• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.4
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• pp.90-99
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• 2017

The service structure of the Mobius IoT platform, which has been developed on the basis of the oneM2M standard, connects servers and gateways directly to exchange data using HTTP or MQTT. Such structure may cause problems not to operate IoT services safely. In this paper, we propose an effective structure to manage sessions between gateways (or devices) and server using SIP safely and stably. In addition, we provide the way to implement the proposed method on Mobius IoT platform. To verify the operation of the proposed method, we actually implement the proposed method on Mobius IoT platform, and construct a testbed for a typical IoT application service environment with SIP servers. The results of the experiment show that the proposed method works normally, and it can contribute to the stable operation of IoT services.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.169-173
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• 2008

Stirling engine is a promising heat engine with a high efficiency, muti-fuel capability, low emission, quiet operation, very low maintenance and long life. As one of the promising applications, solar power system based on the Stirling dish, providing net solar-to-electric conversion efficiencies reaching 30%, can operate as stand-alone units in remote locations or can be linked together in groups to provide utility-scale power. This paper introduced a new Scroll-type Stirling engine, being developed for solar power, superior to conventional Stirling engines. The Scroll-type Stirling engine is characterized as traits of continuous and wholly separated compression and expansion; one-way flow system; direct cooling and heating the fluid in the working spaces through the extensive inner surfaces of scroll wraps. All theses traits contribute to achieving thermodynamic cycle closer to the ideal Stirling cycle (exactly speaking, Ericsson cycle).

• Journal of the military operations research society of Korea
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• v.1 no.1
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• pp.131-135
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• 1975

One of the pending issues of the Ministry of Defense is the efficient management of space parts for the weapon systems. It has been known that more than 000 million dollars are needed for spare parts for the weapon systems annually. Though the problem demands a serious consideration, there has not been any systematic study on the problem as far as the author knows. One way to approach the problem is through an investigation of the system reliability under constraints. A measure of how well a system performs or meets its design objectives is provided by the concept of system reliability. If successful operation is desired for a specified period of time, reliability is defined as the probability that the system will perform satisfactorily for the required time period. This interpretation of reliability is normally applied to devices which are subject to random failures such as electrical or mechanical systems. It has been found necessary to express system reliability in terms of the reliability of the components or subsystems which comprise the system. The major subsystems of an aircraft, for example, include the electronics, powerplant, airframe and armament subsystems. Therefore, the optimal spare part kit can be found by maximizing the system reliability subject to cost or other constraints.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.226-232
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• 1995

Survival rate of osteosarcoma has been improved recently due to the neoadjuvant and adjuvant chemotherapy. Limb-salvaging operation(LSO) has replaced the amputation technique without' lowering the survival rate. And there occurred a lot of patients who are suffering from the high cost of artificial implants and forced to choose amputation due to economic problem. In LSO, usually relatively high cost artifical implant is needed. When a patient and not afford such an expensive implant he had to choose an inexpensive way, amputation. Authors tried bone lengthening by adopting Ilizarov technique after wide resection of tumor in two patients. Bone transportation was successful in one patient and less successful in the other. One case in CDF(continuosly disease free since the surgical procedure) state at follow-up 3 year 4 months after knee joint fusion. And the other was given lobectomy for lung metastasis at postop. 1 year and 9 months, and given osteosynthesis for infected nonunion at the docking site. Bone transportation was thought to be a good method for the bony coverage of dead space caused by wide resection. Bone transportation technique was economical as well as biological We present two osteosarcoma patient who treated with Ilizarov bone transportation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1368-1375
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• 2013

The Smart Grid, which can monitor or diagnose the power grid in real time to operate efficiently, has been pushed ahead systematically as one of alternatives to solve these issues by combining the advanced Information Communication Technology and the electrical network. Hence, the electric company which introduces smart grid technology can read remotely the electrical meter readings by means of two-way communication between the meter and the central system. This enabled the customer and the utility to take part in reasonable electrical energy utilization. AMI became one of the core foundations in realizing the Smart Grid. It is hard to test the entire process of AMI system before the full deployment because it covers the broad objects from the customer to the utility operation system and requires mass data handling and management. Therefore, we design an efficient AMI network model and a simulator for performance evaluation required to simulate the network model similar to the real environment. This tool supports to evaluate the efficiency of the AMI network equipments and deployment. Additionally, it estimates the appropriate number of deployments and the proper capabilities.

