• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1148-1157
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• 2022

The maritime safety act defines a large vessel as a vessel of at least 200m in length overall. Since this standard was introduced in 1986, it has not been revised even though the marine traf ic environment has changed significantly. The length overall of 200m is equivalent to the handymax class for a dry bulker; therefore, classifying this as a modern large vessel size is difficult. Meanwhile, according to the maritime safety act, the specific sea area for traffic safety is established where large vessels frequently pass. Accordingly, by reviewing maritime-related laws, this study confirmed that standards for vessels larger than 200m in length overall were already introduced. Furthermore, by examining the statistics of vessels entering Korean ports, the existence of sea areas with a lot of traffic by large vessels, except the current 5 specific areas, was confirmed. Therefore, the following were suggested: the deletion of the term large vessel, a raise in the standard for length of a vessel related to a specific sea area in the maritime safety act.

• Journal of Animal Science and Technology
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• v.55 no.1
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• pp.1-6
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• 2013

This study was aimed to solve the problems of current national genetic evaluation systems in Korea and its development to pass the verification processes as required by International Bull Evaluation Service (Interbull). This will enable Korea to participate in international genetic evaluation program. A total of 1,416,589 test-day milk records with calving dates used in this study were collected by National Agricultural Cooperative Federation from 2001 to 2009. Parity was limited up to fifth calving and milk production records were adjusted to cumulative 305 day lactation. The pedigree consisted of 2,279,741 animals where 2,467 bulls had 535,409 parents. A newly developed multiple trait model was used in calculation of breeding values for milk yield, milk fat, and protein yield. Data were edited with SAS (version 9.2) and R programs, and genetic parameters were estimated using VCE 6.0. Results showed a continuous increase in genetic potentials, in general, and no remarkable differences were found between performances by parity. Except fat yield, potentials in milk yield and protein yield were well calculated. We found an increased number of daughters per each top ranked 1,000 bulls in recent years of calf births compared to the cases of previous evaluations. Of the bulls ranked top 100 by our new models (multiple-trait models) we found that increased numbers of bulls were included. Of twenty eight bulls born in 2006, twenty bulls born in 2007 and eight bulls born in 2008 that were listed by new models, only 23, 12, and 2 bulls born in respective years were represented on top 100 by old single-trait models. Re-ranking of the daughters or sires by multiple-trait models suggest that this new multiple trait approach should be used for dairy cattle genetic evaluation and seed-stock selection in the future to increase the accuracy of multiple trait selection. Breeding values for these traits should also be calculated by new method for international genetic evaluation.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.11
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• pp.152-165
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• 1998

The contour coding usually occupies the biggest part in the encoded bitstream, which causes the bottleneck problem of a region-based coding scheme. In this paper, new adaptive contour coding technique is proposed for the segmentation-based image coding. By adaptive contour coding considering contrast of neighbor regions in the proposed method, the overall bitrate can be significantly reduced without loss of the subjective image quality. After segmentation using watershed algorithm to the image, the contour segments are classified according to the contrast of the adjacent regions. Then, the contour segments between classified low contrast regions are highly compressed using morphological low pass filtering. The needed bits for encoding the contour information is reduced without loss of subjective image quality in the experiment.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.99-106
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• 2014

In this paper, we analyze weaknesses of the biometrics-based user authentication scheme proposed by An. The result of analysis An's authentication scheme by the login success scenario proposed in this paper, if the attacker successes to get user's random number, he/she can pass user authentication phase of the legal server. Also the biometrics guessing scenario proposed in this paper shows the legal user's the biometric information is revealed in lost smart card. Since An's authentication scheme submit user ID and biometrics in plain text to the server, it is very vulnerable to inner attack and it is not provide the user anonymity to the server as well as the one to the third by user ID in plain text. Besides An's authentication scheme is contextual error too, due to this, it has weakness and so on that it did not check the validity of the smart card holder.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.883-889
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• 2006

In this paper, parasitic resonance modes generated in a conductor backed coplanar wave guide(CBCPW) and stripline band pass filter(BPF) and the oscillation phenomena of a 40 GHz power amplifier module(PAM) are analyzed and several methods to suppress them are presented for low-temperature co-fired ceramic(LTCC) based millimeter-wave RF System-in-Package(SiP) applications. Parasitic rectangular wave guide(RWG) modes of the CBCPW structure are completely suppressed in the operation frequency band by decreasing the distance between its vias and by increasing the mode frequency. In the stripline structure, RWG resonance modes are clearly eliminated by removing some vias facing each other and by placing them diagonally. In the case of the 40 GHz PAM, in order to reduce a cross talk due to radiation that is generated from interconnection discontinuities, high isolation structures such as embedded DC bas lines and CPW signal lines are used and then the oscillated PAM is improved.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.483-496
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• 2018

