• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.162-169
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• 2011

The flight control system utilize RSS(Relaxed Static Stability) criteria in both longitudinal axes to achieve performance enhancements and improve stability. The aircraft using digital flight-by-wire flight control system receives aircraft flight conditions such as pitch, roll and yaw rate, normal acceleration from RSA(Rate Sensor Assembly) and ASA(Acceleration Sensor Assembly). These sensors has permissible measurement error related to system safety of an aircraft but, unexpected flight motions are happened by sensing errors such as offset, noise and etc. The unexpected pitch down tendency occurred by ASA sensor bias in 1g level flight with pilot hands-off. This paper addresses the design and verification of flight control law to improve of pitch down or up tendency caused by ASA sensor bias. The result of analysis and flight test reveals that pitch down tendency can be improved by pitch attitude feedback system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.183-186
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• 2006

It is studied the implementation possibility of some encryption algorithms which meet the performance requirements in the smart card used in the TETRA system End-to-End Encryption. It is measured the operation time of the algorithm in the smart card which has 32 bit smart card controller made by Samsung Electronics. The algorithms used in the performance comparison are AES, ARIA, 3DES, SEED, IDEA which are the domestic or international standards. The input and output time of the smart card are measured using the smart card protocol analyzer. The pure algorithm operation time is calculated by the repeated algorithm operations. This measurement results can be used as the criteria for the selection of algorithm which will be used in the TETRA End-to-End encryption system. The algorithm which has better performance can be used for the implementation of additional functions in the smart lard, because of the enough time margin.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.131-137
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• 2010

In this paper, overseas criteria and research results were reviewed to develop a rational criterion proper to domestic airport runways on measurement of friction coefficient and removal of rubber deposit. The friction coefficients of the runways of the Incheon International Airport were measured by the ASFT(Airport Surface Friction Tester) from August 2007 to July 2009 and the data at intensively landed points were analyzed. Variation of the friction coefficient due to accumulation and removal of tire rubber was analyzed and seasonal influence on the variation were investigated by pavement types. The friction coefficient steadily decreased over a long term despite periodical removal of the rubber deposits. The variation of the friction coefficient in summer was larger than other seasons and asphalt pavement was more sensitive to the seasonal influence than concrete pavement. The friction coefficient of the asphalt pavement with macro texture was even larger than that of early age concrete pavement with micro texture. The variation of the friction coefficient of the asphalt pavement due to the deposit and removal of the tire rubber was also larger than that of the concrete pavement.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.585-589
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• 2011

Purpose: Microcirculation of diabetic patients is commonly comporomised, regardless of the condition of the macrocirculation. Therefore, direct tissue oxygenation measurement is recommended in determining tissue viability and predicting wound healing potential. This study was designed to determine cut-off value of the tissue oxygenation in predicting wound healing in diabetic foot patients. Methods: This study included 41 feet of 41 diabetic foot patients who were treated in the Diabetic Wound Center of author's institution between January and June, 2009. Main inclusion criteria were type 1 or 2 diabetes and a foot ulcer (duration > 3 weeks) and ulcer area (from 1 $cm^2$ to 4 $cm^2$). Measurements of the area of diabetic foot ulcer were carried out before treatment. Transcutaneous oxygen pressure ($TcpO_2$) was measured at adjacent site of ulcer. The healing wound was defined as complete wound closure within 12 weeks. Results: Average diabetic foot ulcer areas with healing and nonhealing wounds were $2.67{\pm}0.76$ and $2.59{\pm}0.75\;cm^2$, respectively. There was no significant difference in the wound area between the groups. Average foot $TcpO_2$ in healing and nonhealing wounds were $68.56{\pm}23.07$ and $30.98{\pm}16.66$ mmHg, respectively ($p$ <0.01). The rate of healing wound increased as $TcpO_2$ increased. In particular, $TcpO_2$ lower than 40 mmHg and higher than 40 mmHg showed the most significant difference (wound healing rates of 25% and 71%, respectively). Conclusion: Based on the results of the study, the minimal $TcpO_2$ value thought to be required for adequate wound healing in diabetic wounds (cut-off value) is 40 mmHg.

• Journal of the Korean Society for Library and Information Science
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• v.8
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• pp.73-101
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• 1981

Retrieval effectiveness is the principal criterion for measuring the performance of an information retrieval system. The effectiveness of a retrieval system depends primarily on the extent to which it can retrieve wanted documents without retrieving unwanted ones. So, ultimately, effectiveness is a function of the relevant and nonrelevant documents retrieved. Consequently, 'relevance' of information to the user's request has become one of the most fundamental concept encountered in the theory of information retrieval. Although there is at present no consensus as to how this notion should be defined, relevance has been widely used as a meaningful quantity and an adequate criterion for measures of the evaluation of retrieval effectiveness. The recall and precision among various parameters based on the 'two-by-two' table (or, contingency table) were major considerations in this paper, because it is assumed that recall and precision are sufficient for the measurement of effectiveness. Accordingly, different concepts of 'relevance' and 'pertinence' of documents to user requests and their proper usages were investigated even though the two terms have unfortunately been used rather loosely in the literature. In addition, a number of variables affecting the recall and precision values were discussed. Some conclusions derived from this study are as follows: Any notion of retrieval effectiveness is based on 'relevance' which itself is extremely difficult to define. Recall and precision are valuable concepts in the study of any information retrieval system. They are, however, not the only criteria by which a system may be judged. The recall-precision curve represents the average performance of any given system, and this may vary quite considerably in particular situations. Therefore, it is possible to some extent to vary the indexing policy, the indexing policy, the indexing language, or the search methodology to improve the performance of the system in terms of recall and precision. The 'inverse relationship' between average recall and precision could be accepted as the 'fundamental law of retrieval', and it should certainly be used as an aid to evaluation. Finally, there is a limit to the performance(in terms of effectiveness) achievable by an information retrieval system. That is : "Perfect retrieval is impossible."

