• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1718-1733
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• 2023

The virtual Frisch-grid method for room-temperature radiation detectors has been widely used because of its simplicity and high performance. Recently, side electrodes were separately attached to each surface of the detectors instead of covering the entire detector surface with a single electrode. The side-electrode structure enables the measurement of the three-dimensional (3D) gamma-ray interaction in the detector. The positional information of the interaction can then be utilized to precisely calibrate the response of the detector for gamma-ray spectroscopy and imaging. In this study, we developed a 3D position-sensitive 5 × 5 × 12 mm³ cadmium-zinc-telluride (CZT) detector and applied a flattening method to correct detector responses. Collimated gamma-rays incident on the surface of the detector were scanned to evaluate the positional accuracy of the detection system. Positional distributions of the radiation interactions with the detector were imaged for quantitative and qualitative evaluation. The energy spectra of various radioisotopes were measured and improved by the detector response calibration according to the calculated positional information. The energy spectra ranged from 59.5 keV (emitted by ²⁴¹Am) to 1332 keV (emitted by ⁶⁰Co). The best energy resolution was 1.06% at 662 keV when the CZT detector was voxelized to 20 × 20 × 10.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.324-332
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• 2007

In this paper, we developed remote control devices that can be controlled passive component e.g. resistor, inductor, capacitor that is a basic element in the electric circuit. We embodied a remote laboratory for basic circuit theory which learners can experiment controlling element value to remote through the internet. It was seen that is useful applying passive component developing to a remote laboratory. Because developed passive components can response in an experiment altering several element values to remote, they will be used very usefully in a remote experiment that equip various experiment theme. Therefor the proposed laboratory will be solved problems of virtual laboratory which students do not handle instruments in engineering experiment. With our proposed system, students can experiment any time, anywhere.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.282-288
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• 2014

Three-dimensional multimedia industry such as 3D TV, movie and broadcast has been developed vividly. For generating 3D contents with high quality, virtual auditory display, so called VAD, is being researched to offer more realistic experience to listeners. When people render VAD using headphones or two speakers, head-related transfer function(HRTF) plays a key role. The best solution is measuring all individuals' HRTFs, but it is hard to measure all listeners' HRTFs. To overcome this difficulty, many research groups have tried to construct their own measurement system and to build HRTF databases. However, some of them have not enough subjects or spatial resolution and they are mainly focused on Caucasian. There exists difference between Korean and Caucasian in a view of physical features. In other words, if Koreans hear three-dimensional sound rendered by HRTF database based on Caucasian, performance might be hindered. To verify this possibility and remedy the drawbacks, construction of new HRTF database aimed at Korean is needed. Therefore, our laboratory built HRTF measurement system which can measure HRTF of three-dimensional space with dense spatial resolution. With this system, 55 Korean males and 45 females' HRTFs were measured and Korean HRTF database was built based on these data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.671-686
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• 2020

Due to the long training time and high training cost of traditional surgical training methods, the emerging virtual surgical training method has gradually replaced it as the mainstream. However, the virtual surgical system suffers from poor authenticity and high computational cost problems. For overcoming the deficiency of these problems, we propose an optimized model for the local compression deformation of soft tissue. This model uses a simulated annealing algorithm to optimize the parameters of the soft tissue model to improve the authenticity of the simulation. Meanwhile, although the soft tissue deformation is divided into local deformation region and non-deformation region, our proposed model only needs to calculate and update the deformation region, which can improve the simulation real-time performance. Besides, we define a compensation strategy for the "superelastic" effect which often occurs with the mass-spring model. To verify the validity of the model, we carry out a compression simulation experiment of abdomen and human foot and compare it with other models. The experimental results indicate the proposed model is realistic and effective in soft tissue compression simulation, and it outperforms other models in accuracy and real-time performance.

• Journal of Internet Computing and Services
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• v.16 no.4
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• pp.61-70
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• 2015

This paper presents a web-based Java applet for understanding the concepts in digital logic circuits and student satisfaction survey was carried out in order to show its educational validity. Through our educational Java applet, the learners will be capable of learning the concepts and principles related to digital logic circuit experiments and how to operate virtual experimental equipments and virtual bread board. The proposed educational Java applet is composed of five important components: Principle Classroom to explain the concepts and principles for digital logic circuit operations, Simulation Classroom to provide a web-based simulator to the learners, Virtual Experiment Classroom to provide interactive Java applet about the syllabus of off-line laboratory class, Assessment Classroom, and Management System. With the aid of the Management System every classroom is organically tied together collaborating to achieve maximum learning efficiency. Finally, we have obtained several affirmative effects such as high learning standard, reducing the total experimental hours and the damage rate for experimental equipments.

