• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.807-812
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• 2020

In order to prevent the national wide spread of the COVID-19 virus, the government enforces to use an electronic access registration system for public facilities to effectively track and manage the spread. Initially, there was a lot of hassle to write a directory, but recently a system for creating an electronic access list using QR codes, what is called KI-Pass, is mainly used. However, the procedure for generating a QR code is somewhat cumbersome. In this paper, we propose a new electronic access registration system that does not require QR code. This system effectively controls the suspicious visitor by using a mask wearing discriminator which has been implemented using deep learning technology, and a non-contact thermometer package. In addition, by linking the beacon, a short-range wireless communication technology, and the visitor's smartphone application, basic information of the facility visitor is automatically registered to KDCA through the server. On the other hand, the user access information registered in the server is encrypted and stored, and is automatically destroyed after up to 4 weeks. This system is expected to be very effective in preventing the spread of other new infectious diseases as well as responding to the coronavirus which is recording a high spread worldwide.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.38-47
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• 2009

This paper aims to evaluate the freeway traffic management Strategy based on exTMS according to traffic situation of freeway. As freeway user's demands increase, we thus need future-oriented and optimized traffic management. So, through improving the existing system and introducing the advanced system, these systems evaluate for not only preparing the application in real world but also preliminary feasibility. To evaluate effects of the traffic management based on exTMS, in this study, shoulder LCS, advanced VMS(assumption in it is improving next-generation system which it can be offering diverse dynamic traffic information), Ramp-metering system are applicated in simulation. In addition, this study evaluates the effect when all proposed systems are applicated, and compare the individual effect of when independent system is applicated, through considering about traffic condition of V/C=0.5, V/C=0.8, V/C=1.2. The study results show that all assumed cases, the travel speed were improved according to the increasing V/C. Furthermore, the results of evaluated the individual system show that the shoulder LCS was found to be the largest effect, and the effect of VMS(detour rate is 11%) is larger than the other cases.

• Korean Journal of Childcare and Education
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• v.7 no.2
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• pp.181-203
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• 2011

The purposes of this study were to examine the perception of directors and child care providers regarding the Seoul-type Child Care Accreditation and its operating system. The objects were 309 directors and child care providers at accredited Seoul-type child care centers. The collected data was analyzed using frequency, percentiles, and ${\chi}^2$. The results are as follows: First, the majority of directors and child care providers perceived 'the preparation for effective quality control of child-care service' as the primary purpose of the Seoul-type Child Care Accreditation. Many of them responded that the child care centers meeting the purpose of accreditation would be 'private' and 'home-based' ones. Seoul-type Child Care Accreditation was easier to pass compared to National Child Care Accreditation. The directors and child care providers perceived that the accreditation will narrow the gap between public and private child care centers. Second, in operating customized child-care service, most directors preferred 'submits only the same plan as that of a designated one', but most child care providers preferred 'assessment after providing customized child-care'. For the reliable child-care service and accounting management system, both subject groups showed general satisfaction with 'current system'. Third, both subject groups responded that 'overtime pay for child care providers' and 'government's consistent child-care policy' were what they desire most to improve Seoul-type Child Care Accreditation.

• Journal of The Korean Astronomical Society
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• v.36 no.3
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• pp.81-87
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• 2003

