• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.735-745
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• 2014

This paper presents PKES(PuKyung -Excel based Simulator) for WWTPs(wastewater treatment plants) by using MS Excel and VBA(Visual Basic for Application). PKES is a user-friendly simulator for the design and optimization of the whole plant including biological and physico-chemical processes for the wastewater and sludge treatment. PKES calculates the performance under steady or dynamic state and allows changing the mathematical model by the user. Mathematical model implemented in PKES is a improved integration model based on ASM2d and ADM1 for simulation of AS(activated sludge) and AD(anaerobic digestion). Gaseous components of $N_2$, $N_2O$, $CO_2$ and $CH_4$ are added for estimation of GHGs(greenhouse gases) emission. The simulation results for comparison between PKES and Aquasim(EAWAG) showed about the same effluent concentrations. As a result of verification using by measured data of BOD, TSS, TN and TP for 2 years of operation, calculated effluent concentrations were similar to measured effluent concentrations. The values of average RMSE(root mean square error) were 1.9, 0.8, 1.6 and 0.2 mg/L for BOD, TSS, TN and TP, respectively. Total GHGs emission of WWTP calculated by PKES was 138.5 ton-$CO_2$/day and GHGs emissions of $N_2O$, $CO_2$ and $CH_4$ were calculated at 21.7, 28.9 and 87.9 ton-$CO_2$/day, respectively. GHGs emission of activated sludge was 32.5 % and that of anaerobic digestion was 67.5 %.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1049-1056
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• 2017

In this paper, a microstrip-fed dual-band monopole antenna with two arc-shaped lines for WLAN(: Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a microstrip-fed structure, and composed of two arc-shaped lines and then designed in order to get dual band characteristics. We used the simulator, Ansoft's High Frequency Structure Simulator(: HFSS) and carried out simulation about parameters L2, L5, and with/without slit to get the optimized parameters. The proposed antenna is made of $13.0{\times}34.0{\times}1.0 mm^3$ and is fabricated on the permittivity 4.4 FR-4 substrate($12.0{\times}34.0{\times}1.0mm^3$). The experiment results are shown that the proposed antenna obtained the -10 dB impedance bandwidth 360 MHz (2.29~2.65 GHz) and 1,245 MHz (4.705~5.95 GHz) covering the WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required dual-band(2.4 GHz band/5.0 GHz band), respectively.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.454-460
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• 2007

In this paper, we implemented a ray-tracing simulator with a ray-launching technique and generated the propagation path of each ray in an multiple-wall indoor environment. In this simulator, we adopted two dimension ray-tracing techniques considering the reflection and penetration were dominant propagation factor in the indoor channel. From the result, we verified that this ray-tracing simulator shows the similar pattern and delay distribution with the experiment results of the previous research.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.459-465
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• 2007

In this paper, we implemented a ray-tracing simulator with a ray-launching technique and generated the propagation path of each ray in a multiple-wall indoor environment. In this simulator, we adopted two dimension ray-tracing techniques considering the reflection and penetration were dominant propagation factor in the indoor channel. From the result, we verified that this ray-tracing simulator shows the similar path pattern and delay distribution with the experiment results of the previous research. Especially, impulse responses of the ray were corresponding to reference result in non-line of sight of multiple-wall indoor environment. Furthermore, we confirmed that channel profiles having respectively different departure angle 1 degree to 7 degree were similar between them.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.4
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• pp.441-448
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• 2015

In this paper, a CPW-fed dual-band monopole antenna with two branch strips for WLAN(Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a CPW-feeding structure, and composed of two branch strips and then designed and tuned the length of two branch lines to obtained required frequencies bands. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and carried out simulation about parameters $L_5$, $L_8$, $W_3$, $W_5$, $W_9$. The proposed antenna is fabricated on the FR-4 substrate using the obtained parameters. The numerical and experiment results demonstrated that the proposed antenna obtained the -10 dB impedance bandwidth 1,095 MHz (1.57~2.665 GHz) for 2.4 GHz band and 1,680 MHz (4.99~6.67 GHz) for 5 GHz band satisfied requirement while simultaneously covering the WLAN bands. And characteristics of gain and radiation patterns are determined for WLAN operating bands.

