• 한국물환경학회지
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• 제30권6호
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• pp.673-682
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• 2014

A watershed model was constructed using Hydrological Simulation Program Fortran to predict the water temperature at major tributaries of Nakdong River basin, Korea. Water temperature is one of the most fundamental indices used to determine the nature of an aquatic environment. Most processes of an aquatic environment such as saturation level of dissolved oxygen, the decay rate of organic matter, the growth rate of phytoplankton and zooplankton are affected by temperature. The heat flux to major reservoirs and tributaries was analyzed to simulate water temperature accurately using HSPF model. The annual mean heat flux of solar radiation was estimated to $150{\sim}165W/m^2$, longwave radiation to $-48{\sim}-113W/m^2$, evaporative heat loss to $-39{\sim}-115W/m^2$, sensible heat flux to $-13{\sim}-22W/m^2$, precipitation heat flux to $2{\sim}4W/m^2$, bed heat flux to $-24{\sim}22W/m^2$ respectively. The model was calibrated at major reservoir and tributaries for a three-year period (2008 to 2010). The deviation values (Dv) of water temperature ranged from -6.0 to 3.7%, Nash-Sutcliffe efficiency(NSE) of 0.88 to 0.95, root mean square error(RMSE) of $1.7{\sim}2.8^{\circ}C$. The operational water temperature forecasting results presented in this study were in good agreement with measured data and had a similar accuracy with model calibration results.

• 한국융합학회논문지
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• 제2권4호
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• pp.1-7
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• 2011

IT의 발전으로 기기 간 통신을 이용하는 M2M 시장이 급성장하고 있으며, 많은 기업들이 M2M 사업에 참여하고 있다. 본 논문에서는 텔레매틱스의 개념 및 차량 네트워크 보안의 취약성을 알아보았다. 차량 및 IT 기술의 융합과 이동통신망 기술의 발전은 사용자에게 제공되는 서비스의 질은 향상 시켰지만, 이로 인한 보안 위협은 다양해졌다. 텔레매틱스 사업에서 이동통신사업자의 참여로 생성될 수 있는 새로운 비즈니스 모델을 제시하였으며, 이러한 환경에서 발생 될 수 있는 차량 이동통신망 보안 취약성을 분석하였다. 이 중 발생할 수 있는 취약성을 해결하기 위한 방법으로 M2M 기기와 스마트폰 및 차량 상호 인증 기법을 제시하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.34-45
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• 2011

For the Hancheon drainage area in Jeju island, a groundwater flow model using Visual MODFLOW was developed to simulate artificial recharge through injection wells installed in the Hancheon reservoir. The model was used to analyze changes of the groundwater level and the water budget due to the artificial recharge. The model assumed that $2{\times}10^6m^3$ of storm water would recharge annually through the injection wells during the rainy season. The transient simulation results showed that the water level rose by 39.6 m at the nearest monitoring well and by 0.26 m at the well located 7 km downstream from the injection wells demonstrating a large extent of the affected area by the artificial recharge. It also shown that, at the time when the recharge ended in the 5th year, the water level increased by 81 m at the artificial reservoir and the radius of influence was about 2.1 km downstream toward the coast. The residence time of recharged groundwater was estimated to be no less than 5 years. The model also illustrated that 15 years of artificial recharge could increase the average linear velocity of groundwater up to 1540 m/yr, which showed 100 m/yr higher than before. Increase of groundwater storage due to artificial recharge was calculated to be $2.4{\times}10^6$ and $4.3{\times}10^6m^3$ at the end of the 5th and 10th years of artificial recharge, respectively. The rate of storage increase was gradually diminished afterwards, and storage increase of $5.0{\times}10^6m^3$ was retained after 15 years of artificial recharge. Conclusively, the artificial recharge system could augment $5.0{\times}10^6m^3$ of additional groundwater resources in the Hancheon area.

