• 한국농공학회지
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• 제23권3호
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• pp.88-95
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• 1981

This study was carried out to investigate the relation between seepage losses and flow section area in earth canals. Totally 77 seepage measurement was gained by ponded method and the tested canals belong to the irrigation area of Farmland Improvement Association in each province, Korea. The results obtained from this study may be used as a reasonable criteria for the estimation of canal seepage losses in the design of irrigation systems. Obtained results are summarized as follows: 1. Average seepage rates in each Soils is 14cm/day in ML, 6. 3cm/day in CL and 24.9 cm/day in SM. 2. Water depth and water surface width in eath canals have little influenced on the seepage rate, while the seepage losses was increased in proportion as the water surface width lengthens. 3. A formula of S=C.An defining a relationship between seepage losses and flow section was derieved as follows. ML:S=O. 35 VA 1.20 (m$^3$/day/m) CL:S=O. 13 VA 0.84 SM:s=O.67VA-1.56 4. The average seepage loss rates per 1km of canal are as followings. Measured Time ML CL SM 0-4 hrs 2.2% 0.6% 4.5% 4-2 4hrs 1.0% 0.15% 2.0% In above table we may obtain the following results. The first row is suitable for the canal having short delivery time of irrigation, while the second row for the canal having long delivery time.

• Kidney Research and Clinical Practice
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• 제37권4호
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• pp.338-346
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• 2018

Background: The most common cause of acute kidney injury (AKI) in pregnancy is preeclampsia. Serum cystatin C (CysC) is a potential biomarker of early kidney damage as its levels are not disturbed by volume status changes in pregnancy, and serum CysC levels could serve as a replacement for conventionally used creatinine. In this study, we investigated the serum levels of CysC in severe preeclampsia cases and the associations between CysC levels and poor obstetric outcomes. Methods: Our cohort included severe preeclampsia patients with a normal serum creatinine level. Creatinine was measured to calculate estimated glomerular filtration rate (eGFR) based on the Cockcroft and Gault, Modification of Diet in Renal Disease Study (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, while CysC was measured to calculated eGFR based on a CysC-based equation. We then evaluated the correlations between serum CysC level, eGFR, and obstetric outcomes. Results: Twenty-six patients were evaluated of which 38.5% delivered preterm and 30.8% had low-birth weight babies. Unlike creatinine-based eGFR and CysC-based eGFR, serum CysC demonstrate significant negative correlation with gestational age. Receiver operating characteristic curve analysis indicated that serum CysC is a potential biomarker of preterm delivery with a cut-off serum level of 1.48 mg/L with 80% sensitivity and 75% specificity. Conclusion: GFR estimation using CysC is likely to be inaccurate in pregnancy. However, we found a significant correlation between preterm delivery and serum CysC level. Our results suggest that serum CysC level has the potential to predict preterm delivery in severe preeclampsia patients.

• 한국전자통신학회논문지
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• 제17권4호
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• pp.687-694
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• 2022

본 논문에서는 Visual 동시적 위치추정 및 지도작성(SLAM : Simultaneous Localization and Mapping)기술을 응용하여 실내에서 생성된 SLAM 맵을 기반으로 지정된 목적지에 물건을 배달하는 자율주행 차량 플랫폼을 제안하였다. 실내에서 SLAM 맵을 생성하기 위해 소형 자율주행 차량 플랫폼의 상단에 SLAM 맵 생성을 위한 심도 카메라를 설치하고 SLAM 맵 속에서의 정확한 위치추정을 하기 위해 추적 카메라를 장착하여 구현하였다. 또한, 목적지의 표찰을 인식하기 위해 합성곱 신경망(CNN : Convolutional neural network)을 사용하여 목적지에 정확하게 도착할 수 있도록 주행 알고리즘을 적용하여 설계하였다. 실내 배송 자율주행 차량을 실제로 제작하였고 SLAM 맵의 정확도 확인과 CNN을 통한 목적지 표찰 인식 실험을 수행하였다. 결과적으로 표찰 인식의 성공률을 향상시켜 구현한 실내 배송용 자율주행 차량의 활용 적합성 여부를 확인하였다.

