• Journal of Applied Reliability
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• v.11 no.2
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• pp.111-126
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• 2011

The clutch coil mounted on the automotive air conditioner is an important part which actuates the clutch to connect or disconnect the pulley and the compressor according to the climate control condition in an automobile. Here, it is generally required that the clutch coil should ensure the long term durability requirement, such as a warranty for the 10 years of field operation or 160,000 km driving, especially in a brand new item, and so forth. However, some difficulties have arisen in restoring its credibility, since domestic specifications for the part have not been yet unified. In order to ensure the reliability, test methods and assessment criteria should be standardized. Moreover, assessed lifetime under specific conditions and potential failure analysis would be important. In this study, lifetime test specifications for the clutch coil have been reviewed and methodological suggestions are provided to ensure reliability, utilizing a quality function deployment through the potential failure mode effect analysis.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1330-1338
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• 2024

Information on isotopic composition and geometric structure is necessary for identifying a true warhead. Nevertheless, such classified information should be protected physically or electronically. With a novel Hash encryption algorithm, this paper presents a Monte Carlo-based design of a neutron activation analysis verification module. The verification module employs a thermal neutron source, a non-uniform mask (physically encrypting information about isotopic composition and geometric structure), a gamma detector array, and a Hash encryption algorithm (for electronic encryption). In the physical field, a non-uniform mask is designed to distort the characteristic gamma rays emitted by the inspected item. Furthermore, as part of the Hash algorithm, a key is introduced to encrypt the data and improve the system resolution through electronic design. In order to quantify the difference between items, Hamming distance is used, which allows data encryption and analysis simultaneously. Simulated inspections of simple objects are used to quantify system performance. It is demonstrated that the method retains superior resolution even with 1% noise level. And the performances of anti-statistical attack and anti-brute force cracking are evaluated and found to be very excellent. The verification method lays a solid foundation for nuclear disarmament verification in the upcoming era.

• The Korean Journal of Archival Studies
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• no.7
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• pp.37-74
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• 2003

An Old document(Diploma) is a historical and unique record, so it must be collected, arranged, and preserved for research as soon as possible. Especially, for the effective use of the Old Document(Diploma), it is needed to arrange and describe the material systematically on the ground of modern archival theory. The Kyujanggak Archives in the Seoul National University has published 23 volumes of Old document(Diploma) material Old Document(Diploma). But they seem to cause the readers inconvenience, because the materials are classified and gathered only by genre, the titles or the orders of the materials are not standardized, and there is no description about the content of each Old document(Diploma). Jangseo-gak Library in The Academy of Korean Studies has also published the series of Old document(Diploma) material Old Document(Diploma) Collection. However the case is not different, since they are all mixed up with materials classified and gathered by genre, family, academy, or local school. And a great part of the materials have no titles and no description about the content of each Old document(Diploma), either. About the arrangement and description of the records, European and American archival science has established the theory of l)the principle of provenance, 2)the principle of original order, 3)levels of control, 4)collective description. These theories are valuable for the effective use of Old document(Diploma). On the viewpoint of the principle of provenance, Old document(Diploma) materials should not be classified by subject and genre, but by family and person. Then, the Old document(Diploma) materials, after collected by the unit of family or person on the viewpoint of the principle of provenance, should be arranged in their original order for more detailed arrangement and furthermore, for the work to find their relationship. This is so called the principle of original order. The hierarchical management of the Old document(Diploma) materials, for example, classifying by record group, sub-group, series, item and so on, is the concept of the levels of control, and comprehensive description of the each hierarchical structure is the concept of the collective description. Let's apply these archival theories to 34 pieces of the Chung, Man-Seok's material in the series of Old document(Diploma) material Old Document(Diploma). First, collect the Old document(Diploma) materials into Chung, Man-Seok's collection(the principle of provenance), which were scattered in the series classified by genre. Secondly, rearrange them chronologically(the principle of original order), and then we can find the comprehensive information about Chung, Man-Seok. For the hierarchical management of the Old document(Diploma) materials, we should establish a few concepts from the general, large group to specific, small item. The concepts can be organized as following; l)record group(Chung, Man-Seok record group) - 2)sub-group(personnel document, property document, family document, social activity document, political activity document, etc) - 3)series(gyoji-series, gyoseo-series, yuji-series etc. in the personnel document) - 4)folder(document with additions) - 5)item(one document). According to the the theory of the collective description, in the level of record group, there should be a collective description of Chung, Man-Seok's biography or a summary of record group. Similarly, there should be a collective description of a summary of sub-group in the level of sub-group and a summary of series in the level of series.