• 한국컴퓨터정보학회논문지
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• 제21권9호
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• pp.85-90
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• 2016

In this paper, we study the domain-independent sensor data structuring method and the derivations about ' Filter Criteria' expansion factors of heterogeneous domain systems. For this purpose, we propose a 5W1H based information search and retrieval method without knowledges about the target domains. And we also suggest a resource management model that can support expanding search of information. By the suggested method, the oneM2M standard able to implement the use-cases like 'data exchanging between the heterogeneous domains'.

• 대한토목학회논문집
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• 제41권5호
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• pp.505-512
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• 2021

침지형 자외선 살균조의 자외선 강도를 계산하기 위한 3차원 모델을 개발하였으며, 실제 하수처리장에 설치되어있는 개수로형 살균조와 관로형 살균조에 각각 적용하여 수치실험을 실시하였다. 모델링을 통해 계산한 살균조의 평균 자외선 강도는 각각 7.87 mW/cm²와 13.09 mW/cm²로 계산되었다. 자외선 조사 시간을 반영하고, 혼합 불균형, 램프 노화, 온도 및 파울링에 의한 감쇄효과를 고려한 자외선 조사량은 각각 21.1 mJ/cm², 24.8 mJ/cm²로 예측되었는데 이 값은 목표 자외선 조사량인 20 mJ/cm²보다 각각 5 %, 24 % 높은 것으로 예측되었다. 개발한 UV3D 모델을 사용하면 살균조의 조사 시간이나 램프의 출력을 높이지 않고도 수치실험을 통해 평균 자외선 강도가 가장 큰 최적의 램프 위치를 찾을 수 있다. 램프 위치 조정만으로 본 연구에서 적용한 개수로형 살균조와 관로형 살균조의 자외선 조사량은 각각 0.9 %, 0.5 % 향상시킬 수 있다. 개수로형 살균조의 경우 살균조의 체적은 그대로 유지하면서 가로와 세로의 비율을 조정하고, 램프의 위치를 바꾸면 평균 자외선 강도는 현재보다 7.4 % 더 증가한다.

• Asia pacific journal of information systems
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• 제31권2호
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• pp.141-184
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• 2021

While a great body of information systems (IS) literature has discussed mobile banking (m-banking) services, most of these studies have focused on the adoption or acceptance phases of this technology; with little attention was given to users' intension to continue using such technology. This paper aims at investigating the most important factors that predict users' continuous intension to use m-banking services in the post-adoption phase. This paper presents a conceptualization and validation of an extended expectation-confirmation model (ECM). A total of 303 Kuwaiti users of m-banking services participated in this study. Partial least squares (PLS) of structure equation modelling (SEM) technique was used to analyze the data. The results mainly showed that users' continuous intension to use m-banking services is significantly influenced by perceived trust, satisfaction, self-efficacy, performance expectancy and effort expectancy. Theoretical and practical contributions as well as the research limitations and future directions are discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1655-1659
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• 2008

Using numerical models, we investigated the efficiency of toxin removal using pulsatile flow in blood purification systems that use semipermeable membranes. The model consisted of a three-compartmental mass transfer model for the inside body and a solute kinetics model for the dialyzer. The model predicted the toxin concentration inside the body during blood purification therapy, and the toxin removal efficiencies at different flow configurations were compared quantitatively. According to the simulation results, the clearances of urea and ${\beta}_2$ microglobulin (B2M) using a pulsatile pump were improved by up to 30.9% for hemofiltration, with a 2.0% higher urea clearance and 4.6% higher B2M clearance for high flux dialysis, and a 3.9% higher urea clearance and 8.2% higher B2M clearance for hemodiafiltration. These results suggest that using a pulsatile blood pump in blood purification systems with a semipermeable membrane improves the efficacy of toxin removal, especially for large molecules and hemofiltration treatment.