It is suggested that a flying-by star in a hot accretion disk may cool the hot accretion disk by the Comptonization of the stellar emission. Such a stellar cooling can be observed in the radio frequency regime since synchrotron luminosity depends strongly on the electron temperature of the accretion flow. If a bright star orbiting around the supermassive black hole cools the hot disk, one should expect a quasi-periodic modulation in radio, or even possible an anti-correlation of luminosities in radio and X-rays. Recently, the unprecedentedly accurate infrared imaging of the Sagittarius A$\ast$ for about ten years enables us to resolve stars around it and thus determine orbital parameters of the currently closest star S2. We explore the possibility of using such kind of observation to distinguish two quite different physical models for the central engine of the Sagittarius A$\ast$, that is, a hot accretion disk model and a jet model. We have attempted to estimate the observables using the observed parameters of the star S2. The relative difference in the electron temperature is a few parts of a thousand at the epoch when the star S2 is near at the pericenter. The relative radio luminosity difference with and without the stellar cooling is also small of order $10^{-4}$, particularly even when the star S2 is near at the pericenter. On the basis of our findings we tentatively conclude that even the currently closest pass of the star S2 is insufficiently close enough to meaningfully constrain the nature of the Sagittarius A$\ast$ and distinguish two competing models. This implies that even though Bower et al. (2002)have found no periodic radio flux variations in their data set from 1981 to 1998, which is naturally expected from the presence of a hot disk, a hot disk model cannot be conclusively ruled out. This is simply because the energy bands they have studied are too high to observe the effect of the star S2 even if it indeed interacts with the hot disk. In other words, even if there is a hot accretion disk the star like S2 has imprints in the frequency range at v $\le$ 100 MHz.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.183-186
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• 2000

본 논문에서는 인식이 진행되는 동안 탐색 공간을 효과적으로 줄임으로써 음성인식의 고속화를 달성할 수 있는 새로운 프레임 단위 적응 프루닝 알고리즘을 제안하고 실험을 통하여 그 유효성을 확인하였다. 이것은 앞 프레임과 뒤 프레임 사이의 최대확률은 높은 상관성을 가지므로 프루닝 문턱치를 앞 프레임의 최대 확률로부터 효과적으로 구할 수 있다는 사실에 근거를 두고있다. 이 방법에서는 앞 프레임의 최대 우도 확률과 후보 확률들의 조합으로 현재 프레임의 프루닝 문턱치를 갱신함으로써 현재 프레임의 문턱치를 인식 과정 중에 얻을 수 있기 때문에, 인식 태스크가 바뀌어도 문턱치를 구하기 위한 사전 실험을 수행할 필요가 없게 된다. 또한, 프레임 단위로 적응적으로 얻어진 문턱치는 다른 환경 하에서도 인식 속도의 향상을 가져올 수 있게 된다. 제안된 알고리즘의 유효성을 확인하여 위하여 한국어 주소 인식 시스템에 적용하였다. 본 시스템은 48개의 유사음소단위(PLUs)를 인식의 기본단위로 하고, 적응알고리즘으로는 최대사후확률추정법((MAP: Maximum A Posteriori Probability Estimation)을, 인식 알고리즘으로는 OPDP(One Pass Dynamic Programming)법을 이용하였다 남성화자 3인이 25개의 연결 주소명을 대상으로 인식 실험을 수행한 결과, 제안된 프레임단위 적응프루닝 문턱치를 적용한 경우를 기존의 고정 프루닝 문턱치와 가변 프루닝 문턱치를 적용한 경우와 비교하였을 때 인식률의 변화 없이 탐색공간이 상대적으로 각각 $14.4\%와 $9.14\%가 감소되어 제안된 프레임 단위 적응 프루닝 알고리즘의 유효성을 확인할 수 있었다. 시,공간적 분포 특성이 구체적으로 규명되면 보다 정확한 음장변화 추정이 이뤄져야 할 것으로 보인다. 또한 내부파와 음파의 상대적인 진행 방향에 따라 음장변화가 크게 다를 것이 예상되므로 이를 규명하기 위해서는 궁극적으로 3차원적인 음장분포 연구가 필요하다. 음향센서를 해저면에 매설할 경우 수충의 수온변화와 센서 주변의 수온변화 사이에는 어느 정도의 시간지연이 존재하게 되므로 이에 대한 영향을 규명하는 것도 센서의 성능예측을 위해서 필요하리라 사료된다.가지는 심부 가스의 개발 성공률을 증가시키기 위하여 심부 가스가 존재하는 지역의 지질학적 부존 환경 및 조성상의 특성과 생산시 소요되는 생산비용을 심도에 따라 분석하고 생산에 수반되는 기술적 문제점들을 정리하였으며 마지막으로 향후 요구되는 연구 분야들을 제시하였다. 또한 참고로 현재 심부 가스의 경우 미국이 연구 개발 측면에서 가장 활발한 활동을 전개하고 있으며 그 결과 다수의 신뢰성 있는 자료들을 확보하고 있으므로 본 논문은 USGS와 Gas Research Institute(GRI)에서 제시한 자료에 근거하였다.ऀĀ耀Ā삱?⨀؀Ā Ā?⨀ጀĀ耀Ā?돀ꢘ?⨀硩?⨀ႎ?⨀?⨀넆돐쁖잖⨀쁖잖⨀／ࠐ?⨀焆덐瀆倆Āⶇ퍟ⶇ퍟ĀĀĀĀ磀鲕좗?⨀肤?⨀⁅Ⴅ?⨀쀃잖⨀䣙熸ጁ↏?⨀