• Korean Journal of Acupuncture
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• v.38 no.4
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• pp.267-274
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• 2021

Objectives : Acupoints education is important in that it can determine the clinical competency of Korean Medicine Doctors (KMDs). Accordingly, we aimed to develop a practical simulator for acupoints education, acupoints training, acupoints practice, and acupoints evaluation. Methods : Korean Medicine (KM) SMART Table can be divided into hardware, server and components, and is organically linked. We develop KM SMART Table that combines the hardware of a human-sized table with a UHD display capable of multi-touch in two cases and software that can teach acupoints. We make Augmented Reality (AR) contents linked with KM SMART Table contents and develop applications that can use contents using mobile devices. By developing an AR image tracking module to react with KM SMART Table, it enables acupoint learning according to the mobile device platform and human anatomy. Results : The current system is a prototype where some 3D technology has been implemented, but the AR function will be produced later. New learning using 3D and AR will be required during acupoints education and acupoints practice. It will be used a lot in OSCE (Objective Structured Clinical Examination) practices for strengthening the competency of KMDs, and it will be of great help not only in KM education as a unique simulator of KM, but also in the practice of acupuncture and chuna for musculoskeletal diseases. Conclusions : The KM SMART Table is a technology that combines 3D and AR to learn acupoints, and to conduct acupoints OSCE practice, and we suggest that it can be usefully used for educational evaluation.

• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.73-81
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• 2019

Various 3D contents are being developed using Unity 3D game engine. In this paper, the 3D content of horseback riding game, the first VR game in the country, is designed and developed. The existing riding simulator is investigated and compared to the VR riding game developed. We consider various games developed using Unity 3D game engine and serve previously developed tangible games. It is expected that development of VR riding games will prepare a new chapter in VR experience-type games. We propose the content development environment and scenario of VR riding game and present the main algorithms and main modules for real-time synchronization. The developed riding game contents are deployed to the riding system and are operated for commercial use in conjunction with the riding device. Through monitoring VR riding system, problems are derived and improvement measures are proposed. We offer a variety of additional development options to make the game more realistic in the future.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.9
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• pp.841-848
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• 2016

In this paper, a microstrip-fed dual-band monopole antenna with DGS(: Defected Ground System) for WLAN(: Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a microstrip-fed structure, and composed of two strip lines and DGS structure and then designed in order to get dual band characteristics. We used the simulator, Ansoft's High Frequency Structure Simulator(: HFSS) and carried out simulation about parameters W2, L10, W3, and DGS to get the optimized parameters. The proposed antenna is made of $21.0{\times}36.0{\times}1.6mm3$ and is fabricated on the permittivity 4.4 FR-4 substrate. The experiment results are shown that the proposed antenna obtained the -10 dB impedance bandwidth 700 MHz(2.10~2.80 GHz) and 1,780 MHz(5.02~6.80 GHz) covering the WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required dual-band(2.4GHz band/5.0GHz band), respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.10
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• pp.929-934
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• 2016

In this paper, we studied the design and fabrication of array antenna at around 1.8 GHz band. To improve of frequency properties of antenna, single feed microstrip patch antenna was simulated by HFSS(High Frequency Structure Simulator). A $1{\times}2$ array antenna of 1.8 GHz for LTE band was designed and fabricated by photolithography on an FR4 substrate (dielectric constant of 4.4 and thickness of 0.8 mm). The fabricated antenna was analyzed by network analyzer. The measured results agree well with the simulations, which confirmed the validity of this study. The fabricated $1{\times}2$ array antenna showed a center frequency, the minimum return loss and impedance were 1.82GHz, -30.5dB, and $49.6{\Omega}$ respectively.

• International Journal of Automotive Technology
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• v.5 no.4
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• pp.287-295
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• 2004

A performance simulator for the fuel cell hybrid electric vehicle (FCHEV) is developed to evaluate the potentials of hybridization for fuel cell electric vehicle. Dynamic models of FCHEV's electric powertrain components such as fuel cell stack, battery, traction motor, DC/DC converter, etc. are obtained by modular approach using MATLAB SIMULINK. In addition, a thermodynamic model of the fuel cell is introduced using bondgraph to investigate the temperature effect on the vehicle performance. It is found from the simulation results that the hybridization of fuel cell electric vehicle (FCEV) provides better hydrogen fuel economy especially in the city driving owing to the braking energy recuperation and relatively high efficiency operation of the fuel cell. It is also found from the thermodynamic simulation of the FCEV that the fuel economy and acceleration performance are affected by the temperature due to the relatively low efficiency and reduced output power of the fuel cell stack at low temperature.