• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06a
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• pp.68-73
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• 1996

• Advances in aircraft and spacecraft science
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• v.4 no.6
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• pp.651-677
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• 2017

For the past ten years' efforts have been made to introduce environmentally-friendly "green" electric-taxi and maneuvering airplane systems. The stated purpose of e-taxi systems is to reduce the taxiing fuel expenses, expedite pushback procedures, reduce gate congestion, reduce ground crew involvement, and reduce noise and air pollution levels at large airports. Airplane-based autonomous traction electric motors receive power from airplane's APU(s) possibly supplemented by onboard batteries. Using additional battery energy storages ads significant inert weight. Systems utilizing nose-gear traction alone are often traction-limited posing serious dispatch problems that could disrupt airport operations. Existing APU capacities are insufficient to deliver power for tractive taxiing while also providing for power off-takes. In order to perform comparative and objective analysis of taxi tractive requirements a "standard" taxiing cycle has been proposed. An analysis of reasonably expected tractive resistances has to account for steepest taxiway and runway slopes, taxiing into strong headwind, minimum required coasting speeds, and minimum acceptable acceleration requirements due to runway incursions issues. A mathematical model of tractive resistances was developed and was tested using six different production airplanes all at the maximum taxi/ramp weights. The model estimates the tractive force, energy, average and peak power requirements. It has been estimated that required maximum net tractive force should be 10% to 15% of the taxi weight for safe and expeditious airport movements. Hence, airplanes can be dispatched to move independently if the operational tractive taxi coefficient is 0.1 or higher.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.433-452
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• 2014

Objective: The aim of this study is to give ergonomists the brief summary of the recently published ISO standards on human-system interaction and tips for application of the standards. Background: Standard developers did hard work on developing a standard in a concise manner. But most of standards are often bulky in volume. Readers of the standards are difficult to catch key points from the voluminous contents of standards and intermingle among them. Method: Focused on newly developed display/control technology, this study reviewed the 14 ISO standards on human-system interaction published during 2008-2013 and summarized key points from them. Results: Schematic diagrams and tables concisely illustrated the processes, procedures, dimensions, or best practices recommended by the standards concerning conception, design, and usability testing for consumer products. Conclusion: The standards provided the minimum level of requirements on design and evaluation on the physical input devices, electronic displays, and control interfaces based on the current state of technology. But the minimum requirements specified in the standards nowadays become mandatory ergonomic requirements in global trade world. Application: Ergonomists can take a quick and broad view on international standardization activities on newly developed display/control technology from this summary study.

• Journal of Korean Public Health Nursing
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• v.31 no.3
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• pp.421-435
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• 2017

Purpose: Public health centers (PHCs) provide a variety of healthcare services according to the Regional Public Health Act (RPHA). We aim to analyze the changes in public healthcare services according to the legislation and the number of public health nurse (PHN) involved in the service, and propose an alternative to effectively distribute the public health nursing workforce for protecting the health rights of people. Methods: This is a review study that deduced the results from literature review. Results: During the revision of the PHC law to the RPHA, several services were added. Health related laws have forced the PHCs to provide services for these legislations. Consequently, the workload on the PHNs has been increasing. However, the PHNs have been consistently lacking. In 2017, there are 16.2 full-time nurses per center. Furthermore, About 50% of the PHCs are not meeting the minimum requirements of licensed or qualified health professional workforce outlined in 1997. In addition, 43% of the nurses in the PHCs are part-time nurses. Conclusion: We suggest that the minimum requirements of health professional workforce should be modified to reflect the increase in the workload of PHNs, and a legislation to enforce PHCs to fulfill these requirements is needed.

