• Journal of Technology Innovation
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• v.26 no.3
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• pp.37-68
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• 2018

Since the 20th century, automobiles, which are the most common means of transportation, have been evolving as the use of electronic control devices and automotive semiconductors increases dramatically. Automotive semiconductors are a key component in automotive electronic control devices and are used to provide stability, efficiency of fuel use, and stability of operation to consumers. For example, automotive semiconductors include engines control, technologies for managing electric motors, transmission control units, hybrid vehicle control, start/stop systems, electronic motor control, automotive radar and LIDAR, smart head lamps, head-up displays, lane keeping systems. As such, semiconductors are being applied to almost all electronic control devices that make up an automobile, and they are creating more effects than simply combining mechanical devices. Since automotive semiconductors have a high data rate basically, a microprocessor unit is being used instead of a micro control unit. For example, semiconductors based on ARM processors are being used in telematics, audio/video multi-medias and navigation. Automotive semiconductors require characteristics such as high reliability, durability and long-term supply, considering the period of use of the automobile for more than 10 years. The reliability of automotive semiconductors is directly linked to the safety of automobiles. The semiconductor industry uses JEDEC and AEC standards to evaluate the reliability of automotive semiconductors. In addition, the life expectancy of the product is estimated at the early stage of development and at the early stage of mass production by using the reliability test method and results that are presented as standard in the automobile industry. However, there are limitations in predicting the failure rate caused by various parameters such as customer's various conditions of use and usage time. To overcome these limitations, much research has been done in academia and industry. Among them, researches using data mining techniques have been carried out in many semiconductor fields, but application and research on automotive semiconductors have not yet been studied. In this regard, this study investigates the relationship between data generated during semiconductor assembly and package test process by using data mining technique, and uses data mining technique suitable for predicting potential failure rate using customer bad data.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.461-472
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• 2017

The purpose of this study is to analyze the current status and condition of children's playgrounds in K which parents recognize as in Gyeonggi-do and provide basic data for the qualitative environment for daily outdoor play of young Children. To do so, a survey of 269 parents living in Gyeonggi-do was conducted and reconstructed based on the advanced research related to outdoor play. Also it was evaluated and revised after consultation with 3 children education specialists. The repossessed questionaries were frequency-analyzed with SPSS 20.0 program. The result of the analysis on outdoor playgrounds is in the following. First of all, it was analyzed that parents required 1 or 2 hours for their children to play outdoors in a type of "forest playgrounds." Moreover, they said that it was really important for the children to feel "interesting and funny" during the outdoor play, and they recognized that the play would be helpful for the children's socialization. However, they felt that a risk factor of the outdoor play was "a vehicle risk in streets." Secondly, the study suggested that there were outdoor playgrounds around parents' houses, and a type of the outdoor play was "a playground installed in the apartment complex." Furthermore, most of the parents weren't satisfied with the outdoor play because the apartment neglected the management of the playgrounds, and there were no playing facilities that were good enough to derive children's curiosity and adventurous spirit. The result also showed that most of the children played outdoors with "their mothers," and they participated in indoor activities, especially playing a game or watching TV rather than outdoor activities after attending a children educational institute. Lastly, when it comes to areas of outdoor play to be improved, it was necessary to "expand playgrounds that children can use for each season," build "safe playgrounds" for a type of the outdoor play," provide "playing spaces" for a spatial type, and "control vehicles around the playgrounds and deal with dangerous things" to prevent safety accidents. The result can expand the understanding of outdoor play for Young Children and offer discussions about the relevant organizations and studies.

• Journal of the Korean Professional Engineers Association
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• v.28 no.4
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• pp.54-75
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• 1995