• The Journal of the Acoustical Society of Korea
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• v.39 no.4
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• pp.303-317
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• 2020

Extracorporeal Shock Wave Therapy (ESWT) is an innovative treatment in chronic musculoskeletal pain management and cardiovascular diseases. In this study, we surveyed the acoustic shock wave outputs from the domestically used focal type ESWT devices. The survey data were collected through 30 technical documents registered to the Ministry of Food and Drug Safety (MFDS), Rep. Korea. The results show that the focusing geometry varies largely, 5 mm to 65 mm in the focal length, 3 mm to 30 mm in focal width, and 4 mm to 108 mm in focal depth. The maximum positive pressure (P+) ranges from 7 MPa to 280 MPa, the focal Energy Flux Density (EFD) from 0.0035 mJ/㎟ to 35 mJ/㎟, and the energy per pulse (E) from 0.737 mJ to 80.86 mJ. All domestic PE-type (five) and one EM-type domestic devices included in the analysis of the correlation between P+ and EFD are shown to be far beyond the usual ranges and do not comply with expected correlation so that the reliability of their data was suspected. For the suspected, post-performance tests are required by a recognized testing agency. MFDS guidelines need to be revised so that the pass criteria for the shock wave acoustic outputs can be based on the clinical tests for indications.

• Journal of Adhesion and Interface
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• v.19 no.3
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• pp.113-117
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• 2018

Boron carbide is lower in hardness than diamond or boron nitride but has a hardness of more than 30 GPa and is used for manufacturing tank armors and ammo shells due to its high hardness. It is also used as a neutron absorber due to its ability to absorb neutrons, which is increasing its use in nuclear power projects. Neutrons have no interaction with electrons and are known to pass through the material without interactions. Along with boron carbide, the atoms with high interaction with neutrons are hydrogen, and high hydrogen concentration polyesters and epoxy polymers including boron are used as materials for manufacturing products for nuclear power generation waste. In this paper, the surface of boron carbide is treated with iron oxide and tungsten to improve interaction between modified boron carbide and epoxy polymer. XRD and XPS were used to confirm that iron oxide and tungsten are well attached on the surface of boron carbide, respectively. The mechanical strength of the surface treated boron carbide was measured by a universal testing machine (UTM) and the dynamic characteristics of the cured product were observed by using a dynamic analyzer (DMA).

• Land and Housing Review
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• v.1 no.1
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• pp.35-42
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• 2010

Most of the dredged sand generated from the sewage pipe maintenance project and the government's four-river project are disposed depending on abandonment and filling-up. This is caused by the lack of related recycling technology using dredged sand appropriately and high absorption rate and micro-particles of dredged sand producted from existing sand production system. Thus, this study carried out a quality assessment for the dredged sand produced through the optimum washing and sorting system supplementing problems of existing dredged sand production system as a part of research to examine performance of removing micro-particles and foreign substances. As a result of the assessment, the dredged sand produced through the cleaning and sorting system showed a wide quality improvement effect in absorption rate, 0.08 mm sieve pass amount, clay lump volume and organic impurity content, and it turned out to satisfy both the quality standards of this study, KS F 2573(recycled aggregate for concrete) and KS F 2526(aggregate for concrete) so it could be confirmed that it would be able to be used as an aggregate for concrete in the future.