• Journal of Information Processing Systems
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• v.10 no.3
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• pp.412-428
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• 2014

Request oriented sensor networks have stricter requirements than conventional event-driven or periodic report models. Therefore, in this paper we propose a minimum energy data aggregation (MEDA), which meets the requirements for request oriented sensor networks by exploiting a low power real-time scheduler, on-demand time synchronization, variable response frame structure, and adaptive retransmission. In addition we introduce a test bed consisting of a number of MEDA prototypes, which support near real-time bidirectional sensor networks. The experimental results also demonstrate that the MEDA guarantees deterministic aggregation time, enables minimum energy operation, and provides a reliable data aggregation service.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.154-161
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• 2000

A series of soil bin experiment was carried to investigate the effects of rotary blade shape, rotational direction of rotary blade, number of blade and soil cutting disk blade on the characteristics of partial tillage. Among the three types of rotary blades, rotary blade for cultivator was considered to be proper for partial tillage of direct seeder considering the torque requirements and ratio of soil breaking. There is no need to attach so many blades to the rotary shaft. Four rotary blades were enough for efficient partial tillage by rotary tiller. Though soil cutting disk blade assisted the better formation of seedbed furrow, attachment of the soil cutting disk blade increased torque requirements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2626-2634
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• 1997

The purpose of multicasting is to reduce the network costs for transmitting the same traffic to multiple destinations. In this paper, an efficient delay-bounded multicasting routing algorithm is proposed, which satistifies the network conditions of cost minimization and can adjust the dynamic events, such as 'leave and/or join ones' from the multicast group. Also, our algorithm is designed for various network requirements such as the efficiet dynamic group support, high-quality data distribution, and adaptability to variable situation. After the delay tolerance and the maximum group size are determined according to network state and requirements for delay and cost, the dynamic delay-bounded multicast tree is constructed using partial multicast routing. We evaluate the performance of the proposed algorithm by running simulations on randomly generated test networks using a Sun Sparc 20 workstation. We were able to obtain good simulation resutls, which means solutions that lies between the minimum cost solution and the minimum delay one.

• Journal of Auto-vehicle Safety Association
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• v.12 no.4
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• pp.48-53
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• 2020

This paper describes in work which is currently underway to the minimum safety performance requirements and test methods of V2V based on IEEE 802.11p in vehicle level like below. - The ranges and positions at static and driving condition of vehicle for BSM (Basic safety message) - Various road conditions such as straight road, crossroad, slope-way Based on this study, We will define the minimum safety performance requirements and test methods of V2V in vehicle considering various road conditions.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.631-636
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• 2002

It is common in multistory flat-plate structures that newly cast slabs are supported by a number of previously cast floors. Then the weight of newly cast slabs is imposed on shored previously cast floors as load, and this load may be large as double as dead load. Because early-age construction loads cause large immediate deflection and creep deflection with cracks, this loads influence long-term behavior of slabs. In current provision, the minimum thickness is required to satisfy serviceability But this minimum thickness based on historical precedent is determined by span length, therefore the minimum thickness of current provision can not includes properly the effect of construction scheme including the number of shored floors and construction cycle. In the present study, a minimum thickness criterion, which includes the effect of concrete strength, geometry of slabs and construction scheme, was developed from computer-based iteration using deflection calculation procedure of current code method.

• Journal of the Korean housing association
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• v.20 no.3
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• pp.47-58
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• 2009

Providing an adequate housing to the socially underprivileged with a weak economic base is the most difficult task of housing policies. Korea established minimum housing standards and has used them for housing policies. However, the level of Korean minimum housing standards is far lower than that of foreign minimum housing standards. Thus, this study made a comparative analysis of Korean minimum housing standards with foreign housing standards in various aspects in order to guarantee housing quality of the socially underprivileged in Korea. In particular, the floor area and ratio of small lease homes are minutely examined to present the actual housing standard of the socially underprivileged. The level of Korean minimum housing standards suggested in this paper is very close to that of Japanese minimum housing standard, which is 37.95 $m^2$ for a 3 member family and just above Chombard de Lauw's pathological limit (36.03 $m^2$). As this research is specifically focused on the establishment of minimum floor area standards for the socially underprivileged, further research should be made in consideration of more specific requirements of various groups for the socially underprivileged.