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.742-756
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• 2008

Recently, it's increasing to use the applied technology related to the quantitative and qualitative growth of industry area. One of them is software to be used in industry area, and software is the most important part in using the industrial equipments. Therefore, the quality of software in the industrial devices determines the performance of the devices. At this time, it's inspired an evaluation and measurement of software quality to have within industrial equipment, and it's forming the research and development in domestic and foreign. In this paper, we constructed evaluation metrics based on ISO/IEC 12119, the International Standard for the general requirements of software and ISO/IEC 9126-2, the International Standard for the evaluation of software qualify characteristics and sub-characteritics, and for this accomplishment, It has been designed and developed industrial software international standard compatible approval system which approve a quality based on quality test result of industrial software using the ISO/IEC 14598-6 that international standard for organization of evaluation module.

• Journal of Nutrition and Health
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• v.39 no.2
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• pp.171-183
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• 2006

This study was conducted to examine dietary factors affecting bone status in the rural aged men. Quantitative ultrasound measurements (QUS) of bone, that may reflect certain architectural aspects of bone, have been shown to be associated with bone mineral density and fracture. Information of diet and anthropometry was collected in 164 aged men. Dietary intake data were obtained by 24-hour recall method. Measurements of the speed of sound (SOS, m/s), at distal radius, mid-tibia, phalanx, were performed using Omnisense 7000S analyzer (Sunlight Ltd., Tel Aviv, Israel). T-scores for bone SOS measurements at distal radius, mid-tibia and phalanx were 0.60, 0.03 and -0.42 respectively. The prevalence of osteopenia by use of the WHO criteria was 17.7% at the mid-tibia and 25.3% of the subjects at the distal radius. Age were negative association with bone SOS at three sites. Osteopenia group of radius were significantly lower in total foods and vegetable intakes than normal group. After adjusted for age, vegetable intakes were significantly and positively related to bone SOS at the radius. The bone SOS of the tibia were significantly and positively related to vegetable protein, iron, folate and vegetable intakes, but negatively related to fat intakes. Multiple regression analysis showed that bone SOS of tibia was positively associated with folate intakes. Vegetable intakes were positively associated with the bone SOS at three sites. These results indicate that the consumption of vegetables, sources of folate, may have a effect on bone status of men.

• The Journal of Industrial Distribution & Business
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• v.5 no.4
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• pp.31-42
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• 2014

Purpose - According to the applied studies knowledge, management implementation can improve organizational performance. The main objective of this study is to develop an understanding of critical success factors that enhance the successful implementation of knowledge management. Research design, data, and methodology - This study used Analytical Hierarchy Procedure (AHP), which is a multi-criteria decision making model that works on fuzzy logic. Using this method, researchers can find the proportion of success due to the contribution of the critical success factors (CSFs). Results - The results show that more than 70% of respondents indicate the possibility of success in knowledge management implementation. Further, the results show that top management support has the greatest relationship with the success of knowledge management implementation. This was followed by information technology, performance measurement, and culture, which had a high relation with knowledge management success. Process and activities have a moderate positive relation, while education and training has a low relation with success. Because of an inappropriate p-value, knowledge management strategies show no relation to the success of knowledge management in the Iranian health Industry. Conclusions - This study was conducted because of a critical issue in the Iranian health industry that indicated that a significant portion of the workforce would retire in 5 to 10 years. Most highly experienced and knowledge oriented employees would become eligible for retirement. Therefore, knowledge management is presented as a complete solution in the Iranian health sector.

• Korean Journal of Construction Engineering and Management
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• v.21 no.5
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• pp.38-45
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• 2020

Presently, safety management of facilities is conducted as a site-oriented safety inspection, but depending on the facilities, there are difficulties in access to the site, and the cost and time of inspection are inefficient due to excessive reliance on human resources. Therefore, the necessity of sensor-based safety management is being raised to ensure the safety of the facility at all times, and various studies on sensor safety management are being conducted, but the research on verification of practicality is still insufficient. Therefore, the improvement points were presented through analysis of domestic and international studies, and additional processes for setting sensor attachment location and threshold were derived by analyzing the H city sensor safety management process, and practicality of sensor safety management was verified through sensor data measurement values. It is expected that efficient, sensor-based facility safety management will be possible if clear criteria and ongoing practicality verification for the additional processes presented in this study should be carried out in the future.

• Korean Journal of Metals and Materials
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• v.50 no.2
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• pp.107-115
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• 2012

Direct laser melting (DLM) is a powder-based additive manufacturing process to produce parts by layer-by-layer laser melting. As the properties of the manufactured parts depend strongly on the deposited laser-melted bead, deposited layers obtained by the DLM process were characterized in this study. This investigation used a 200 W fiber laser to produce single-line beads under a variety of different energy distributions. In order to obtain a feasible range for the two main process parameters (i.e. laser power and scan rate), bead shapes of single track deposition were intensively investigated. The effects of the processing parameters, such as powder layer thickness and scan spacing, on geometries of the deposited layers have also been analyzed. As a result, minimum energy criteria that can achieve a complete melting have been suggested at the given powder layer thickness. The surface roughnesses of the deposited beads were strongly dependent on the overlap ratio of adjacent beads and on the energy distributions of laser power. Through microstructural analysis and hardness measurement, the morphological and mechanical properties of the deposited layers at various overlapped beads have also been characterized.