• 설비공학논문집
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• 제7권4호
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• pp.681-693
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• 1995

A new set of capillary tube selection charts for R-22 is proposed. The set of charts takes into account of the roughness effect on the mass flow rate. For this purpose, a set of numerical model is developed and a series of experiments is conducted to verify the numerical model. A numerical model is used to calculated the mass flow rate for several sets of tube diameter, length, inlet pressures and degree of subcooling. The outlet of the tube is controlled to be at critical condition. The experimental flow rate is compared with calculated values. The calculated values are consistently less than the experimental ones except for the flow rate range below 40kg/hr. The deviation is within 10---. Based on the nunmerical model and results of experiments, the set of capillary tube selection charts for R-22 is constructed. The set of charts consists of standard capillary tube chart(L=2030mm, d=1.63mm, ${\varepsilon}=2.5{\mu}m$), non -standard flow factor(${\phi}_1$) chart, and non-standard roughness factor(${\phi}_2$) chart. The mass flow rate, flow factor, and the roughness factor are defined respectively as; $\dot{m}={\phi}_1{\phi}_2\dot{m}_{standard}\\{\phi}_1=\frac{\dot{m}(L,\;d,\;\varepsilon_{standard})}{\dot{m}_{standard}(L_{standard},\;d_{standard},\;{\varepsilon}_{standard})}\\{\phi}_2=\frac{\dot{m}(L_{standard},\;d_{standard},\;{\varepsilon})}{\dot{m}_{standard}(L_{standard},\;d_{standard},\;{\varepsilon}_{standard})}$.

• 터널과지하공간
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• 제20권5호
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• pp.369-377
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• 2010

근접굴착 시 기존터널의 안정성을 확보하는 방안을 연구하였다. 흙막이벽체의 수평변위가 생기지 않도록 선행하중을 가하였다. 이를 위해 선행하중을 가하지 않은 경우와 선행하중을 가한 경우에 대해 실대형 시험을 실시하였다. 지표면에 건물하중이 없는 경우와 건물하중이 있는 경우(0 m, 1D, 2D)에 대하여 각각 실험을 실시하였다. 그 결과 선행하중을 적용시켜 흙막이벽체의 변위를 억제시켰을때 벽체배면에 있는 기존터널의 안정성이 크게 향상되는 것을 확인할 수 있었다. 본 논문에서는 흙막이벽체와 기존터널의 거동에 대하여 연구하였다. 기존터널은 지름 12 m를 사용하였으며 1:10의 축척으로 2.0 m(폭) ${\times}$ 6 m(높이) ${\times}$ 4.0 m(길이)의 크기를 가진 대형토조에서 실험을 수행하였다.

• The Korean Journal of Pain
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• 제12권1호
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• pp.8-15
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• 1999

Following peripheral nerve injury, rats will show a tactile allodynia and hyperalgesia. But the mechanism of allodynia is still obscure. The present studies, using rats rendered allodynia by loosely constrictive ligation of the common sciatic nerve (Bennett Model) and tight ligation of L5 & L6 spinal nerve (Chung Model), aimed to investigate the changes of metabotrophic glutamate receptor type 5 on the development of tactile allodynia. Male Sprague-Dawley rats (130~200 g) were anesthetized with halothane, the rats were randomly divided into one of these three groups, Group 1 (Sham operation), Group 2 (Bennett model) and Group 3 (Chung model). Seven days after surgical procedure, the animal was reanesthetized and decapitated. The spinal cord was quickly removed and stored at deep freezer for polymerase chain reaction (RT-PCR). In Group 2&3, rats showed that tactile allodynia checked by up-down method with calibrated 8 von Frey hair. The level of gene expression of mGluR5 mRNA was significantly increased in group 2 and 3. These increases was significantly different from sham operation, group 1. It was also showed that the increasing patterns of group 2 and 3 in the gene expression were similar correlation with the results of the threshold for tactile allodynia on von Frey hair test. Even though there were some differences between Bennett model and Chung model, these results suggested that mGluR5 had partly attributed to making a tactile allodynia from these models.