This synthesis has been prepared from a review of literature on Truck Escape Ramps technology and a survey of current practice by state department of transportation. Their locations have been determined usually from a combination of accident experience and en-gineering judgement, but new tools are emerging that can identify needs and sites without waiting for catastrophic accidents to happen. The Grade Severity Rating Systems holds promise in this regard. Design Procedures for truck excape ramps continue to evolve. Gravel arrester beds are clearly the preferred choice across the country Rounded aggregate, uniformly graded in the approximate size range of 13 to 18mm. Tech-nical publications typically have dassified TER types as paved gravity, sandpile, and ar-rester bed ramps. The design speed for vehicle entry into the ramp in critical to the deter-mination of ramp length. An escape ramp should be designed for a minimum entry speed of 130km/hr, a 145km/hr design being preferred. The ramps should be straight and their angle to the roadway align-ment should be as possible. The grade of truck escape ramps show the adjustment of ramp design to local topography, such as the tradeoff of ramp length against earthwork requirements. A width of 9 to 12m would more safety acommodate two or more outof con-trol vehicles. Reguarding comments on the most effective material, most respondents cited their own specification or referred to single graded, rounded pea gravel. The consensus essentially Is that single graded, well -rounded gravel is the most desirable material for use in arrester beds. The arrester beds should be constructed with a minimum aggregate depth of 30cm. Successful ramps have used depths between 30 and 90cm.

• The Korean Journal of Air & Space Law and Policy
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• v.5
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• pp.101-118
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• 1993

Generally there is no law and liability system which applies particulary to commercial space ventures. There are several international treaties and national statutes which deal with space ventures, but their impact on the liability of commercial space ventures has not been significant. Every state law in the United States will impose both tort and contract liability on those responsible for injuries or losses caused by defective products or by services performed negligently. As with the providers of other products and services, those who participate in commercial space ventures have exposure to liability in both tort and contract which is limited to the extent of the resulting damage The manufacturer of a small and cheap component which caused a satellite to fail to reach orbit or to operate nominally has the same exposure to liability as the provider of launch vehicle or the manufacturer of satellite into which the component was incorporaded. Considering the enormity of losses which may result from launch failure or satellite failure, those participated in commercial space ventures will do their best to limit their exposure to liability by contract to the extent permitted by law. In most states of the United States, contracts which limit or disclaim the liability are enforceable with respect to claims for losses or damage to property if they are drafted in compliance with the requirements of the applicable law. In California an attempt to disclaim the liability for one's own negligence will be enforceable only if the contract states explicitly that the parties intend to have the disclaimer apply to negligence claims. Most state laws of the United States will refuse to enforce contracts which attempt to disclaim the liability for gross negligence on public policy grounds. However, the public policy which favoured disclaiming the liability as to gross negligence for providers of launch services was pronounced by the United States Congress in the 1988 Amendments to the 1984 Commercial Space Launch Act. To extend the disclaimer of liability to remote purchasers, the contract of resale should state expressly that the disclaimer applies for the benefit of all contractors and subcontractors who participated in producing the product. This situation may occur when the purchaser of a satellite which has failed to reach orbit has not contracted directly with the provider of launch services. Contracts for launch services usually contain cross-waiver of liability clauses by which each participant in the launch agrees to be responsible for it's own loss and to waive any claims which it may have against other participants. The crosswaiver of liability clause may apply to the participants in the launch who are parties to the launch services agreement, but not apply to their subcontractors. The role of insurance in responding to many risks has been critical in assisting commercial space ventures grow. Today traditional property and liability insurance, such as pre-launch, launch and in-orbit insurance and third party liability insurance, have become mandatory parts of most space projects. The manufacture and pre-launch insurance covers direct physical loss or damage to the satellite, its apogee kick moter and including its related launch equipment from commencement of loading operations at the manufacture's plant until lift off. The launch and early orbit insurance covers the satellite for physical loss or damage from attachment of risk through to commissioning and for some period of initial operation between 180 days and 12 months after launch. The in-orbit insurance covers physical loss of or damage to the satellite occuring during or caused by an event during the policy period. The third party liability insurance covers the satellite owner' s liability exposure at the launch site and liability arising out of the launch and operation in orbit. In conclusion, the liability in commercial space ventures extends to any organization which participates in providing products and services used in the venture. Accordingly, it is essential for any organization participating in commercial space ventures to contractually disclaim its liability to the extent permitted by law. To achieve the effective disclaimers, it is necessary to determine the applicable law and to understand the requirements of the law which will govern the terms of the contract. A great deal of funds have been used in R&D for commercial space ventures to increase reliability, safety and success. However, the historical reliability of launches and success for commercial space ventures have proved to be slightly lower than we would have wished for. Space insurance has played an important role in reducing the high risks present in commercial space ventures.