• The KIPS Transactions:PartD
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• v.9D no.2
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• pp.185-194
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• 2002

Most of mobile computing systems allow mostly read-only transactions from mobile clients for retrieving various types of Information such as stock data, traffic information and news updates. Since previous concurrence control protocols, however, do not consider such a particular characteristics, the performance degradation occurs when previous schemes are applied to the broadcast environment. In this paper, we propose OCC/UTF(Optimistic Concurrence Control with Update Transaction First) that is most appropriate for broadcast environment. OCC/UTF lets a query transaction, that has already read the data item which was invalidated by update transaction, read again the same data item without the abort of the query transaction due to non-serializability. Therefore, serializable order is maintained and the query transaction is committed safely regardless of commitment of update transactions. In OCC/UTF, Clients need not require server to commit their query transactions. Because of broadcasting the validation reports including values updated recently to clients, it reduces the overhead of requesting recent values from the server and the server need not also re-broadcast the newest values. As a result, OCC/UTF makes full use of the asymmetric bandwidth. It can also improve transaction throughput by increasing the commit ratio of query transactions as much as possible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.560-565
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• 2002

In this paper, we implemented the sign board system that displays user's image, user's sentence, the information from DARC an[1 information based position by GPS module for vehicle. The existing sign board is displaying only user's image and sentence. Or other existing sign board is displaying the information via CDMA network. However, our system is also able to display the user's message like other system and gain the information more cheap by DARC. This system consists of 6 parts. The DARC control part classes the DARC information - news, weather, stock and time. The GPS control part gains moment and item to display with calculating the information of global position, direction, speed and satellite. The LED control part has two buffers to store and handle the image. The buffers help the system display various effected images on LED board. An external memory card includes the location based data, the option file and the displayed data files. The data files are stored by FAT 16 with the folder structure on external memory card. The USB controls the communication with PC. PC programs can control and monitor this system. This system is using G72l voice file format, for casting the information. This system was established at the vehicle and we monitored this system. The system displayed the DARC data , user's data and the location based data on the LED board, successfully.

• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.103-110
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• 2006

The present study is designed to analyze reliability and validity of the instruments used to measure job stress of radiological technologists mainly by means of the questionnaires from 'Korean edition of NIOSH check list'. The subjects of this study are 890 radiological technologists active at 44 general hospitals in 16 provinces and cities across the country. The item-total reliability revealed that 10 factors in 6 are the major causes of stress in job life of radiological technologists. The measuring instrument proved to be valid with reliability coefficient of internal consistency by factors being more than 0.7. The factors found to be applicable herewith include limit and authority of job (0.73), cohesion within departments (0.86), resources control (0.81), mental requirements (0.85), job load (0.82), and job stability (0.72). When job autonomy item of causes are modified for proper use to radiological technologists, the measuring instruments are expected to show high reliability. It seems, however, necessary to develop a measuring instrument to analyze and use the validity of related measuring instruments since the reliability here was rated low, with statistical coefficients lower than 0.7 in such factors as job management (0.57), conflicts within departments (-1.13), sense of responsibility for patients (0.66) and usage of education (0.26). As this study was intended to examine reliability and validity of the concepts related to measurement of job stress on the part of radiological technologists, it nay not be proper to apply the results of this study to general use, but is advised to utilize them as basis for developing instruments to verify reliability and validity by comparing with and analyzing other measuring instruments.

