation results. According to the results, we also recommended Savitzky-Golay filter that is a simple pre-treatment with continuum removal.

• Journal of Astronomy and Space Sciences
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• v.11 no.1
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• pp.71-80
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• 1994

It is generally known that the measurement of the ionospheric total electron content(TEC) by GPS can more accurately monitor the broader area of the ionosphere than other current methods. \Ve measured the TEC along a slant path considering the arrival time differences of P-code which is transmitted from GPS satellites with the modulation on two L-band carrier frequencies, L1 (1574.42MHz) and L2 (1227.60MHz). Under the assumptions that the ionosphere is uniformly distributed and its average height is 350km, we transformed the slant TEC to the vertical TEC at the point that the line-of-sight direction to GPS satellite cut across the average height of the ionosphere. Because there is no dual frequency P-code GPS receiver in Korea, we used the data observed at the TAIW GPS station ($N25^{\circ},E121.5^{\circ}$) in Taiwan which is one of the core stations in International GPS and Geodynamics Services (IGS). The TEC values obtained in this work showed a typical daily variation of the ionosphere which is high in the daytime and low in the nighttime. Our results are found to be consistent with the SOLAR-DAILY data of NOAA and the Klobuchar's model for the ionospheric correction of GPS. In addition, in the cornparision with SOLAR-DAILY data, we estimated the precision of our TEC measurement as 2 TEC.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.199-199
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• 2013

최근 단파장 광전 소자와 고출력 고주파 전자 소자에 대한 수요 때문에 넓은 밴드갭 에너지를 갖는 반도체에 관심이 많다. 이중에서, ZnO는 우수한 화학 및 역학적 안정성, 수소 플라즈마 내구성과 저가 제조의 장점 때문에 광전자 소자 개발 분야에 적합한 산화물 투명 전극으로 관심을 끌고 있다. 불순물이 도핑되지 않은 ZnO는 본질적으로 산소 빈자리 (vacancy)와 아연 격자틈새 (interstitial)와 같은 자체의 결함으로 말미암아 n형의 극성을 갖기 때문에, 반도체 소자로 응용하기 위해서는 도핑 운반자의 농도와 전도성을 제어하는 것이 필요하다. 본 연구에서는 박막 제조시 제어성, 안정성과 용이하게 성장이 가능한 졸겔 (sol-gel) 방법을 사용하여 사파이어와 석영 기판 위에 Cu가 도핑된 ZnO 박막을 성장시켰으며, 그것의 구조, 표면 형상, 평균 투과율, 광학 밴드갭 에너지를 계산하였다. 특히, Cu의 몰 비를 0, 0.01, 0.03, 0.05, 0.07, 0.1 mol로 변화시키면서 ZnO:Cu 박막을 성장시켰다. ZnO:Cu 졸은 zinc acetate dihydrate, 2-methoxyethanol (용매), momoethanolamine (MEA, 안정제)을 사용하여 제조하였다. 상온에서 2-methoxyethanol과 MEA가 혼합된 용액에 zinc acetate dihydrate (Zn)을 용해시켰다. 이때 MEA와 Zn의 몰 비는 1로 유지하였다. 이 용액을 $60^{\circ}C$ 가열판 (hot plate)에서 24 h 동안 자석으로 휘젓으며 혼합하여 맑고 균일한 용액을 얻었다. 이 용액을 3000 rpm 속도로 회전하는 스핀 코터기의 상부에 장착된 사파이어와 석영 기판 위에 주사기 (syringe)를 사용하여 한 방울 떨어뜨려 30 s 동안 스핀한 다음에, 용매를 증발시키고 유기물 찌꺼기를 제거하기 위하여 $300^{\circ}C$에서 10분 동안 건조시킨다. 기판 위에 코팅하는 작업에서 부터 건조 작업까지를 10회 반복한 다음에, 1 h 동안 전기로에 장입하여 석영 기판 위에 증착된 시료는 $550^{\circ}C$에서, 사파이어 기판은 $700^{\circ}C$에서 열처리를 수행하였다. Cu의 몰 비 0, 0.01, 0.03, 0.05, 0.07, 1로 성장된 ZnO:Cu 박막에 대한 x선 회절 분석의 결과에 의하면, 모든 ZnO:Cu 박막의 경우에 관측된 34.3o의 피크는 ZnO (002) 면에서 발생된 회절 패턴을 나타낸다. 이것은 JCPDS #80-0075에 제시된 회절상과 일치하였으며, ZnO:Cu 박막이 기판에 수직인 c-축을 따라 우선 배향됨을 나타낸다. 사파이어 기판 위에 증착된 박막의 경우에, Cu의 몰 비가 점점 증가함에 따라(002)면 회절 피크의 세기는 전반적으로 증가하여 0.07 mol에서 최대를 나타내었으나, 석영 기판 위에 증착된 박막의 경우에는 0.05 mol에서 최대를 보였다. 외선-가시광 분광계를 사용하여 서로 다른 Cu의 몰 비로 성장된 ZnO:Cu 박막에서 광학 흡수율 (absorbance) 스펙트럼을 측정하였으며, 이 데이터를 사용하여 평균 투과율을 계산한 결과, 투과율은 Cu의 몰 비에 따라 현저한 차이를 나타내었다. Cu의 몰 비가 0.07 mol일 때 평균 투과율은 80%로 가장 높았으며, 0.03 mol에서는 30%로 최소이었다. 광학밴드갭 에너지는 Tauc 모델을 사용하여 계산하였고, 결정 입자의 형상과 크기와의 상관 관계를 조사하였다.

