• Journal of The Korean Association of Information Education
• /
• v.12 no.2
• /
• pp.235-244
• /
• 2008

According to develop the computer and communication technology, recently educational environment is growing to ubiquitous learning with direction which select the studying content, studying time and a studying order oneself. In order to raise effect of studying in the ubiquitous learning(u-Learning), the help or advice of the specialist is necessary earnestly. Accordingly, if it will combine the scaffolding and the mentoring in the u-Learning, a studying effect will be maximize. This paper design the u-SM(Scaffolding and Mentoring) teaching and learning model which applies the scaffolding and e-mentoring. In addition, it embodies and applies the designed u-SM model. Then it examines it affects in studying achievements and attitudes of students and verifies the application possibility of the u-SM teaching and learning.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.29 no.2
• /
• pp.31-36
• /
• 2006

대기행렬 모형은 통신시스템이나 통신망 구현에 가장 적합한 수리모형으로 알려져 있고, 이에 대한 연구가 상당히 많이 진행되고 있다. 본 논문에서는 재해가 발생될 수 있는 BMAP/SM/1 대기시스템으로, 재해가 발생했을 경우 시스템 복구가 즉시 이루어지지 않고 임의 시간 후 복구 되는 시스템을 고려대상으로 하고 있다. 시스템의 정보입력흐름은 상호종속 또는 그룹 입력이 허용되는 배치마코프 도착과정으로 가정하였고, 또한 서비스분포는 세미 마코프 프로세스를 따른다고 가정하였다. 아울러 시스템에 재해가 발생하면 모든 고객은 즉시 시스템을 떠나게 되고, 재해복구는 임의 시간 후에 이루어진다. 임베디드 마코프체인의 안전상태 확률분포가 유도를 위한 정상 알고리즘 개발이 이루어졌다.

• Journal of Korean Society of Forest Science
• /
• v.110 no.3
• /
• pp.322-340
• /
• 2021

Due to climate change and its consequential spring temperature rise, flowering time of Robinia pseudoacacia has advanced and a simultaneous blooming phenomenon occurred in different regions in South Korea. These changes in flowering time became a major crisis in the domestic beekeeping industry and the demand for accurate prediction of flowering time for R. pseudoacacia is increasing. In this study, we developed and compared performance of four different models predicting flowering time of R. pseudoacacia for the entire country: a Single Model for the country (SM), Modified Single Model (MSM) using correction factors derived from SM, Group Model (GM) estimating parameters for each region, and Local Model (LM) estimating parameters for each site. To achieve this goal, the bloom date data observed at 26 points across the country for the past 12 years (2006-2017) and daily temperature data were used. As a result, bloom dates for the north central region, where spring temperature increase was more than two-fold higher than southern regions, have advanced and the differences compared with the southwest region decreased by 0.7098 days per year (p-value=0.0417). Model comparisons showed MSM and LM performed better than the other models, as shown by 24% and 15% lower RMSE than SM, respectively. Furthermore, validation with 16 additional sites for 4 years revealed co-krigging of LM showed better performance than expansion of MSM for the entire nation (RMSE: p-value=0.0118, Bias: p-value=0.0471). This study improved predictions of bloom dates for R. pseudoacacia and proposed methods for reliable expansion to the entire nation.

• Korean journal of applied entomology
• /
• v.56 no.1
• /
• pp.1-18
• /
• 2017

Temperature-dependent development model is an essential component for forecasting models of insect pests as well as for insect population models. This study reviewed the nonlinear models which explain the relationship between temperature and development rate of insects. In the present study, the types of models were classified largely into empirical and biophysical model, and the groups were subdivided into subgroups according to the similarity of mathematical equations or the connection with original idea. Empirical models that apply analytical functions describing the suitable shape of development curve were subdivided into multiple subgroups as Stinner-based types, Logan-based types, performance models and Beta distribution types. Biophysical models based on enzyme kinetic reaction were grouped as monophyletic group leading to Eyring-model, SM-model, SS-mode, and SSI-model. Finally, we described the historical development and characteristics of non-linear development models and discussed the availability of models.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.5 no.3 s.18
• /
• pp.73-82
• /
• 2005

The scheme for the conveyance increasement of urban river is presented in this study. For the use of the lower part of the road paralleled to urban river as a conveyance, the 2-dimensional flood flow between main channel and added conveyance section is analyzed by mathematical model SMS(2-D simulation model). The result of the HEC-RAS(1-D simulation model) is used to calibrate the parameters of SMS. New scheme is applied to the Cheonggeyecheon Restoration Project. The capacity of flood flow between main channel and added conveyance is simulated for 50, 80, 200 year frequency flood and suitable size of pathway is proposed.