• The KIPS Transactions:PartD
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• v.18D no.6
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• pp.451-460
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• 2011

The ability to trace change history and dependency relations of software artifacts which are continuously changed has been recognized as an important factor that support quality management activities such as verification, validation, and testing in software system development process. General software configuration management systems provide tracing information for artifacts only within the configuration management system, and it does not go further to changes that occur within personal workspace. This paper provides a solution that helps tracing down not only changes of configuration items but also change history of artifacts existent in personal workspace through the integration of configuration management system and personal workspace. Furthermore, in cases of artifacts which are included in a configuration item, this paper provides a solution that support tracing dependency relations between the artifacts by identifying their version links. For the integration of configuration management system and personal workspace, a revision of configuration item is connected to the artifact's version of the workspace by the tagging mechanism, and traceability for change history and dependency relations of artifacts can be managed more effectively through integrated change process.

• Journal of Technologic Dentistry
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• v.37 no.3
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• pp.169-178
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• 2015

Purpose: This study was to investigate usage satisfaction of multi type handpiece with equipped air-jet function Methods: The subjects of this study through the survey was conducted for fifty-nine dental technicians in Daegu and Gyeongsangbukdo from the May 7 to 19, after the June 23 to July 4 2014. The survey was about the function and quality through user testing environment by cutting zirconia specimens using appliance for zirconia. The collected date was analyzed by the statistical program SPSS Win Ver 19.0 for the satisfaction of handpiece and control system. To test for significance on each item, p<0.05 had been decided a standard. General characteristics and relationship between the handpiece and control system was performed correlation analysis. Results: The results of this study is as follows. 35 dental technicians had 1~2 years career in zirconia part as the highest 59.3%, 95% of subjects expected that the prospects for the zirconia material have bright prospects. The satisfaction of multi type handpiece and control system design and function showed a significant difference. Subjects satisfied with the design and function of the multi type showed negative correlation with those of Standard. The satisfaction of multi type handpiece showed 3.37 points of air jet, 3.05 points of noise level, 2.69 points of water flow rate, and 1.98 points of cruise function. Sample differences in all parameters showed a statistically higher difference. Conclusion: High-speed cutting mechanism of multi-type is recommended working with zirconia materials and the multi-type unit combined handpiece motor, air-turbine and air-gun will be expected the increase of user due to the high satisfaction of air jet.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.339-350
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• 2003

The Part 7 of MPEG-21, called Digital Item Adaptation, aims at an interoperable transparent access of multimedia contents in heterogeneous environments. This standard facilitates the development of Universal Multimedia Access (UMA) systems, which adapt the rich multimedia contents to provide user the best possible presentation under the constraints of various terminals and network connections. Content adaptation has two major aspects: one is modality conversion that converts content from one modality (e.g. video) to different modalities (e.g. image) the other is content scaling that changes the titrates (or qualities) of the contents without converting their modalities. At the output of adaptation process, the highly-subjective qualities of adapted contents nay vary widely with respect to point-of-views of different providers and different users. So, user should have some control on the adaptation process. In this paper, we describe two description tools of user characteristics, the presentation priority preference and the modality conversion preference, which allow user to have flexible choices on the qualities and modalities of output contents. We also present a systematic approach to integrate these user preferences into the adaptation process. These description tools are developed in the process of MPEG-21 standardization.

• Journal of Drive and Control
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• v.16 no.1
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• pp.14-21
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• 2019

Axial piston pump is a significant part in wheeled armored vehicle, for generating hydraulic power of vehicle power system. The Axial Piston Pump is a high-performer, core functional item that is developed and applied to most of the military models in the development of military weapon systems. However, in the case of military equipment, there are conditions of limited size and weight required depending on the operating conditions and the operating environment. Under these conditions, it is required that the performance and the environmental resistance are verified to exert the required output. A unique technology is needed for the development of such equipment both in the present and in the future. Therefore, in this study, mathematical modeling of an axial piston pump is presented as a basic data for securing proprietary technology. In addition, a simulation model is designed and compared with the models of six kinds of pistons through simulation. It was established that when the number of pistons of the axial piston pump, which is the development objective, is seven, the model is suitable for the wheeled armored vehicle.