• 통상정보연구
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• 제18권2호
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• pp.27-51
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• 2016

본 연구의 목적은 우리나라 B2C 전자상거래 촉진요인과 온라인쇼핑시장 및 해외직접구매와의 상관관계를 분석함으로써 물류기업들의 물류운영전략 수립에 시사점을 제공하는데 있다. 본 연구는 문헌연구를 통하여 B2C 전자상거래 촉진요인을 도출하고, 전자상거래 촉진요인과 국내 온라인쇼핑 및 해외직접구매와의 인과관계를 실증 분석함으로써 B2C 전자상거래 시대 우리나라 택배서비스기업들의 과제 및 성공적 물류운영전략을 제안하고 있다. 본 연구에서는 B2C 전자상거래 촉진요인들이 국내 온라인쇼핑거래액 및 해외직접수입 실적에 미치는 영향을 파악하기 위해 두 가지 ARDL 모형을 설정하였다. 모형의 분석결과, 신용카드 이용건수, 가구당 처분가능소득, 환율, 실질GDP, 정보통신 부문 설비투자, 초고속인터넷가입자수, 인터넷 프로토콜 IPV4 보유수, 15세 이상 인구 등의 변수가 종속변수에 영향을 미치는 것으로 나타났다. 향후 온라인 모바일 기술 및 국민들의 경제수준이 고양됨에 따라 B2C 전자상거래 기업 및 물류기업들은 최적의 택배 물류서비스 수행을 위한 고도의 전략적 접근이 필요한 시점이다.

• 간호행정학회지
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• 제3권2호
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• pp.151-165
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• 1997

A cost analysis for hospitalized patients was performed based on the KDRG classification in order to determine an appropriate nursing fee under the PPS(Prospective Payment System). The data was collected from 20 nursing units of three tertiary hospitals and two secondary hospitals from August 26 to September 15, 1996. The study consisted of 148 inpatients diagnosed for lens procedures(KDRG 03900), tonsillectomy &/or adenoidectomy(KDRG 16100), Cesarean section(KDRG 37000), or vaginal delivery(KDRG 37300) without any complications. The direct or indirect nursing hours of each patients were measured. Then, direct or indirect nursing expenditures of four nursing units, operating room and delivery room were computed. Finally, the resources used including average total nursing hours, average length of stay and average nursing cost of each KDRG were estimated as follows; 1) The average total nursing hours were 640 minutes for lens procedures, 403 minutes for tonsillectomy &/or adenoidectomy, 934 minutes for appendectomy with complicated principal diagnosis, 1,094 minutes for Cesarean section and 631 minutes for vaginal delivery. Significant differences were found in average total nursing hours among hospitals. 2) The average length of stay in lens procedures were 5 days, 4 days for tonsillectomy &/or adenoidectomy, 6 days for appendectomy with complicated principal diagnosis, 8 days for Cesarean section and 3 days for vaginal delivery. All results were within normal determined by the Ministry of Health and Welfare although significant differences existed among hospitals, especially with average length of stay for leng procedures between tertiary hospitals and secondary hospitals which was greater than for those of others. 3) The average nursing cost were 87,146 Won for lens procedures, 69,600 Won for tonsillectomy &/or adenoidectomy, 128,337 Won for appendectomy with complicated principal diagnosis, 151,769 Won for Cesarean section and 85,403 Won for vaginal delivery. These costs were 7.6%, 13.0%, 13.0%, 16.0% and 22.0%, respectively, of the official price fixed by the Ministry of Health and Welfare under the prospective payment system. Research for the analysis of nursing costs according to the severity of illness for those KDRGs shoud be carried out within the period of the PPS pilot project. In addition, a proper nursing fee schedule for a new reimbursement system based upon the result of the above research should be prepared in the near future.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권3호
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• pp.52-64
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• 2020

The universal soil loss equation (USLE), a model for estimating the potential soil loss, has been used not only in research areas but also in establishing national policies in South Korea. Despite its wide applicability, USLE cannot adequately address the effect of seasonal variances. To overcome this limit, the ArcGIS-based Sediment Assessment Tool for Effective Erosion (ArcSATEEC) has been developed as an alternative model. Although the field-scale (< 100 ㎡) application of this model produced reliable estimation results, it is still challenging to validate accuracy of the model estimation because it only estimates potential soil losses, not the actual sediment yield. Therefore, in this study, a method for estimating actual soil loss based on the ArcSATEEC model was suggested. The model was applied to eight watersheds in South Korea to estimate sediment yields. Correction factor was introduced for each watershed, and the estimated sediment yield was compared with that of the estimated yield by LOAD ESTimator (LOADEST). Sediment yield estimation for all watersheds exhibited reliable results, and the validity of the proposed correction factor was confirmed, suggesting the correction factor needs to be considered in estimating actual soil loss.