• Journal of Veterinary Clinics
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• v.29 no.3
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• pp.213-219
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• 2012

The recombinant bovine somatotropin (rbST) has been used for increasing milk production of dairy cows without adverse health effects. This study was conducted to compare effects of supplementation with $Boostin^{(R)}$-250 containing 250 mg of rbST on milk production with those of $Posilac^{(R)}$ and $Boostin^{(R)}$-S. And safety of rbST supplementation on target animals was also observed. Each twenty-five lactating dairy cows were assigned randomly to one of four groups. $Boostin^{(R)}$-250 and vehicle (control) were administered weekly. $Boostin^{(R)}$-S and $Posilac^{(R)}$ were administered two week intervals. Milk yield, milk components, milk somatic cell count, health status, and body condition score of cows were examined. Supplementation with $Posilac^{(R)}$, $Boostin^{(R)}$-S, and $Boostin^{(R)}$-250 induced more milk yield than control group by 2.9 kg/day (12.3%), 4.2 kg/day (17.9%), and 4.1 kg/day (17.4%), respectively. There was a significant difference in milk yield among three rbST treatment groups and control group (${\alpha}$ = 0.05). The rbST supplementation did not increase the incidence of clinical mastitis and milk somatic cell counts. Supplementation with rbST did not significantly affect milk components (milk fat, protein, and solid not fat). The rbST supplementation of the dairy cows after peak milk yield did not cause negative effect on BCS. However, some cows less than 100 days in milking had decreased BCSs after rbST supplementation. In conclusion, milk production in 250 mg of rbST administered cows every week was similar to that of 500 mg of rbST administered cows every 2 weeks. And supplementation of 250 mg of rbST every week could reduce metabolic stress in cows.

• Korean Security Journal
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• no.21
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• pp.155-175
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• 2009

RFID that provide automatic identification by reading a tag attached to material through radio frequency without direct touch has some specification, such as rapid identification, long distance identification and penetration, so it is being used for distribution, transportation and safety by using the frequency of 125KHz, 134KHz, 13.56MHz, 433.92MHz, 900MHz, and 2.45GHz. Also it is one of main part of Ubiquitous that means connecting to net-work any time and any place they want. RFID is expected to be new growth industry worldwide, so Korean government think it as prospective field and promote research project and exhibition business program to linked with industry effectively. RFID could be used for access control of person and vehicle according to section and for personal certify with password. RFID can provide more confident security than magnetic card, so it could be used to prevent forgery of register card, passport and the others. Active RFID could be used for protecting operation service using it's long distance date transmission by application with positioning system. And RFID's identification and tracking function can provide effective visitor management through visitor's register, personal identification, position check and can control visitor's movement in the secure area without their approval. Also RFID can make possible of the efficient management and prevention of loss of carrying equipments and others. RFID could be applied to copying machine to manager and control it's user, copying quantity and It could provide some function such as observation of copy content, access control of user. RFID tag adhered to small storage device prevent carrying out of item using the position tracking function and control carrying-in and carrying-out of material efficiently. magnetic card and smart card have been doing good job in identification and control of person, but RFID can do above functions. RFID is very useful device but we should consider the prevention of privacy during its application.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.815-825
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• 2017

Visibility of lane marking is impaired at night or in the rain, which thereby threatens traffic safety. Recently, various studies and technologies have been developed to improve lane marking visibility, such as the extension of lane marking life expectancy (up to 1.5 times), improvement of lane marking equipment productivity, improvement of lane marking visibility by applying phosphorescent material mixed paint. Cost-benefit analysis was performed with considering various benefit items that can be expected. About 45% of traffic accidents would be prevented by improving lane marking visibility. Additionally, accident reduction benefit and traffic congestion reduction benefit were calculated as much as 246 billion KRW per year and 12 billion KRW per year, respectively, by reducing repaint cycle due to enhanced durability. 45 billion KRW per year is expected to reduced with improved lane detection performance of autonomous vehicle. Meanwhile, total increased cost when introducing phosphorescent material mixed paint to 91,195km of nationwide road is identified as 1922 billion KRW per year. However, economic feasibility could not be secured with 0.16 of cost-benefit ratio when applied to the road network as a whole. In case of "Accident Hot Spot" analyzing section window (400m), one or more fatality or two or more injured (one or more injured in case of less than 2 lanes per direction) per year were caused by pavement marking related accident, economic feasibility was secured. In detail, 3.91 of cost-benefit ratio is estimated with comparison of the installation cost for 5,697 of accident hot spot and accident reduction benefit. Some limitations and future research agenda have also been discussed.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.33-43
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• 2007