• Annual Conference of KIPS
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• 2013.11a
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• pp.1121-1124
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• 2013

프로그램 실행 시 동화(텍스트)를 읽을 수 있게 하는 입력 파일을 받을 수 있게 만든다. 이렇게 받은 텍스트를 프로그램이 읽어 들여 알고리즘으로 대입한다. 알고리즘은 읽은 텍스트 중에 중요 단어를 뽑아내어 DB에 이에 알맞은 삽화를 요청하게 된다. 요청을 받은 데이터베이스는 다시 프로그램에 이미지를 보내주고, 프로그램은 이 삽화를 그 텍스트에 출력시키게 된다. 이 과정이 한 페이지를 만드는 과정이며, 원하지 않는 페이지는 건너 뛸 수 있게 한다. 이러한 작업을 반복하여 새로운 책 한권이 완성이 된다.

• Smart Media Journal
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• v.11 no.6
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• pp.51-63
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• 2022

Metaverse provides a simulated environment where a large number of users can participate in various activities. In order for Metaverse to be sustainable, it is necessary to study ethics that can be applied to a Metaverse service platform. In this paper, Metaverse ethics and the rules for applying to the platform are explored. And, in order to judge the ethicality of avatar actions in social Metaverse, the identity, interaction, and relationship of an avatar are investigated. Then, an action-based audit approach to avatar interactions (e.g., dialogues, gestures, facial expressions) is introduced in two cases that an avatar enters a digital world and that an avatar requests the auditing to subjects, e.g., avatars controlled by human users, artificial intelligence (AI) avatars (e.g., as conversational bots), and virtual objects. Pseudocodes for performing the two cases in a system are presented and they are examined based on the description of the avatars' actions.

• Computers and Concrete
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• v.34 no.4
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• pp.447-476
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• 2024

The current research proposes an innovative finite element model established within the context of higher-order beam theory to examine the bending and buckling behaviors of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beams resting on Winkler-Pasternak elastic foundations. This two-node beam element includes four degrees of freedom per node and achieves inter-element continuity with both C¹ and C⁰ continuities for kinematic variables. The isoparametric coordinate system is implemented to generate the elementary stiffness and geometric matrices as a way to enhance the existing model formulation. The weak variational equilibrium equations are derived from the principle of virtual work. The mechanical properties of FG-CNTRC beams are considered to vary gradually and smoothly over the beam thickness. The current investigation highlights the influence of porosity dispersions through the beam cross-section, which is frequently omitted in previous studies. For this reason, this analysis offers an enhanced comprehension of the mechanical behavior of FG-CNTRC beams under various boundary conditions. Through the comparison of the current results with those published previously, the proposed finite element model demonstrates a high rate of efficiency and accuracy. The estimated results not only refine the precision in the mechanical analysis of FG-CNTRC beams but also offer a comprehensive conceptual model for analyzing the performance of porous composite structures. Moreover, the current results are crucial in various sectors that depend on structural integrity in specific environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.876-879
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• 2012

In this paper we studied the radiation detection technology which described the radiation level distribution in high radiation area with remotely and safely. The designed radiation mapping system was composed of radiation nodes and radiation station. The radiation nodes could sense the radiation dose values with pMOSFET radiation sensors and transmit them to the radiation station. At the radiation station the received radiation values were merged with a geometric information and visualized at the virtual graphic location. For the functional verification of the above system, we attached the radiation nodes to each corner in our laboratory, executed the mapping tests, and confirmed the designed functions finally.

• Journal of Biosystems Engineering
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• v.29 no.3
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• pp.243-250
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• 2004

본 연구에서는 국내 미곡도정공장의 도정기계 작동상태와 가공된 발 품질의 원격감시를 위해서 인터넷기반 감시시스템을 개발하고자 하였다. 인터넷 감시시스템은 Laboratory Virtual Instrument Engineering Workbench(Lab VIEW)를 이용하여 개발되었으며 Hypertext Transfer Protocol(HTTP)을 제공할 수 있는 중앙서버, 현장제어용 Programmable logic controller (PLC) 및 각종 센서 등으로 구성되었다. 비상상태를 대비하기 위하여 도정기계를 원격으로 제어(ON/OFF)할 수 있도록 제어알고리즘을 설계하였다. 개발된 인터넷기반 감시시스템은 미곡 도정공장에 설치한 모든 도정기계의 작동상태, 백미 탱크내의 백미 무게와 백미의 온도 및 평형상대습도를 실시간으로 감시할 수 있었으며, 원격으로 측정한 백미탱크내의 평형온도 및 평형상대습도를 이용하여 백미의 함수율도 예측할 수 있었다. 거리 및 인터넷속도에 의해 발생된 시간지연의 측정과 원격으로 수집된 자료의 검증을 통해 인터넷 감시시스템의 성능을 평가하였다. 인터넷상의 시간지연(서울-광주간)은 약 1.2$\pm$0.2s 이었다.