Purpose: This paper proposes a quality strategy based on the evolution of technology in the age of the 4th Industrial Revolution. Methods: We examine the theory of past quality activities and the changes in quality paradigm, and analyze key words for the technologies and key issues of the 4th Industrial Revolution. Based on existing quality management, we find a quality strategy that should be pursued during the 4th Industrial Revolution. Results: Quality has been recognized as an essential component of corporate competitiveness. The paradigm of quality has also changed with the pass of time and industry development. From this viewpoint, the following eight quality strategies are proposed for the development of the technology of the 4th Industrial Revolution period, such as Market-to-customer fusion quality, symbiotic quality, big data quality, technical accuracy and zero-defect quality, facility predictability quality, software quality, process flexibility quality, and information protection stability and security quality. Conclusion: Quality for customer satisfaction is still important nowadays. However, in the 4th Industrial Revolution era, where various business models and methods of manufacturing are expected, the big data utilization, software quality, and the reliability and security of information protection to support it are important.

• Resources Recycling
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• v.19 no.4
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• pp.3-12
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• 2010

Countries which have a lot of metal resources are weaponizing metal resources such as supply limitation, high price sale. It's necessary for us to establish the countermeasure for recycling of used metal resources on a government basis. Ministry of Environment has established and announced the project for finding and reuse the hidden metal resources as pan-government department pass the Cabinet meeting at September 22, 2009. This countermeasure, 10 years project, is classified into 2 steps. Aim of this project is advance of the recycling technology and industry, achievement of recycling rate, 75%, improvement in adverse balance of trade, 1.25 billion US$.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.10-15
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• 1999

We have studied a method to design and fabricate the Intermediate Frequency(IF) band pass filter with low shape factor which is used for CDMA base station on the 35°Y-cut X-propagation Quartz substrate. In order to fabricate a device of the low shape factor for the IF SAW filter on this substrate, we employed apodization weighted type interdigital transducer(IDT) as an input and withdrawal weighted type IDT as an output by using impulse modelling method. Also, using the Kaiser-Bessel window function, we have adopted 2200pairs and 1000pairs of input and oueut IDT respectively to minimize the effect of ripple. Furthermore, the width and the space of IDT finger are 3.6 ㎛ and 3.5 ㎛ respectively. Thus, we can have optimal results when the IDT thickness is 6000Å in consideration of the ratio of SAW's wavelength while it's aperture is 2mm for impedance matching. The fabricated SAW filter for CDMA had the property of almost 115.2MHz of a center frequency, less then 1.27MHz of bandwidth, less than 1.3 of shape factor, - l5dB of out band attenuation insertion loss and -45dB of rejection band.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1479-1485
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• 2010

In recent times, due to wire drawing of high carbon steel at a high speed to ensure a high productivity and high strength, axial residual stress are generated because of rapid increase in surface temperature. In the process, the temperatures of the wires increased because of the deformation of the wires and the friction between the die and wire. In particular, in the case of the wire drawing at a high speed, friction leads to a large temperature gradient so that considerable axial residual stress is generated on the surface. In this study, the relationship between axial residual stress and increase in the surface temperature was investigated, and a prediction model of uniform temperature was proposed. Then, a prediction model for residual stress was developed. The proposed model was verified by measuring the residual stress by X-ray diffraction on drawn wires.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1330-1338
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• 2011

Social activities of the elderly have been increasing as our society progresses toward an aging society. As their activities increase, so does the occurrence of falls that could lead to fractures. Falls are serious health hazards to the elderly. Therefore, development of a device that can detect fall accidents and prevent fracture is essential. In this study, we developed a portable fall detection system for the fracture prevention system of the elderly. The device is intended to detect a fall and activate a second device such as an air bag deployment system that can prevent fracture. The fall detection device contains a 3-axis acceleration sensor and two 2-axis tilt sensors. We measured acceleration and tilt angle of body during fall and activities of daily(ADL) living using the fall detection device that is attached on the subjects'. Moving mattress which is actuated by a pneumatic system was used in fall experiments and it could provide forced falls. Sensor data during fall and ADL were sent to computer and filtered with low-pass filter. The developed fall detection device was successful in detecting a fall about 0.1 second before a severe impact to occur and detecting the direction of the fall to provide enough time and information for the fracture preventive device to be activated. The fall detection device was also able to differentiate fall from ADL such as walking, sitting down, standing up, lying down, and running.