• International Journal of Railway
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• v.2 no.3
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• pp.124-126
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• 2009

Energy savings can be achieved with optimum energy consumptions, brake energy regeneration, efficient energy storage (onboard, line side), and primarily with light weight vehicles. Over the last few years, the rolling stock industry has experienced a marked increase in eco-awareness and needs for lower life cycle energy consumption costs. For rolling stock vehicle designers and engineers, weight has always been a critical design parameter. It is often specified directly or indirectly as contractual requirements. These requirements are usually expressed in terms of specified axle load limits, braking deceleration levels and/or demands for optimum energy consumptions. The contractual requirements for lower weights are becoming increasingly more stringent. Light weight vehicles with optimized strength to weight ratios are achievable through proven design processes. The primary driving processes consist of: $\bullet$ material selection to best contribute to the intended functionality and performance $\bullet$ design and design optimization to secure the intended functionality and performance $\bullet$ weight control processes to deliver the intended functionality and performance Aluminium has become the material of choice for modern light weight bodyshells. Steel sub-structures and in particular high strength steels are also used where high strength - high elongation characteristics out way the use of aluminium. With the improved characteristics and responses of composites against tire and smoke, small and large composite materials made components are also found in greater quantities in today's railway vehicles. Full scale hybrid composite rolling stock vehicles are being developed and tested. While an "overdesigned" bodyshell may be deemed as acceptable from a structural point of view, it can, in reality, be a weight saving missed opportunity. The conventional pass/fail structural criteria and existing passenger payload definitions promote conservative designs but they do not necessarily imply optimum lightweight designs. The weight to strength design optimization should be a fundamental design driving factor rather than a feeble post design activity. It should be more than a belated attempt to mitigate against contractual weight penalties. The weight control process must be rigorous, responsible, with achievable goals and above all must be integral to the design process. It should not be a mere tabulation of weights for the sole-purpose of predicting the axle loads and wheel balances compliance. The present paper explores and discusses the topics quoted above with a view to strengthen the recommendations and needs for the weight optimization by design approach as a pro-active design activity for the rolling stock industry at large.

• The Korean Journal of Physiology
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• v.30 no.1
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• pp.105-116
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• 1996

Rendering the brain ischemic would evoke the cerebral ischemic reflex which is characterized by an arterial pressor response, apnea and bradycardia. Since the rostral ventrolateral medulla (RVLM) is known to play a key role in the maintenance of normal cardiopulmonary activity, during the cerebral ischemic reflex some cardiac related cells should be excited and respiration related cells inhibited. In this context, the responses of RVLM neurons to systemie and focal hypoxia were analyzed in the present study. Twenty-five adult cats of either sex were anesthetized with ${\alpha}-chloralose$ and the single neuronal activities were identified from RVLM area. For the induction of focal hypoxia in the recording site, sodium cyanide was applied iontophoretically and for systemic hypoxia the animal was ventilated with nitrogen gas for a twenty-second period. Cellular activities were analyzed in terms of their discharge pattern and responses to the hypoxia by using post-stimulus time and single-pass time histograms. Of eighteen cardiac related cells recorded from the RVLM area, twelve cells were excited by iontophoresed sodium cyanide and of twenty-five respiration related cells, fourteen cells were excited by iontophoresed sodium cyanide. Remaining cells were either inhibited or unaffected. Eight of fifteen cells tested with iontophoresed sodium lactate were excited and remaining seven cells were inhibited. Systemic hypoxia induced by nitrogen gas inhalation elevated the arterial blood pressure, but excited, inhibited or unaffected the single neuronal activities. Some cells showed initial excitation followed by inhibition during the systemic hypoxia. Bilateral vagotomy resulted in a decrease of arterial pressor response to the systemic hypoxia, and a slight decrease in the rhythmicity related to cardiac and/or respiratory rhythms. The single neuronal responses to either systemic or focal hypoxia were not affected qualitatively by vagotomy. From the above results, it was concluded that the majority of the cardiac- and respiration- related neurons in the rostral ventrolateral medulla be excited by hypoxia, not through the mediation of peripheral chemoreceptors, and along with the remaining inhibited cells, all these cells be involved in the mediation of cerebral ischemic reflex.