• IEMEK Journal of Embedded Systems and Applications
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• v.1 no.2
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• pp.104-112
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• 2006

ZigBee is the emerging industrial standard for ad hoc networks based on IEEE 802.15.4. It is used for low data rate and low power wireless network applications. Expected applications of ZigBee include wireless sensor networks for remote monitoring, home control, and industrial automation. Since one of the most important design goals of ZigBee is to reduce the installation and running costs, the ZigBee stack is embedded in the cheap and small micro-controller unit. The hierarchical routing algorithm is used for ZigBee end devices which have very limited resources. Using the block addressing scheme, end devices can send data to the destination without a routing table. However, hierarchical routing has the problem that the packets follow the tree hierarchy to the destination even if the destination is located nearby. In this paper, we propose a scheme to improve the hierarchical routing algorithm in ZigBee networks by employing the neighbor table that is originally used together with the routing table. We suggest selecting the neighbor node that has the minimum remaining hops to the destination as the next hop node. Simulation result shows that the proposed scheme saves more than 30% of the hop counts compared with the original hierarchical routing.

• Journal of Digital Contents Society
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• v.13 no.4
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• pp.491-500
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• 2012

In this paper, a new loopback BIST structure which is effective to test RF transceiver chip and LNA(Low Noise Amplifier) in the chip is presented. Because the presented BIST structure uses a baseband processor in the chip as a tester while the system is under testing mode, the developed test technique has an advantage of performing test application and test evaluation in effectiveness. The presented BIST structure can change high frequency test output signals to a low frequency signals which can make the CUT(circuits under test) tested easily. By using this technique, the necessity of RF test equipment can be mostly reduced. The test time and test cost of RF circuits can be cut down by using proposed BIST structure, and finally the total chip manufacturing costs can be reduced.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.127-131
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• 2006

There are being a lot of studies for achievement of high speed Dehydration, high-strength and Lightweight of washing machine in the latest washing machine business. It is essential that Press-joining Strength of Spin Drum Seaming division is improved .to attain that target. Generally, we are using Mechanical press-joining by Seaming and T.I.G (Tungsten Inert Gas) welding among part joint method. Mechanical press-joining method that is mainly using for Stainless Steel (STS430) Drum have lots of merit that consumption of energy is low more than welding and production costs cut down and generation of the corrosion is solved by removing weld zone defect and materials having different properties are enable to join without special equipment. But, it is difficult to realize joint strength required at high speed operation because joint strength of mechanical press-joining method is low remarkably in comparison with welding. Also, there are a lot of analysis difficulties and very limited research is under way due to the dynamic factor such as multistage plastic working, elastic recovery, residual stress etc. The results of this study show optimal joining condition for mechanical press-joining by performing lots of tensile joining strength test with various specimen under multi-change of important design factor such as seaming width, bead area and bead depth etc.

• Journal of Families and Better Life
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• v.27 no.2
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• pp.191-201
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• 2009

The Korean Government has recently prepared the comprehensive five-year basic plan (2006-2010) to deal with low fertility and population ageing. The basic plan aims at recovering the fertility rate to the appropriate level and improving the social and economic systems in preparation for the aged society. The main objective of this study was to examine the effects of fertility policies on childbirth by birth order. The data came from 1,729 adults who gave birth to babies in 2007 and 991 adults as the control group. The serial logistic regression analyses revealed that establishing the health and nutrition system for maternity and children, and expanding of tax and social insurance benefit were effective policy measures to increase childbirths of first children, while the policy measures establishing the health and nutrition system for maternity and children, supporting for daycare and pre-school education, and work-life balance were effective to childbirths of second or third children in 2007. However, the policies of supporting for costs of test-tube baby and expanding childcare infra didn't have any significant influences on childbirths in 2007. The implications of study results were discussed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.243-246
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• 2010

Recently, global warming problem is a major issue in international community. The carbon dioxide ($CO_2$) emissions in the construction industry is one of the main factors causing a global warming problem. Accordingly, various researches on $CO_2$ emissions caused by the construction industry is needed and construction methods which is low $CO_2$ emissions should be developed. In this study, $CO_2$emission cost is compared with roof waterproofing types in construction phase. As a result, the $CO_2$ emission costs of asphalt waterproofing is the highest. This research is to provide basic information for selecting appropriate construction methods in aspect of low $CO_2$ emission cost.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.4
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• pp.373-380
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• 1997