• Geomechanics and Engineering
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• v.20 no.4
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• pp.359-370
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• 2020

Prestressed ground anchors are important structural elements in geotechnical engineering. Despite their widespread usage, the design process is often significantly simplified. One of the major drawbacks of commonly used design methods is the assumption that skin friction is mobilized uniformly along an anchor's fixed length, one consequence of which is that a progressive failure phenomenon is neglected. The following paper introduces an alternative design approach - a computer algorithm employing the load-transfer method. The method is modified for the analysis of anchors and combined with a procedure for the derivation of load-transfer functions based on commonly available laboratory tests. The load-transfer function is divided into a pre-failure (hardening) and a post-failure (softening) segment. In this way, an aspect of non-linear stress-strain soil behavior is incorporated into the algorithm. The influence of post-grouting in terms of radial stress update, diameter enlargement, and grout consolidation is included. The axial stiffness of the anchor body is not held constant. Instead, it gradually decreases as a direct consequence of tensile cracks spreading in the grout material. An analysis of the program's operation is performed via a series of parametric studies in which the influence of governing parameters is investigated. Finally, two case studies concerning three investigation anchor load tests are presented.

• Archives of Craniofacial Surgery
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• v.21 no.1
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• pp.35-40
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• 2020

Background: Extensive eyelid defects are extremely challenging to reconstruct. Although numerous procedures for reconstructing periorbital defects have been proposed, no method is universally used. However, the Tenzel flap is the most commonly used technique to reconstruct eyelid defects affecting one-third to two-thirds of the eyelid. Methods: Recognizing the usefulness of the Tenzel method, we adapted it to reconstruct larger defects around the eyes. Seven patients underwent reconstruction with a modified Tenzel flap with an extended concept after wide excision of a malignant skin lesion. The main difference from the conventional method is that the modified Tenzel flap includes the medial portion of the lower lid defect. The design of a modified Tenzel flap begins as a semicircle at the lateral canthal area, in the same way as a classical Tenzel flap, and extends medially along the subciliary line to cover the defect on the medial lower eyelid. The follow-up time ranged from 3 to 28 months. Results: All flaps survived and healed well, with minimal scarring and natural palpebral outlines. Conclusion: Compared to traditional procedures, the modified Tenzel flap has several advantages, including a one-stage operation, a less noticeable scar, and effective prevention of complications such as lower eyelid ectropion.

• Journal of IKEEE
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• v.16 no.4
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• pp.382-388
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• 2012

An H.264/AVC fast motion estimation methodology is presented in this paper. Advanced SIMD based NEON which is one of the parallel processing methods is supported under the ARM Cortex-A9 dual-core platform. NEON is applied to a full search technique with one of the various motion estimation methods and SAD operation count of each macroblock is reduced to 1/4. Pixel values of the corresponding macroblock are assigned to eight 16-bit NEON registers and Intrinsic function in NEON architecture carried out 128 bits arithmetic operations at the same time. In this way, the exact motion vector with the minimum SAD value among the calculated SAD values can be designated. Experimental results show that performance gets improved 30% above average in accordance with the size of image and macroblock.

• Korean Journal of Community Nutrition
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• v.15 no.2
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• pp.266-274
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• 2010

The purposes of this study were to evaluate on the importance about the possible remedies for improvement of sanitation management by foodservice manager and to compare dietitians' opinion and that of administrators about theirs. A questionnaire survey was performed by 282 dietitians and 56 administrators, who were involved at foodservice facilities in Daegu and Gyeongbuk from March 7 to March 9 in 2007. According to the results of the importance evaluation analysis about the remedies for improvement of sanitation management, there were significant differences between dietitians and administrators in the means of 6 items such as "remodeling of hygiene equipment and facilities", "improvement of dietitians' food safety knowledge", "self-operated management of foodservice operation", "enforcement of cooperation between the CEO or administrators and dietitians", "development of food safety education program for foodservice workers", "increasing of foodservice operating budget". In all of them, the dietitians' evaluation scores were significantly higher than that of administrators. In addition, four factors were extracted by exploratory factor analysis. According to the results of one-way ANOVA, operating, education, and policy support sector showed that significant differences across type of foodservice, frequency of meals served, number of meals served per day, dietitians' education level and career. On the other hand, supervision sector showed that significant differences across number of meals served per day and dietitians' employment type. In conclusion, in order to increase the quality of sanitation in the foodservice operation, we should increase sanitation performance and enforce the food-safety education for foodservice workers. In addition, government should increase the policy support.

• Journal of the Korean Society for information Management
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• v.22 no.3 s.57
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• pp.201-211
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• 2005

The archive management system for the National Assembly is divided into two ways and propelled by each of them : one is providing the service for the recording purpose by the legislation data processing office and the other is the archiving service by the National Assembly Archives. In this context, a clear analysis is much required for the organization and operation of the archive management system. Also, with the legislation research bureau scheduled to be organized newly, the data processing policy for the National Assembly is being largely modified as the operation plan for the joint computerization center of the National Assembly came out. In relation to the data processing of the National Assembly, the Assembly has requested the research outsourcing to the Korean Research Institute of Electronic Government and had the four possible operation plan of the computerization center as a result. On the basis of four alternatives proposed by the Korean Research Institute of Electronic Government, the Assembly has sought out the desirable way for the archive system of the Assembly. The status of the National Assembly Archives is taken into consideration in finding out the solution for improving the data management system of the National Assembly.