• Food Science and Industry
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• v.40 no.2
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• pp.46-58
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• 2007

제2형 당뇨병은 대사성 질환으로 간, 근육 그리고 지방 조직 세포에서 인슐린 작용의 장애로 나타나는 인슐린 저항성으로 혈당의 이용이 감소하여 혈당이 높아짐에도 불구하고 췌장의 베타세포에서 인슐린 분비가 충분하지 못할 때 유발된다. 서구에서는 비만 등으로 인해 인슐린 저항성이 증가하면 인슐린 분비가 높은 고인슐린혈증을 나타내어 당뇨병으로의 진전은 늦다. 하지만 우리나라를 비롯한 아시아의 사람들은 인슐린 저항성이 증가할 때 인슐린 분비가 충분치 못해 혈청 인슐린 농도가 정상인과 비슷하거나 더 낮은 상태에서 당뇨병으로 진전된다. 이러한 차이는 우리나라를 비롯한 아시아 사람들에게서 제2형 당뇨병의 발생이 급격하게 증가할 것이라는 보고되었다. 결국 당뇨병은 간, 근육 및 지방조직에서의 인슐린 작용의 장애와 췌장의 베타세포에서 인슐린 분비의 부족의 복합적인 장애에 의해서 나타나고 이것은 공통적으로 각 조직에서의 인슐린/insulin growth factor (IGF)-1 신호전달의 장애와 관련이 있다. 베타세포에서의 인슐린분비 자체는 인슐린/IGF-1 신호전달과 관계가 없지만 간접적으로 관련이 있다. 인슐린 분비능은 베타세포의 증식과 생존에 의한 베타세포의 양과 밀접한 관련이 있는데 인슐린/IGF-1 신호전달은 베타세포의 증식과 생존을 조절한다. 그러므로 혈당 조절에 관여하는 기능성 식품은 인슐린 작용을 향상시키는 인슐린 민감성 특성을 가지거나, 혈당이 높아질 때 인슐린 분비를 촉진시키는 insulinotropic 작용을 하는 성질을 가지고 있어야 하겠다. 전자의 대표적인 약은 1999년에 미국 FDA에서 승인 받은 peroxisome proliferator-activated receptor $(PPAR)-{\gamma}$ agonist 인 thiazolidinedione 계통의 약물인 troglitazone, pioglitazone, rosiglitazone 등이 있고, 후자는 2007년에 승인 받은 Exenatide는 glucagon like peptide (GLP)-1 agonist이다. 이 두 가지 약은 모두 자연계에 존재하는 동식물에서 유래된 것으로 식품에도 많이 다양한 종류의 인슐린 민감성 물질이나 insulinotropic 작용을 하는 물질이 함유되어 있을 것이다. 이러한 기능 이외에 혈당조절 약이나 식품으로 사용되는 것은 탄수화물의 소화를 방해하는 것으로 탄수화물 소화효소인 a-amylase 또는 maltase의 활성을 억제하여 식후 혈당의 급격한 상승을 방지하는 것이 있다. 우리나라 사람들은 탄수화물의 섭취가 너무 많아서 실제로 이러한 식품이나 약의 효능이 높지 않을 것이다. 혈당을 조절하는 기능성 식품은 이 세 가지 효능 중 일부를 가지고 있는 것이 될 수 있다. 이러한 기능을 스크리닝하기 위해서 3가지 단계를 거쳐야 한다. 먼저 시험관에서 또는 세포 실험을 통해서 앞서 언급한 3가지 기능을 가지고 있는 지 여부를 각각 조사한다. 이중에서 효과가 있는 것은 당뇨 동물 모델을 사용하여 in vivo에서 혈당 강하기능과 혈당 강하기전을 조사하는 실험을 한다. 효과가 있는 식품이 우리가 전통적으로 식품으로 섭취해 왔다면 독성 검사를 거쳐야 할 필요가 없지만 한약재이거나 특수 식품의 경우에는 in vivo 실험 전에 GLP 기관에서 반드시 독성 실험을 거쳐 독성 유무를 확인할 필요가 있다. 