• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.353-360
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• 2020

This research aims at suggesting exposure condition that shows maintaining the value of the physical image quality factor by decreasing tube voltage and tube current from the standard exposure condition(80 kV, 7 mA) of a CBCT apparatus. To measure the value of the physical image quality factor, modular transfer function(MTF) was analyzed and dose-area product(DAP) was used for the measurement of exposure dose. CBCT images of a Sedentex IQ phantom were obtained under 15 exposure conditions of different combination of tube voltage(80, 78, 76 kV) and tube current(7, 6, 5, 4, 3 mA) and MTF 10 was calculated under each exposure conditions. There were no significant differences in MTF 10 under 80 kV-6 mA, 80 kV-5 mA exposure conditions in comparison with standard exposure condition. Based on the results of this research, 80 kV-5 mA condition are expected to be able to reduce exposure dose with maintaining the value of the physical image quality factor of the standard exposure condition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.9
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• pp.1332-1347
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• 1993

Existing instruments are composed independently according to their function and user constructed instrumentation system with those instruments. But in the late 1980s VXI bus enables to construct instrumentation system with various modular type instruments. For an VXI bus system with the word serial protocol, an increase of data size can degrade the system performance. In this paper shared memory protocol is proposed to overcome performance degradation. The shared memory protocol is analyzed using the GSPN and compared with that of the word serial protocol. It is shown that the shared memory protocol has a better performance than the word serial protocol. The VXI bus message based-system with the proposed shared memory protocol is constructed and experimented with signal generating device and FFT analyzing device. Up to 80 KHz input signal the result of FFT analysis is accurate and that result is agree with that of conventional FFT analyzer. In signal generating experiment from 100 KHz to 1.1 GHz sine wave is generated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1546-1554
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• 1999

In this paper, Dynamic Fault Tree algorithm(DFT algorithm) is presented. This algorithm provides a concise representation of dynamic fault tolerance system including fault recovery techniques with fault detection, mask and switching function. And this algorithm define FDEP, CSP, SEQ, PAG gate which captures the dynamic characteristics of system. It show that this algorithm solved the constraints to satisfy the dynamic characteristics of system which there are in Markov and also this is able to satisfy the dynamic characteristics of system which there are in Markov and also this is able to covered the disadvantage of Fault tree methods. To show the key advantage of this algorithm, a traditional method, that is, Markov and Fault Tree, applies to TMR and Dual-Duplex systems with the dynamic characteristic and a presented method applies to those. He results proved that the DFT algorithm for solving the problems of the system is more effective than the Markov and Fault tree analysis model..

• The Journal of the Convergence on Culture Technology
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• v.2 no.2
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• pp.29-35
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• 2016

The conventional educational robots, which are commonly industrial robots or toy robots, use text-based programming to teach the students. Therefore, students have difficulty in studying robotics due to the difficulties of text based language. The developed robot in this study have a camera, which have the color tracking function, and it has various sensors and actuators. It supports the open hardware and uses graphic language based programming. The developed educational robot is programmed by Scratch, which uses graphic modular language. We also present a curriculum, which is based upon the developed robot and Scratch. We applied the robot and curriculum to the primary school students. We obtained satisfactory results comparing it with the conventional robot education. Furthermore, the imagination and execution ability of students showed enhancement in learning robotics. Thus, this fact means the validity and effectiveness of the proposed approach.

• Journal of the Korean Society for information Management
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• v.28 no.1
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• pp.145-170
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• 2011

The purpose of this paper is to suggest a pilot model of knowledge organizing system which reflects the knowledge structure of research papers, using a case analysis on the "Korean Research Memory" of the National Research Foundation of Korea. In this paper, knowledge structure of the research papers in humanities and social science is described and the function of the "Korean Research Memory" for scholarly sense-making is analysed. In order to suggest the pilot model of the knowledge organizing system, the study also analysed the relation between indexed keyword and knowledge structure of research papers in the Korean Research Memory. As a result, this paper suggests 24 axioms and 11 inference rules for an ontology based on semantic relation of the knowledge structure.

• The KIPS Transactions:PartD
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• v.15D no.5
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• pp.629-646
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• 2008

Because most metricsin the literatures are described by a natural language, they can be interpreted in an ambigous manner. To cope with this problem, there are some researches to express based on Object Constraint Language(OCL). Because OCL has been proposed to describe structural constraintsfor Unified Modeling Language(UML) diagrams, it is difficult and awkward. In this paper, we propose Metric Description Language(MDL) which is a high level language to describe metrics. MDL supports a modular description of complex metrics, aggregation function, and automatic navigation between entities. Moreover, we develop MetriUs for describing metrics using MDL and supporting an automated computation for UML diagrams. In a case study, we have described a variety of existing metrics using MDL and found that MDL contributes to producing simpler expression of metrics than OCL.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1470-1476
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• 2020

