• Journal of the Korean Magnetics Society
• /
• v.5 no.5
• /
• pp.376-379
• /
• 1995

Employing the muffin-tin-orbital theory combined with pseudo-potential concepts, we have evaluated hybridization matrix elements between R and T sites in $RT_{2}$ compounds. The matrix elements are calculated with two parameters, the interatomic distance between R and T atoms from the crystal structure data, and the expectation values of the radial distances for the radial wave functions of the ground state charge densities, which are obtained from the linearized muffin-tin orbital band method within the local density approximation. It is found that the R 4f/T 3d hybridization matrix elements decrease with an increasing atomic number from R=Ce to Gd, and that they are smaller in $RNi_{2}$ than in $RCo_{2}$, which are consistent with trends observed in recent photoemission spectroscopy experiments. It is also found that the magnitudes of the hybridization matrix elements in $RFe_{2}$ are comparable to those in $RNi_{2}$.

• Bulletin of the Korean Chemical Society
• /
• v.7 no.5
• /
• pp.334-337
• /
• 1986

The preparation of the metal-metal bonded complex $Cp_2ZrClFeCp(CO)_2$ has been achieved by the reaction of $Cp_2ZrCl_2$ and strong nucleophile $NaFeCp(CO)_2$. The more soluble metal-metal bonded complexes $Cp_2ZrRFeCp(CO)_2(R=CH_3,\;n-C_8H_{17}$) have also been prepared through the reaction of Cp$_{2}$ZrRCl and NaCpFe(CO)$_{2}$. The complexes were characterized by IR, Raman, $^{1}$H NMR and Mass spectra. The complete absorption (100-3800 cm$^{-1}$) spectra for the three metal-metal bonded molecules are reported and the bands of each vibration were assigned.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.303-314
• /
• 2010

This study, as basic research which was intended to develope the surface reinforcement method using reinforcement material which is applicable to very soft ground in Korea, was aimed at proposing the design parameter for the surface ground improvement method. To that end, a wide width tensile test using geotextile, geogrid and steel bar (substitute for bamboo) and 49 kinds of the laboratory model tests were conducted. And the result the study suggested $\beta_s$, the stiffness coefficient to evaluate the stiffness effect of reinforcement materials. Then, it was also found that the stiffness coefficient, $\beta_s$ as the testing constant would be appropriate as high as 1.0, 1.1 and 1.5 for geotextile, geogrid and steel bar, respectively. And It was evaluated that the stiffness effect affecting reinforcement improvement effect would be reduced as the thickness of embeded depth increases and that RFe, the stiffness effect reduction coefficient would have positive correlation with H/B. Finally, it was confirmed that the bearing capacity gained from the method to calculate bearing capacity, which was suggested in the study, would almost correctly estimate the capacity, demonstrating the appropriateness of the proposed bearing capacity calculation method.

• Proceedings of the KIEE Conference
• /
• 2006.07d
• /
• pp.2140-2141
• /
• 2006

RFID 기술은 모든 사물에 태그를 부착하여 전파를 이용하여 사물에 대한 정보를 자동으로 인식하고 이를 실시간으로 네트워크에 연결하여 정보를 관리하는 기술이다. RFE에 기반한 어플리케이션은 사용자의 요구에 의한 응용프로그램과 달리 태그의 인식이 프로그램 실행을 발생하게 하므로 실시간이벤트 처리, 실시간 이벤트 모니터링을 처리가 가장 중요하다. 하지만 리더로부터 인식된 태그 데이터가 아무런 정제 작업 없이 직접 응용어플리케이션에 전달되게 된다면 불필요한 연산을 수행하게 되어 성능이 저하되는 요인이 된다. RFID 미들웨어의 주된 역활은 리더기와 응용시스템 사이에 데이터들을 전송하는데 있다. 따라서 태그 데이터 처리 기능을 통해 응용 시스템에 신뢰성 있는 정보제공은 미들웨어에서 중요한 기능을 수행하게 된다. 본 논문에서는 응용시스템에 신뢰성 있는 데이터 전송에 필수 기능인 불필요한 이벤트를 제거하는 필터링 기능을 위한 프레임워크 설계, 구현하였다

• Smart Structures and Systems
• /
• v.15 no.6
• /
• pp.1601-1623
• /
• 2015

Electroactive polymers have attracted considerable attention in recent years due to their sensing and actuating properties which make them a material of choice for a wide range of applications including sensors, biomimetic robots, and biomedical micro devices. This paper presents an effective modeling strategy for nonlinear large deformation (small strains and moderate rotations) dynamic analysis of polymer actuators. Considering that the complicated electro-chemo-mechanical dynamics of these actuators is a drawback for their application in functional devices, establishing a mathematical model which can effectively predict the actuator's dynamic behavior can be of paramount importance. To effectively predict the actuator's dynamic behavior, a comprehensive mathematical model is proposed correlating the input voltage and the output bending displacement of polymer actuators. The proposed model, which is based on the rigid finite element (RFE) method, consists of two parts, namely electrical and mechanical models. The former is comprised of a ladder network of discrete resistive-capacitive components similar to the network used to model transmission lines, while the latter describes the actuator as a system of rigid links connected by spring-damping elements (sdes). Both electrical and mechanical components are validated through experimental results.