동물 실험에서 효과적인 것은 인체 실험을 거쳐 혈당 조절 기능성 식품으로 식약청에서 허가를 받을 수 있겠다. 결론적으로 식품에는 항당뇨 특성을 가진 물질들이 함유되어 있는 것들이 상당히 많다. 혈당 조절기능이 있는 기능성 식품으로 개발할 때 고려해야 할 것은 1) 그 양이 혈당 강하 기능성 식품으로 지정받을 수 있을 정도로 충분히 함유되어 있느냐, 2) 혈당을 강하시키는 기전이 단순히 당의 배설을 촉진시켜서 혈당을 저하시키는 것이 아니라, 인슐린 작용을 촉진시키거나, 포도당 자극에 의한 인슐린 분비를 촉진시키거나 탄수화물의 소화 흡수를 억제시킴으로 혈당을 강하시키는 지 등을 파악하는 것이다. 이러한 조건을 만족시키는 식품은 지속적으로 섭취할 때 당뇨병을 예방하거나 진전을 지연시킬 수 있는 혈당조절기능이 있는 기능성 식품으로 개발 가능성이 있겠다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.222-232
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• 2022

In this study we investigated the characteristics of long-term tidal constituents based on 30 tidal gauge data along the coasts of Korea and its the effects on total water level (TWL) forecasts. The results show that the solar annual (Sa) and semiannual (Ssa) tides were dominant among long-term tidal constituents, and they are relatively large in western coast of Korea peninsula. To investigate the effect of long-term tidal constituents on TWL forecasts, we produced predicted tides in 2021 with and without long-term tidal constituents. The TWL forecasts with and without long-term tidal constituents are then calculated by adding surge forecasts into predicted tides. Comparing with the TWL without long-term tidal constituents, the results with long-term tidal constituents reveals small bias in summer and relatively large negative bias in winter. It is concluded that the large error found in winter generally caused by double-counting of meteorological factors in predicted tides and surge forecasts. The predicted surge for 2021 based on the harmonic analysis shows seasonality, and it reduces the large negative bias shown in winter when it subtracted from the TWL forecasts with long-term tidal constituents.