This paper describes a design of a lightweight security system-on-chip (SoC) suitable for the implementation of security protocols for IoT and mobile devices. The security SoC using Cortex-M0 as a CPU integrates hardware crypto engines including an elliptic curve cryptography (ECC) core, a SHA3 hash core, an ARIA-AES block cipher core and a true random number generator (TRNG) core. The ECC core was designed to support twenty elliptic curves over both prime field and binary field defined in the SEC2, and was based on a word-based Montgomery multiplier in which the partial product generations/additions and modular reductions are processed in a sub-pipelining manner. The H/W-S/W co-operation for elliptic curve digital signature algorithm (EC-DSA) protocol was demonstrated by implementing the security SoC on a Cyclone-5 FPGA device. The security SoC, synthesized with a 65-nm CMOS cell library, occupies 193,312 gate equivalents (GEs) and 84 kbytes of RAM.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.2
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• pp.11-26
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• 2022

The Hallyu wave based on K-pop and K-culture has increased the global interest in Korean culture. Therefore, to satisfy consumer demand, there is an attempt to develop a variable fashion design using traditional Korean culture. Transformable fashion design causes changes in form and meaning according to various situations and needs and can induce active participation of consumers. Therefore, we intend to propose a transformable fashion design that is based on traditional Korean culture but appears in a new form and meets the needs of consumers of fashion design. Among Korean traditional culture, wrapping cloths, bojagi are practically used by ordinary people until now, and their shape and use change according to the user's needs. This study intends to derive expression characteristics by examining the expression tendencies of bojagi and to develop transformable fashion designs through the derived data. The purpose of this study is to make and propose transformable fashion designs in real life using the expression characteristics of Korean bojagi. As the method of this study, we first conducted a literature review. Through this, a case study of empirical production was conducted in parallel with the development and production of transformable fashion designs using bojagi. A total of three illustrations and six variable fashion designs were developed. Two of the six works are transformable fashion design that change through movement and expansion of the square shape, the prototype of the bojagi, and two works are modular, bringing changes in function through combination and separation. The work was produced as a multi-purpose transformable fashion design that can be used as clothes or a bag.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.133-144
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• 1995

After resection of intraarticular, periacetabulum(P2) and pubic rami(P23) and extraarticular, proximal femur(P2-H12) by Enneking classification, reconstruction is very difficult. We experienced three cases of saddle prostheses for reconstruction after P2, P23, and P2-H12 resection in pelvic malignancies. Case 1 was a high grade chondrosarcoma in 36 year-old-man and P2 resection was done. But he died of disease 19 months after operation. Case 2 was a malignant giant cell tumor in 32 year-old-woman. P23 resection was given and she is disease-free 32 months after operation. Case 3 was an osteosarcoma of 27-year-old-man and P2-H12 resection was performed and he is disease-free postoperative 12 months now. According to MSTS functional evaluatin system, all three patients showed no pain(5), intermediate function(2), emotinally satisfied(3), one cane or crutch supported(1), limited walking(3), and minor cosmetic gait(3). There was no significant complication and no dislocation except intermittent inguinal hernia in case 2. All patients started crutch walking 3 weeks after operation. Around 6 months postoperatively, the preserved iliac wing(P1 component) was hypertrophied enough to endure the full weight bearing. All could have squating and kneeling positions. In conclusion, saddle prosthesis would be a very useful method of reconstruction after P2, P23, and/or H1-2 resection to shorten the operation time and to reduce the infection rate without significant loss of function.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.1
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• pp.18-25
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• 1997

Prosthetic replacement is one of the most common methods of reconstruction after resection of malignant tumor around the knee. Gait analysis provides a relative objective data about the gait function of patients with prosthesis. The purpose of this study was to compare the gait pattern of the patients who underwent limb salvage surgery with prosthesis for distal femur and that of patients with prosthesis for proximal tibia. This study included ten patients (4 males, 6 females, mean age 22.7 years, range 14-36) who underwent a wide resection and Kotz hinged modular reconstruction prosthesis replacement and six normal adult(Control). The site of bone tumor was the distal femur (Group 1) in six patients and proximal tibia (Group 2) in 4 patients. The follow-up period ranged from 15 to 82 months (mean : 33 months). The evaluation consisted of clinical assessment, radiographic assessment, gait analysis using VICON 370 Motion Analysis System. The gait analysis included the linear parameters such as, walking velocity, cadence, step length, stride length, stance time, swing time, single support and double support time and the three-dimensional kinematics (joint rotation angle, velocity of joint rotation) of ankle, knee, hip and pelvis in sagittal, coronal and transverse plane. For the kinetic evaluation, the moment of force (unit: Nm/kg) and power (unit: Watt/kg) of ankle, knee and hip joint in sagittal, coronal and transverse plane. In the linear parameters, cadence, velocity, step time and single support were decreased in both group 1 and group 2 compared with control. Double support decreased in group 2 compared with control significantly(p<.05). In contrast to our hypothesis, there was no significant difference between group 1 and group 2. In Kinematics, we observed significant difference (p<.05) of decreased knee flexion in loading response (G2