• Journal of the Korean Geosynthetics Society
• /
• v.7 no.2
• /
• pp.41-47
• /
• 2008

This paper describes the results of model experiments in the laboratory, which were conducted to assess the behavior characteristics of geosynthetic reinforced soil walls according to different surcharge loads and reinforcement types. The model walls were built in the box having dimension, 100 cm tall, 140 cm long, and 100cm wide. Three types of geosynthetics, geonet, geogrid A and geogrid B, are used as the reinforcements. Decomposed granite soil (SM) was used as a backfill material. Seven model walls are constructed and tested. After the construction of the model wall, the LVDTs are installed to obtain the displacements of the wall face. As the results of the model tests, the maximum horizontal displacements of the model walls occurred due to uniform surcharge pressure were measured at the 0.7H from the bottom of the wall. The more the reinforcement strength increases, the more the wall displacements decrease, and also the reduction ratio of the wall displacement decrease with increasing the surcharge pressure.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.5
• /
• pp.109-116
• /
• 2004

The model tests are conducted to assess the behavior characteristics of geogrid reinforced soil walls according to different surcharge pressures and reinforcement spacings. The models are built in the box having dimension, 100cm tall, 140cm long, and 100cm wide. The reinforcement used is geogrid(tensile strength 2.26t/m). Decomposed ganite soil(SM) is used as a backfill material. The strain gauges and LVDTs are Installed to obtain the strain in the reinforcements and the displacements of the wall face. From the results, it can be concluded that the more the reinforcement tensile strength increases, the more the wall displacements and the geogrid strains decreases. The maximum wall displacements and geogrid strains of the model walls occur due to the uniform surcharge pressure at the 0.7H from the bottom of the wall. The horizontal displacements of the wall face nonlinearly increase with the increase of surcharge pressures, and this nonlinear behavior is significantly presented for larger surcharge due to the nonlinear tensile strength-strain relationship of the reinforcements.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.1
• /
• pp.94-104
• /
• 2004

The purpose of this study is to analyze various hydraulic characteristics using SMS (Surface Water Modeling System) RMA2 model. It is based on 2-D finite element method. River reaches (13.8km) from Gyeongan gauge station to the inlet of Paldang lake was selected. Finite element was made by RIMGIS Data, and the analysis of river-changes was operated by unsteady flow. The sediment concentration and bed change was simulated using SED2D model. This River's velocity was distributed that 0.05~3.85m/s and bed change was changed about 0.0003~0.0135m.

• Communications for Statistical Applications and Methods
• /
• v.16 no.1
• /
• pp.51-65
• /
• 2009

The purpose of a phase I clinical trial is to determine the maximum tolerated dose(MTD) of a new drug. This paper investigates the performance of standard method, continual reassessment method and accelerated titration designs in phase I clinical trials. Especially we study the precision and safety at the MTD of these methods. We utilize hyperbolic tangent function and power function to define dose-toxicity model. For each method, expected toxicity rate at MTD is computed and compared with target toxicity probability. We also suggest some modifications of these methods and show some improvements in performance.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.160-164
• /
• 2011

경기도 안산시 시화습지내에 위치한 하안 유도 시험장에 직선수로와 곡선수로를 시공하였다. 각각의 수로에 유도틀을 설치한 후 수리학적 특성을 분석하기 위해서 2차원 모형인 SMS를 이용하여 유량조건에 따른 유속 및 침식, 퇴적에 미치는 영향을 분석하고 예측하였다. SMS 모형 중 2차원 수리분석을 위한 RMA2 모형과 유사이송현황을 모의할 수 있는 SED2D 모형을 이용하여 하안유도 시험장에 적용하였으며 하안 유도 시험장은 크게 직선수로와 곡선수로로 구분하였다. 각각의 수로에 설치되는 유도틀은 ㄷ자형, ㄷㅂ자형, 직사각형, 마름모형이 있고, 총 10가지 경우로 하여 시험장 유도틀 형태별 2차원 수치모의를 분석하였다. 유속을 모의하기 위해 RMA2모형을 사용하였으며, 침식 및 퇴적을 모의하기 위해 SED2D모형을 사용하였다. 이러한 모의결과를 통해 실제 하천에서 유도틀 시공시 유량에 대한 하류 구간 대책을 수립하는 기초자료 활용하고자 한다.