Because usually signal controllers on the crosswalks of mid-block provide pedestrian signals every cycle based on the fixed signal plan, pedestrian signals are provided even when there is no pedestrian demand. Consequently, signal is operated inefficiently and this may cause drivels to experience useless delay or violate the signal. Even though recently pushbuttons have been installed to improve the efficiency of pedestrian signal control in the crosswalks of mid-block and the pedestrian safety. they are not spread out national-wide in Korea because of the cost of the pushbutton equipments and the lack of an acknowledgement of the efficiency of the pushbutton. In this study, the effectiveness of the pushbutton on saving the vehicle delay was verified through before and after study in 4 study sites using a traffic micro-simulation model, VISSIM. To evaluate the viability of the pushbutton, a benefit/cost analysis was also performed for 4 study sites. It was found that B/C ratio of all of 4 study sites was greater than 1. The sensitivity analysis for the traffic volume and pedestrian volume were performed to identify the impact of the both volume on the operation of pushbutton. And, a benefit/cost analysis was performed for all scenarios. It was found that when the pedestrian volume is greater than 90ped/h, the pedestrian signal was operated same as the fixed signal plan. That is, there is no benefit of pushbutton at all once the pedestrian volume is greater than 90ped/h. When the pedestrian volume is equal to or less than 90ped/h and the traffic volume is greater than 2,500veh/h, B/C ratio is greater than 1. Also it was found that as traffic volume increases and pedestrian volume decreases, the benefit increases. In this study, the criteria for installation of pushbutton on the crosswalks of mid-block are developed through the sensitivity analysis and benefit/cost analysis. The results of this study may be used as a criteria for expansion of pushbutton system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.1-2
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• 2011

