• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.11
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• pp.33-40
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• 2005

This paper describes a design of FFT/IFFT Core(FFT256/2k), which is an essential block in terrestrial DMB modem. It has four operation modes including 256/512/1024/2048-point FFT/IFFT in order to support the Eureka-147 transmission modes. The hybrid architecture, which is composed of R2SDF and R2SDC structure, reduces memory by $62\%$ compared to R2SDC structure, and the SQNR performance is improved by TS_CBFP(Two Step Convergent Block Floating Point). Timing simulation results show that it can operate up to 50MHz(a)2.5-V, resulting that a 2048-point FFT/IFFT can be computed in 41-us. The FFT256/2k core designed in Verilog-HDL has about 68,400 gates and 58,130 RAM. The average power consumption estimated using switching activity is about 113-mW, and the total average SQNR of over 50-dB is achieved. The functionality of the core was fully verified by FPGA implementation.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.85-92
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• 2016

Mobile cloud computing (MCC) is not just extensions of cloud concepts into mobile environments, but the service technologies that all mobile devices including smartphone can use the desired services by using cloud technology without the constraints of time and space. Currently, a lot of works on mobile cloud computing have been actively researching, whereas user interfaces are not so much researched. The main features and contributions of this paper are as follows. First, develop UI considering UX that is different from conventional interfaces supported by SPICE. Second, combine two button interface into one button interface when keyboard is used in mobile cloud computing clients. Third, develop a mouse interface suitable for mobile cloud computing clients. Fourth, in mobile cloud computing client, solve a problem that the selection of button/files/folder has at the corner. Finally, in mobile cloud computing clients we change mouse scroll mapping functions from volume button to scroll interface in touch-screen. The results of performance evaluation shows that users can input easily with the increased and fixed mouse interface. Since shortcut keys instead of the complex button keys of keyboard are provided, the input with 3-6 steps is reduced into 1 step, which can simply support complex keys and mouse input for users.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.1
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• pp.107-116
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• 2009

Quantum-dot Cellular Automata (QCA) is one of the most promising next generation nanoelectronic devices which will inherit the throne of CMOS which is the domineering implementation technology for large scale low power digital systems. In late 1990s, the basic operations of the QCA cell were already demonstrated on a hardware implementation. Also, design tools and simulators were developed. Nevertheless, its design technology is not quite ready for ultra large scale designs. This paper proposes a new approach which enables the QCA designs to inherit the verification methodologies and tools of CMOS designs, as well. First, a set of disciplinary rules strictly restrict the cell arrangement not to deviate from the predefined structures but to guarantee the deterministic digital behaviors is proposed. After the gate and interconnect structures of. the QCA design are identified, the signal integrity requirements including the input path balancing of majority gates, and the prevention of the noise amplification are checked. And then the digital logic is extracted and stored in the OpenAccess common engineering database which provides a connection to a large pool of CMOS design verification tools. Towards validating the proposed approach, we designed a 2-bit adder, a bit-serial adder, and an ALU bit-slice. For each design, the digital logic is extracted, translated into the Verilog net list, and then simulated using a commercial software.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1163-1170
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• 2016

A hardware implementation of ultra-lightweight block cipher algorithm PRESENT which was specified as a standard for lightweight cryptography ISO/IEC 29192-2 is described. The PRESENT crypto-processor supports two key lengths of 80 and 128 bits, as well as four modes of operation including ECB, CBC, OFB, and CTR. The PRESENT crypto-processor has on-the-fly key scheduler with master key register, and it can process consecutive blocks of plaintext/ciphertext without reloading master key. In order to achieve a lightweight implementation, the key scheduler was optimized to share circuits for key lengths of 80 bits and 128 bits. The round block was designed with a data-path of 64 bits, so that one round transformation for encryption/decryption is processed in a clock cycle. The PRESENT crypto-processor was verified using Virtex5 FPGA device. The crypto-processor that was synthesized using a $0.18{\mu}m$ CMOS cell library has 8,100 gate equivalents(GE), and the estimated throughput is about 908 Mbps with a maximum operating clock frequency of 454 MHz.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.271-279
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• 2016

The objective of this study was to determine the effect of the moisture content and pellet mill type on the physical and chemical characteristics of Italian ryegrass (IRG) pellet. Moisture content of raw material significantly (p<0.05) affected IRG pellet formation. Moisture content at 25% was the best condition for IRG pellet formation in terms of shape, power load and temperature changes. The hardness of pellet was decreased when moisture content was increase. However, the hardness of pellet was not affected by pellet mill type. Moisture content at 30% dramatically (p<0.05) decreased the durability compared to moisture content at 25%. Dry matter content of IRG pellet was increased (p<0.05) after pelleting. Total count of microorganism was decreased in pellet due to pressure heat and moisture losses during the pelleting process. These results indicated that the proper moisture content of Italian ryegrass pelleting would be at 25%. In addition, Roll & flat die type would be more suitable than Ring die and Die & flat die type in IRG pelleting. Pelleting works would be beneficial for improving forage quality and long storage.