• Journal of electromagnetic engineering and science
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• 제13권4호
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• pp.233-239
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• 2013

This paper proposes an accurate approach for predicting transferred power from a noise source to integrated circuits based on the characteristics of the power transfer network. A power delivery trace on a package and a printed circuit board are designed to transmit power from an external source to integrated circuits. The power is demonstrated between an injection terminal on the edge of the printed circuit board and integrated circuits, and the power transfer function of the power distribution network is derived. A two-tier calibration is applied to the test, and scattering parameters of the network are measured for the calculation of the power transfer function. After testing to obtain the indispensable parameters, the real received and tolerable power of the integrated circuits can be easily achieved. Our proposed estimation method is an enhancement of the existing the International Electrotechnical Commission standard for precise prediction of the electromagnetic immunity of integrated circuits.

• 한국건설관리학회논문집
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• 제7권4호
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• pp.177-183
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• 2006

Risk-based estimation has been successfully introduced into the construction industry. By incorporating historical data associated with probability analysis, risk-based estimate is an effective decision support aid in considering whether to launch a particular project. The industry challenges, however, especially related with management issues, such as labor shortage, wage growth, and supply chain complexity, have often resulted in poor cost performance. The insufficient assessing the project characteristics (i.e., resource availability, project complexity, and project delivery method) can be the main reasons in the poor cost performance. Because the accuracy level of cost performance prediction can be enhanced by extensive evaluation of the subject project characteristics, a new approach for predicting cost performance in an earlier stage of a project can improve the Industry substantiality, in other words, value maximization. The purpose of this paper is to develop a new methodology in developing a risk-based estimate tool by incorporating extensive project characteristics. To do this, an extensive industry survey was conducted from both private and public sectors in building industry in Korea. In addition, significant project characteristics were identified in terms of cost performance indicator. Although the data collection is limited to Korean industry the suggested approach provides the industry with a straightforward methodology in risk management. As many researchers maintained that front-end planning efforts are crucial in achieving the successful outcome in building projects, the new method for risk-based estimation can Improve the cost performance as well as enhance the fulfillment in terms of business sustainability.

• 환경영향평가
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• 제23권5호
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• pp.393-405
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• 2014

본 연구에서는 권역별 수질평가 및 비점오염원 배출부하량을 산정하여, 낙동강수계 권역별 비점 오염원 오염도를 평가하고, 우선관리유역 선정 및 향후 관리방향을 설정하였다. 낙동강수계 수질평가를 실시한 결과, 중권역별 BOD농도를 기준으로 Ia등급에 해당하는 중권역이 10개, Ib등급이 6개, II등급이 5개, III등급이 1개 중권역에 해당하는 것으로 나타났다. COD 농도의 경우, Ib등급에 해당하는 중권역이 9개, II등급이 6개, III등급이 6개, IV등급이 1개 중권역에 해당하는 것으로 나타났다. 중권역 내 수질 오염도를 검토하여 오염도 순위를 적용하는 기준으로 하였으며, 그 결과 금호강 중권역, 낙동고령 중권역, 낙동밀양 중권역 및 남강 중권역이 선정되었다. 중권역별 토지계 원단위를 활용하여 비점오염원 배출부하량을 산정한 결과, 가장 많은 비점오염부하량을 배출하는 중권역은 금호강 중권역 으로 17,706.7 kg/day로 나타났다. 낙동강수계 비점오염원에 대한 수질평가 및 부하량 산정 결과 금호강중권역에 대한 비점오염원 관리가 가장 우선시 되어야 함을 알 수 있었다.

• 한국통신학회논문지
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• 제30권10C호
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• pp.1036-1043
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• 2005

본 논문에서는 H.264 표준 동영상 부호화 방식을 위한 순차적 움직임 벡터 오류 은닉 기법에 대해 제안한다. H.264 표준 동영상 부호화 방식에서의 움직임 예측과정은 다양한 크기의 서브 매크로 블록 모드에 따라 각기 다른 움직임 벡터 개수를 갖게 되고, 이로 인해 움직임 벡터는 기존의 표준 부호화 방식에 비해 상대적으로 적은 영역을 대표하게 된다. 그러므로 이웃한 블록의 움직임 벡터간의 상관관계는 서브 매크로 블록의 크기가 작을수록 더 커지게 된다. 제안 방식에서는 변화된 국부 통계 특성에 대한 적응도에 따른 $\alpha$-trimmed mean 필터를 이용하여 움직임 벡터를 순차적으로 복구하는 움직임 벡터 오류 은닉기법에 대해 제안한다. 실험 결과를 통해 제안한 방식이 실시간 동영상 전송에 적합하며 기존의 블록 경계 정합 방식 및 라그랑즈 보간 방식과 유사한 성능을 보임을 확인할 수 있었다.