In order to implement the real-time operating systems for robot controller, this paper proposes a systematic method for implementing the real-time kernel under the DOS environment. So far, we designed the robot control software and its own operating system simultaneously. Though robot operating systems have simple structure, it allows the developer to have a surplus time and effort to implement complete robot systems. In addition to this, in most cases of this type, operating systems does not support multitasking function, thus, low level hardware interrupts are used for real-time execution. Subsequently, some kinds of real-time tasks are hard to implement under this environment. Nowadays, the operating systems for robot controller requires multitasking functions, intertask communication and task synchronization mechanism, and rigorous real-time responsiveness. Thus, we propose an effective and low costs real-time systems for robot controller satisfying the various real-time characteristics. The proposed real-time systems are verified through real implementation.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.451-453
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• 2007

This paper describes the design of an asynchronous implementation of a sensor network processor. The main purpose of this work is the reduction of power consumption in sensor network node processors and the research presented here tries to explore the suitability of asynchronous circuits for this purpose. The Handshake Solutions toolkit is used to implement an asynchronous version of a sensor processor. The design is made compact, trading area and leakage power savings with dynamic power costs, targeting the typical sparse operating characteristics of sensor node processors. It is then compared with a synchronous version of the same processor. Both versions are then compared with existing commercial processors in terms of power consumption.

• Journal of Korean Academy of Rural Health Nursing
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• v.2 no.2
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• pp.111-119
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• 2007

Purpose: In this study consumers' preference for housing for elderly people was analyzed as well as the recognition by elders of silver town facilities, and their preference for service provided by silver town. The study was done to provide basic data for the development of silver town facilities that are low in cost and high in efficiency. Methods: A sample research was used in this study to analyze the understanding of old age, silver town, and service preference. Results: First, interest and intention to live in silver town was very positive, however low cost was also preferred and that is quite different to current silver towns of Korea. Second, women have more understanding of, requests for, and intention to move into silver town facilities than men. Women's demands for silver town facilities must be reflected in the development strategy of silver towns. Third, the most important part of activating silver town facilities is price strategy. Government political support is required in order to keep silver town move-in costs affordable. Fourth, silver towns must function as total service complex towns. Conclusion: This study is meaningful as efficient operation of silver town is suggested rather than facility degradation to achieve price reduction. This result is important to the development of silver towns based on consumer preference, as it suggests a development direction that is focused on securing differentiated services and programs.

• The Journal of the Korean life insurance medical association
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• v.26
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• pp.21-30
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• 2007

ECG is included in certain medical examinations of insurance application, ECG has low specificity and sensitivity. So ECG is not usually used to diagnose specific diseases. But, ECG is not invasive and costs low. So ECG is usually used in underwriting. Actually in underwriting we meet various ECG patterns and diagnosises. Understanding of various ECG patterns is different between insurance medicine and clinical medicine. So We have to learn various ECG patterns and effects on mortality and morbidity. First considerations of ECG readings are age, sex, blood pressure, family history, smoking historyalcohol history and hyperlipidemia. These are predictors for possibility of disease. Also it is important to review recording ECG with proper skill. In this review I consider several ECG diagnosises that we meet frequently, which is, LVH, RVH, ST abnormalities, LBBS, RBBB, A-B blocks, several kinds of arrhythmia. We have to consider long term mortalities and morbidities of specific ECG patterns although applicants have no symptom and sign. And then we have to make underwriting manual according to specific ECG diagnosises and patterns and underwrite precisely ECG patterns according to insurance products. Nowadays coronary heart disease and other heart diseases are increasing in Korea. So we have to learn various ECG patterns and research mortalities and morbidities of abnormal ECG patterns. Also we have to apply to more broad, precise underwriting skills about ECG patterns and diagnosises.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.3
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• pp.123-128
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• 2008

Ti-6Al-4V alloy is a critical strategic metal used in aerospace structure due to the high specific strength, toughness, durability, low density, corrosion resistance. Examples of application of this alloy are airframe structural components, aircraft gas turbine disks and blades. Forming of this alloy is not easy due to its high strength and low formability. However, this alloy shows superplastic properties that allow for large plastic deformation under certain conditions. Combination of superplastic forming and diffusion bonding(SPF/DB) processes of this alloy has been widely used to replace mechanically fastened structures with reduced weight and fabrication costs. In this study, superplastic forming/diffusion bonding technology has been developed for fabricating lightweight sandwich panels with Ti-6Al-4V alloy. The experimental results show the forming of titanium lightweight sandwich structure is successfully performed from 3 and 4 sheets of Ti-6Al-4V.