• Therapeutic Science for Rehabilitation
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• v.9 no.2
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• pp.87-98
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• 2020

Objective : The purpose of this study was to verify the effectiveness of home-visit occupational therapy in stroke patients. Methods : Two patients with stroke who applied for home-based occupational therapy services at a health center in Seoul were enrolled. The home-visit occupational therapy program evaluates the subject's daily living, task performance, cognitive, and emotional functions, sets occupational therapy goals and plans interventions based on a client-centered approach. Occupational therapy programs consisted of 12 sessions based on the client's major problems. Results : COPM scores improved in both cases, there was an improvement in COPM scores, and in Case 2 there were improvements in MBI and K-MMSE scores. There was also an improvement in KGDS scores in Case 1. Conclusion : Home-visit occupational therapy was found to be effective in improving daily activities, cognition, and mental function of stroke patients. During home and community integration, continuous and continuous rehabilitation services need to be activated from institutional rehabilitation to community-based rehabilitation. Active home-visit occupational therapy is needed to promote physical, cognitive, mental and social access in stroke patients discharged from hospitals.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.1
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• pp.51-64
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• 2020

The purpose of this study is to present a method for quantitative analysis of flooding at the flood plain in an ungauged area using satellite rainfall and global geographic data. For this, flooding of the Tumen/Namyang area in the Duman-gang(Riv.) was simulated and the flood conditions were quantitatively analyzed. The IMERG data, a rainfall data derived from satellite images, was used as rainfall data. The GRM model was applied to the watershed runoff simulation, and the G2D model was applied to the flooding simulation of the Tumen/Namyang area. Flood event caused by Typhoon Lionrock in August 2016 was applied. Recorded peak discharge of the Tumen/Namyang region was used to verify the runoff simulation results. To verify the result of the inundation simulation, the flood situation collected through field survey and satellite image data before and after the flood were used. The peak flow rates by the runoff simulation and flood record were 7,639㎥/s and 7,630㎥/s, respectively, with a relative error of about 0.1%. In the flood simulation, the results were similar to the flooding ranges identified in the survey data and satellite images. And the changes of flooding depth and flooding time in the flood plain in Tumen/Namyang area could also be assessed. The methods and results of this study will be useful for the quantitative assessment of floods in the ungauged areas.

• Journal of Life Science
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• v.30 no.3
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• pp.267-277
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• 2020

This study was conducted to assess the effect of highly concentrated onion intake on rodents. The experimental animals were divided two groups as follows; water administered group (CON) and Allium cepa administered group (ACE). The ACE group showed a slightly increases in the number of erythrocytes (RBC), hemoglobin (HGB), hematocrit (Hct) levels compared to the control group (p<0.05). Hemoglobin, monocyte, lymphocyte and neutrophil had no significant change (p>0.05) in ACE group and control group. The analysis of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels showed a significant decrease in ACE group compared to the control group (p<0.05). The blood glucose, total protein, HDL-cholesterol were slightly high in ACE group, while triglyceride, total cholesterol levels were lower in ACE group compared to the control group (p<0.05). The levels of cytokines (interluekin-1α (IL-1α), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), interferon-γ (INF-γ), interleukin-18 (IL-18), interleukin-2 (IL-2), granulocyte-macrophage colony-stimulating factor (GM-CSF)) involved in immunity and inflammation in liver tissue and blood have all been confirmed to be within normal range. These findings could be used as basic data to show that highly concentrated dietary onion extract is not toxic to hematological indicators and immune functions.

• Ecology and Resilient Infrastructure
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• v.4 no.1
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• pp.12-23
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• 2017

The Naeseong Stream is a meandering sand-bed stream flowing through mountains and has so long maintained its geomorphological uniqueness characterized by extensive braided bare bars. Recently, its long-lasting landscape has been changed due to encroachment of vegetation. In this study being a part of long-term monitoring research morphological changes of the 56.8 km long study reach of the Naeseong Stream, which occurred during the period of 2012 - 2016 were analyzed. Airborne LiDAR and terrestrial cross-section surveys were carried out. Hydrological and on-site investigation data were also collected. Among the main four sites, two bend reaches showed point bars enlarged, while along the other two straight reaches mid-channel bars were either newly formed or increased in area and height. At the highest deposition point of each bar, vertical changes which were caused by one or two times of sediment deposition amounted to 0.6 - 1.4 m. On the contrary channel bed degradation was not obvious. Overall morphological changes in the study reach were attributed to deposition of sediment which occurred during the flood in July 2016 on the bar surfaces vegetated during the precedent dry seasons. These kind of geomorphological processes are thought to be the same as those related to the existing mid-channel islands along the mid- and downstream reach of the Naeseong Stream.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1083-1091
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• 2017

This paper describes a design of cryptographic processor supporting 224-bit elliptic curves over prime field defined by NIST. Scalar point multiplication that is a core arithmetic function in elliptic curve cryptography(ECC) was implemented by adopting the modified Montgomery ladder algorithm. In order to eliminate division operations that have high computational complexity, projective coordinate was used to implement point addition and point doubling operations, which uses addition, subtraction, multiplication and squaring operations over GF(p). The final result of the scalar point multiplication is converted to affine coordinate and the inverse operation is implemented using Fermat's little theorem. The ECC processor was verified by FPGA implementation using Virtex5 device. The ECC processor synthesized using a 0.18 um CMOS cell library occupies 2.7-Kbit RAM and 27,739 gate equivalents (GEs), and the estimated maximum clock frequency is 71 MHz. One scalar point multiplication takes 1,326,985 clock cycles resulting in the computation time of 18.7 msec at the maximum clock frequency.