• Acta Via Serica
• /
• v.2 no.2
• /
• pp.133-162
• /
• 2017

The Bering Strait crossing would link the entirety of Eurasia to the entirety of the Americas, and it can be seen as a natural extension of the historical Silk Road. There are some immense geopolitical benefits to such a project. It would bring about a profound and lasting change to the global economic and political outlook. The most valued function of the Bering Strait crossing and the extension of the associated railroad network would be to release the massive natural resources trapped underneath the tundra and permafrost for the benefit of Russia and the world. Moreover, the railroad project(s) would also build development corridors in those underdeveloped parts of the Russian Federation. The development of the resources and their rapid transportation to the global markets would contribute not only to the overall development of the region but also would be valuable for the resource-poor countries of Northeast Asia such as Japan, Korea, and China (relative to its economic size). This paper will explore the possible impact(s) of the Bering Strait crossing as a formidable infrastructure project for the economic development of the Russian Far East (RFE) from the Russian perspective under the frame of geopolitics. Furthermore, it will equally scrutinize the implications for the adjacent countries in the region.

• Journal of the Korean association of regional geographers
• /
• v.14 no.2
• /
• pp.141-158
• /
• 2008

The goal of this paper is to analyze Korean migration to the Russian Far East(RFE) from the perspective of transnationalism. The analysis suggests that the Korean migrants could have constructed their transnational identities using the following practices: religious ritual, language uses, collective remittances, ethnic businesses, immigrant newspapers, and immigrant associations. In particular, the Korean migrants could have retained transnational interconnection between the places of origin and destination even without the process of globalization, which is regarded as an inevitable incentive to transnationalism in the literature. The Korean case indicates that the contextual changes in the sending and receiving countries, for instance, the establishment of a Japanese protectorate over Korea and the Russian Revolution, significantly facilitated the formation of transnational relationships among the Korean immigrants.

• Journal of Korea Multimedia Society
• /
• v.24 no.5
• /
• pp.667-675
• /
• 2021

The treatments for symptoms of Alzheimer's disease are being provided and for the early diagnosis several researches are undergoing. In this regard, by using T1-weighted images several classification techniques had been proposed to distinguish among AD, MCI, and Healthy Control (HC) patients. In this paper, we also used some traditional Machine Learning (ML) approaches in order to diagnose the AD. This paper consists of an improvised feature selection method which is used to reduce the model complexity which accounted an issue while utilizing the ML approaches. In our presented work, combination of subcortical and cortical features of 308 subjects of ADNI dataset has been used to diagnose AD using structural magnetic resonance (sMRI) images. Three classification experiments were performed: binary classification. i.e., AD vs eMCI, AD vs lMCI, and AD vs HC. Proposed Feature Selection method consist of a combination of Principal Component Analysis and Recursive Feature Elimination method that has been used to reduce the dimension size and selection of best features simultaneously. Experiment on the dataset demonstrated that SVM is best suited for the AD vs lMCI, AD vs HC, and AD vs eMCI classification with the accuracy of 95.83%, 97.83%, and 97.87% respectively.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.136-136
• /
• 2022

This study investigates the possibility of coupling empirical mode decomposition (EMD) for runoff prediction from machine learning (ML) models. Here, support vector regression (SVR) and convolutional neural network (CNN) were considered for ML algorithms. Precipitation (P), minimum temperature (Tmin), maximum temperature (Tmax) and their intrinsic mode functions (IMF) values were used for input variables at a monthly scale from Jan. 1973 to Dec. 2020 in the Grand river basin, Canada. The support vector machine-recursive feature elimination (SVM-RFE) technique was applied for finding the best combination of predictors among input variables. The results show that the proposed method outperformed the individual performance of SVR and CNN during the training and testing periods in the study area. According to the correlation coefficient (R), the EMD-SVR model outperformed the EMD-CNN model in both training and testing even though the CNN indicated a better performance than the SVR before using IMF values. The EMD-SVR model showed higher improvement in R value (38.7%) than that from the EMD-CNN model (7.1%). It should be noted that the coupled models of EMD-SVR and EMD-CNN represented much higher accuracy in runoff prediction with respect to the considered evaluation indicators, including root mean square error (RMSE) and R values.

• The Korea Journal of Herbology
• /
• v.25 no.4
• /
• pp.1-6
• /
• 2010

Objective : The purpose of this study is to compare anti-thrombotic activities of 4 Rhubarb species. Methods : Rhubarb has been used as medical and edible resources worldwide for the therapy of cancer, constipation and inflammation, etc. To compare the anti-thrombotic activities among the species within rhubarb, we investigated and compared the inhibitory properties of water extracts from R. palmatum(RPE), R. officinale(ROE), R. nobile(RNE), and R. franzenbachii (RFE) on the fibrinolysis, blood coagulation and platelet aggregation. APTT and PT, blood coagulation time, were measured by apparatus of auto blood coagulation analysis that called ACL-7000. The measurement of fibrinolysis was measured and compares with the width of clear zone from melted fibrin plate. The platelet aggregation was measured and compared with inhibition rate of aggregation. Results : We found out the best species from rhubarb showing the significant fibrinolytic, anti-coagulant and anti-platelet aggregation activity. Our results show that Rheum nobile (RNE) has the most effective anti-thrombotic activity among 4 tested rhubarb. Conclusions : This study, therefore, RNE will be able to be used the development of drug which is thrombosis treatment.