• Journal of the Korea Convergence Society
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• v.4 no.1
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• pp.27-31
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• 2013

The fast-paced development in the field of wireless charger based on M2M, which is available anytime and anywhere, is being underway in accordance with the development of IT technology. Wireless charger technology in M2M has various security threats because it is based on wireless network. The purpose of this paper is to examine the threats of authentication and payment attacks based on wireless network attacks, and to propose the response technique that fit the situation of the wireless charger service by modifying the existing detecting authentication and payment through wireless charger.

• Journal of Biosystems Engineering
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• v.19 no.4
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• pp.301-310
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• 1994

The feasibility of using ultrasonic-wave doppler sensors for a measurement of the actual ground speed of agricultural machines was investigated. The actual ground speed is estimated from the doppler shift frequencies of the two ultrasonic-waves transmitted to and received from a moving object. A prototype of the speed-measurement system was designed and constructed for the performance test. The measurement system showed a good performance with a flat surface at speeds lower than 3m/s. However, it was failed to receive the reflected signals from the rough and irregular soil surfaces. Further researches to solve this problem and to improve its performance are now underway.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.353-358
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• 1999

New emerging post weaning multisystemic wasting syndrome (PMWS) threatening swine industry worldwide and investigation of the etiological agent is underway. The porcine circovirus (PCV) consistently identified from PMWS pigs and research result indicate that there is strong relationship between PCV and PMWS. Fauns with PMWS submitted pigs suffered from various PMWS typical signs and necropsy finding showed lymph node anomalies. The PCV DNA was amplified from inguinal lymph node collected from pigs with PMWS. PCV specific primers were successfully amplified PCV DNAs and were able to differentiate PCV type I and II. We have identified noble PCV virus with genetic variation. The virus showed insertion of the nucleic acid at the 5' of the genome but did not have PCR product with primer set corresponding to PCV type II virus.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.89-94
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• 2003

Recently, the study to reduce and recycle industrial waste is underway vigorously in the various fields of industry according to the conservation of environment and resources. In construction work, the disposal problem of its waste and environmental disruption have already been serious all over the world. However the recycle of waste concrete is still at an early stage, recycled aggregate from waste concrete have only used those as subsidiary road fillers. The research institute and the company make the study that it is about the properties of recycled aggregate and those structural capacity since 1990. Through the experimentation last year, we know that strength and fluidity of recycle cement are inferior to normal cement, and admixing aggregate powder deteriorates its strength. The purpose of this study is to search for appropriate heating time and to improve performance of the recycle cement while heating hardened cement which is crushed, we investigate separating aggregate from hardened cement by preheating and improvement of strength and fluidity inrecycle cement which contains admixture.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.195-196
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• 2018

The Research is underway to utilize heavyweight concrete for various applications. One of them is to use heavy concrete as a marine concrete such as a breakwater to resist wave. Marine concrete is often complex in shape and requires high fluidity. When the heavyweight concrete is high fluidity, there is a high risk of segregation due to the high density of the coarse aggregate. Therefore, we evaluate the fluidity of heavyweight concrete using heavy fine aggregate. As a result of the fluidity evaluation of the heavyweight concrete, the fluidity of the heavy fine aggregate was similar to that of ordinary concrete. Therefore, it is considered that the use of heavy fine aggregate in the development of high fluidity heavyweight concrete will be one of the methods.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1012-1013
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• 2006

Marine technology must advance to meet the needs of a wealthier and more demanding public while at the same time provide greater environmental protection. Pollution noise and vibration is the specific issue being discussed in this paper Noise is of course due to vibration from high speed engines driving generators, entilators, winch and other gear, while underwater noise pollution results from the propellers and the resistance produced by the hull of the ship moving through the water. Vibration is also a factor in potential damage to sensitive electronic gear and metal fatigue. The issue of noise pollution does not cease when a vessel enters her berth and the main engines shut down. There is still the matter of ventilation and other mechanical factors at work to maintain a comfortable, efficient environment. We measured the noise level and vibration displacement in the training ship A-Ra at underway and Berth. The authors analyzed the frequency of noise and maximum vibration displacement in the position.

• International Journal of Railway
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• v.7 no.1
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• pp.8-15
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• 2014

Recently, in the total railroad construction field, concrete slab tracks have been adapted in place of ballast tracks. Because ballast tracks need frequent maintenance and are difficult to handle due to increasing maintenance costs, eventually concrete slab tracks were selected as an alternative. However, owing to the hydration heat reactions and temperature-affected shrinkage of the concrete, a variety of studies to solve maintenance problems related to concrete slab tracks are underway. This study analyzed characteristics of TQI values evaluating track irregularity, investigated the relationship between crack progress and TQI, and then evaluated the correlation between the two values. Through our analysis, we found that there is a need to supplement the problems of the current method and develop a track evaluation index which takes cracking into account. We also concluded that TQI is the main decision-making tool in track maintenance.

• Electronics and Telecommunications Trends
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• v.33 no.5
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• pp.33-41
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• 2018

The paradigm of mobile communication technology has changed from an increase in transmission capacity to service-based technologies satisfying various types of service requirements. One of the new paradigms is a service that provides users with a QoE (Quality Of Experience (QoE), at anytime and anywhere. 5G defines various technologies such as dense network structures and beam selection for increasing the transmission capacity and ensuring the quality of experience so as to satisfy this requirement, and related research is underway. In this paper, we describe the definition of a 5G small cell and 5G network structure as well as research trends of standardization and related technologies for constructing optimal solutions for mobile users in dense networks based on small cells.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.453-456
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• 2008

This study is underway to develop a prediction model for formwork pressure exerted by self-compacting concrete(SCC). Three major mechanisms related to formwork evolution over time were found, and mathematical modelling of each mechanism was made. A calculation method for real formwork pressure by using the mathematical formulae was also established. To verify predictive capability of the prediction model, a parametric study on parameters used in the model was performed. It was confirmed that the proposed model include the essential parameters that can simulate the real formwork pressure evolution over time.

• Korean Journal of Social Welfare
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• v.38
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• pp.100-125
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• 1999

As economic crisis has deepened mass unemployment and widespread destitution since the end of 1997, the Korean society is now underway of social disorganisation. It is thus widely accepted that National Basic Livelihood Programme, which reformed the existing public assistance programme, is urgently needed to relieve low-income families from extreme poverty. It is in this regard that this paper purports to review the debates on, and to suggest the feasible schemes for the National Basic Livelihood Programme. For this purpose, chapter two critically reviews government's comprehensive counter-measures against mass unemployment, and chapter three examines main points of the National Basic Livelihood Act. Chapter four compares "programme-centrad approach" and "basic living approach", and duly suggests feasible schemes for the National Basic Livelihood Programme.