Hybrid rockets have lately attracted attention as a strong candidate of small, low cost, safe and reliable launch vehicles. A significant topic is that the first commercially sponsored space ship, SpaceShipOne vehicle chose a hybrid rocket. The main factors for the choice were safety of operation, system cost, quick turnaround, and thrust termination. In Japan, five universities including Hokkaido University and three private companies organized "Hybrid Rocket Research Group" from 1998 to 2002. Their main purpose was to downsize the cost and scale of rocket experiments. In 2002, UNISEC (University Space Engineering Consortium) and HASTIC (Hokkaido Aerospace Science and Technology Incubation Center) took over the educational and R&D rocket activities respectively and the research group dissolved. In 2008, JAXA/ISAS and eleven universities formed "Hybrid Rocket Research Working Group" as a subcommittee of the Steering Committee for Space Engineering in ISAS. Their goal is to demonstrate technical feasibility of lowcost and high frequency launches of nano/micro satellites into sun-synchronous orbits. Hybrid rockets use a combination of solid and liquid propellants. Usually the fuel is in a solid phase. A serious problem of hybrid rockets is the low regression rate of the solid fuel. In single port hybrids the low regression rate below 1 mm/s causes large L/D exceeding a hundred and small fuel loading ratio falling below 0.3. Multi-port hybrids are a typical solution to solve this problem. However, this solution is not the mainstream in Japan. Another approach is to use high regression rate fuels. For example, a fuel regression rate of 4 mm/s decreases L/D to around 10 and increases the loading ratio to around 0.75. Liquefying fuels such as paraffins are strong candidates for high regression fuels and subject of active research in Japan too. Nakagawa et al. in Tokai University employed EVA (Ethylene Vinyl Acetate) to modify viscosity of paraffin based fuels and investigated the effect of viscosity on regression rates. Wada et al. in Akita University employed LTP (Low melting ThermoPlastic) as another candidate of liquefying fuels and demonstrated high regression rates comparable to paraffin fuels. Hori et al. in JAXA/ISAS employed glycidylazide-poly(ethylene glycol) (GAP-PEG) copolymers as high regression rate fuels and modified the combustion characteristics by changing the PEG mixing ratio. Regression rate improvement by changing internal ballistics is another stream of research. The author proposed a new fuel configuration named "CAMUI" in 1998. CAMUI comes from an abbreviation of "cascaded multistage impinging-jet" meaning the distinctive flow field. A CAMUI type fuel grain consists of several cylindrical fuel blocks with two ports in axial direction. The port alignment shifts 90 degrees with each other to make jets out of ports impinge on the upstream end face of the downstream fuel block, resulting in intense heat transfer to the fuel. Yuasa et al. in Tokyo Metropolitan University employed swirling injection method and improved regression rates more than three times higher. However, regression rate distribution along the axis is not uniform due to the decay of the swirl strength. Aso et al. in Kyushu University employed multi-swirl injection to solve this problem. Combinations of swirling injection and paraffin based fuel have been tried and some results show very high regression rates exceeding ten times of conventional one. High fuel regression rates by new fuel, new internal ballistics, or combination of them require faster fuel-oxidizer mixing to maintain combustion efficiency. Nakagawa et al. succeeded to improve combustion efficiency of a paraffin-based fuel from 77% to 96% by a baffle plate. Another effective approach some researchers are trying is to use an aft-chamber to increase residence time. Better understanding of the new flow fields is necessary to reveal basic mechanisms of regression enhancement. Yuasa et al. visualized the combustion field in a swirling injection type motor. Nakagawa et al. observed boundary layer combustion of wax-based fuels. To understand detailed flow structures in swirling flow type hybrids, Sawada et al. (Tohoku Univ.), Teramoto et al. (Univ. of Tokyo), Shimada et al. (ISAS), and Tsuboi et al. (Kyushu Inst. Tech.) are trying to simulate the flow field numerically. Main challenges are turbulent reaction, stiffness due to low Mach number flow, fuel regression model, and other non-steady phenomena. Oshima et al. in Hokkaido University simulated CAMUI type flow fields and discussed correspondence relation between regression distribution of a burning surface and the vortex structure over the surface.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.169-197
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• 2018

The purpose of this study is to present a reasonable and concrete standard for the Korean aviation insurance compulsory subscription system. Through this, we aim to improve the current revision of laws and regulations, and ultimately create an environment in which the safety and property of the Korean people who use aircraft with appropriate aviation insurance can be secured. In particular, by reviewing the aviation business law and its new laws and regulations enacted in 2017, the legislative improvement direction of aviation insurance will be proposed. In order to maintain the continuous growth of the air transportation industry and to make amicable compensation for the victims, considering the characteristics of the total accident, instantness, and giganticness of air accidents in which a lot of people and property are lost in the event of an accident, adequate insurance coverage is essential. In this respect, the compulsory insurance to amend the principle of freedom of contract, which is the great principle of the modern judicial system, will be persuasive. However, in comparison with foreign legislation, the legal provisions on Korea's obligation to comply with aviation insurance need to be revised around the following issues: First, it is reasonable to enforce the regulation of the mandatory aviation insurance by legislation from the Congress not by administrative regulations. Because it will force the monetary obligations of the individual such as common air carriers. Second, our law regulations respond to various kinds of air damages by using the phrase "limit of liability stipulated in international conventions". However, as we have seen in the text, the range of compensation are various according to the use of legal instruments in international conventions such as the Montreal Convention, which governs the compensation of passengers for damages to passengers today. Third, in countries with narrow territories, such as Korea, there are big differences in flying time and insurable risk between domestic and international transportation. Therefore, it is necessary to divide domestic transportation and international transportation even in the obligation to join the insurance. This dual discipline has the advantage for rookies in air carrier market who mainly start their business from domestic service. Fourth, according to Korean law, the regulations of automobile loss insurance is applicable to the aviation mandatory insurance of unmanned aerial vehicle accident which is lack of persuasion. In the future, it will be appropriate to discipline insurance for unmanned aerial vehicles with unlimited potential for development from a long-term perspective.