• Journal of the Korean Society for Nondestructive Testing
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• v.37 no.1
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• pp.37-43
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• 2017

Ultrasonic transducers with high resolution and resonant frequency are required to detect small defects (less than hundreds of ${\mu}m$) by ultrasonic testing. The resonance frequency and resolution of an ultrasonic transducer are closely related to the thickness of piezo-electric materials, backing materials, and the electric impedance matching technique. Among these factors, electrical impedance matching plays an important role because it can reduce the loss and reflection of ultrasonic energy differences in electrical impedance between an ultrasonic transducer and an ultrasonic defects detecting system. An LC matching circuit is the most frequently used electric matching method. It is necessary for the electrical impedance of an ultrasonic transducer to correspond to approximately $50{\Omega}$ to compensate the difference in electrical impedance between both connections. In this study, a 15 MHz immersion ultrasonic transducer was fabricated and an LC electrical impedance circuit was applied to that for having broad-band frequency characteristic.

• Journal of Digital Contents Society
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• v.19 no.1
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• pp.213-220
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• 2018

Face morphing, one of the most powerful image processing techniques that are often used in image processing and computer graphic fields, as it is a technique to change the image progressively and naturally from the original image to the target image. In this paper, we propose a method to generate Delaunay triangles using the facial landmark vertices generated by the Dlib face landmark detector and to implement morphing through warping and cross dissolving of Delaunay triangles between the original image and the target image. In this paper, we generate vertex points for face not manually but automatically, which is the major feature of the face such as eye, eyebrow, nose, and mouth, and is used to generate Delaunay triangles automatically which is the main characteristic of our face morphing method. Simulations show that we can add vertices manually and get more natural morphing results.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.51-59
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• 2010

Apartment complex, buildings, markets and department stores have inner parking lots which can accept many cars but drivers waste lots of times to find the empty parking spaces in crowding parking lots. In this paper, we proposed the inner parking information support system based on microprocessor which can decrease roaming times to find vacant parking spot in confusing parking lots through notice monitor and provide SMS to make it easy to find parked place. Proposed system consist with RFID system for detecting access of cars, microprocessor system for processing data of checking existence of cars on parking spots and communicating with server, and server system which processes information of cars' in and out, guides empty parking spots and parked location to drivers. Suggested system is realized by handmade model parking lot size of 8 cars, and we confirmed practicality by providing information using parking notice monitor and single message service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.475-478
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• 2014

This paper proposed the position tracking and recognition method of workers and cars in construction field. The reason why the position of workers and cars has to be tracked is to prevent the safety accident, emergency rescue, and theft of building materials by unauthorized people and car, etc. To realize the tracking, it needs to adopt the Information Telecommunication technology to the construction field as an integrated support system. In this paper, we proposed the continuous positioning tracking algorithm for workers and moving cars using the selected wireless communication network. And we proposed the virtual gateway method to detect the entrance status of moving workers and cars. All of these proposed methods are evaluated in real construction field using the prototype of support system made by ourselves.

• The Journal of the Acoustical Society of Korea
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• v.40 no.2
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• pp.161-168
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• 2021

In this paper, a Silent Speech Interface (SSI) technology was proposed in which Doppler frequency shifts of the reflected signal were used to synthesize the speech signals when 40kHz ultrasonic signal was incident to speaker's mouth region. In SSI, the mapping rules from the features derived from non-speech signals to those from audible speech signals was constructed, the speech signals are synthesized from non-speech signals using the constructed mapping rules. The mapping rules were built by minimizing the overall errors between the estimated and true speech parameters in the conventional SSI methods. In the present study, the mapping rules were constructed so that the distribution of the estimated parameters is similar to that of the true parameters by using Generative Adversarial Networks (GAN). The experimental result using 60 Korean words showed that, both objectively and subjectively, the performance of the proposed method was superior to that of the conventional neural networks-based methods.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.85-89
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• 1998

Effect of soil residue paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) on growth of barley (Hordeum vulgare L. cv. Sacheon No.6 and cv. Tapgolbori) and soybean [Glycine max (L.) Merr. cv. Alcheon and Danyeop] was investigated. Changes in soil residue paraquat during the cultivation period and residue amount in the p1ants at harvest were also determined. Experiments were conducted at two paraquat residue conditions; the first was done in an apple orchard soil where paraquat residue recorded 30.2 ppm in 1996, but decreased to about 9 to 9.8 ppm at the time of crop seeding and the second was conducted in the soil fortified to about 27 to 32 ppm paraquat residue. In both conditions, no crop injury due to the residue paraquat was observed and number of emerged seedlings and plant height of the two crops were not affected by soil residue paraquat. Residue amount of paraquat in the plants occurred less than 0.5 ppm detection limit. At the first condition, soil residue paraquat was further slightly decreased for 90 days after seeding, while no great change in the residue level was found at the second condition for 30 days after seeding. The results suggest that no carry-over effect occurs at about 30 ppm of soil residue paraquat and at present crop cultivation in Korean orchard soils are safe with respect to crop growth and paraquat residue in the plants.

• Journal of Korea Multimedia Society
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• v.8 no.11
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• pp.1439-1448
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• 2005

In this paper, after similarity of color information in above toro and geometry position analysis of important characteristic information in face and abstraction object that is inputted detects face area using comparison, describe about method to do user certification using ratio information and hair spring degree. Face abstraction algorithm that use color information has comparative advantages than face abstraction algorithm that use form information because have advantage that is not influenced facial degree or site etc. that tip. Because is based on color information, change of lighting or to keep correct performance because is sensitive about color such as background similar to complexion is difficult. Therefore, can be used more efficiently than method to use color information as that detect characteristic information of eye and lips etc. that is facial importance characteristic element except color information and similarity for each object achieves comparison. This paper proposes system that eye and mouth's similarity that calculate characteristic that is ratio red of each individual after divide face by each individual and is segmentalized giving weight in specification calculation recognize user confirming similarity through search. Could experiment method to propose and know that the awareness rate through analysis with the wave rises.

• Journal of the Mineralogical Society of Korea
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• v.5 no.1
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• pp.22-31
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• 1992

The Sancheong kaolin was fractionated into 9 size fractions by wet sieving, sedimentation, and centrifugation. The systematic X-ray diffraction combined with electron microscopy shows that the clay mineral composition of each size fraction is related to the original fabric of kaolin. Minerals such as halloysite (10${\AA}$), kaolinite, illite, and goethite which were formed by procipitation from solution are generally concentrated in the finer fractions, whereas verniculite which was formed by pseudomorphic transformation from other primary minerals are concentrated in the coarser factions. Kaolinits of various types which were formed by precipitation or transformation show a wide size range but they are generally concentrated in the coarser fractions. Halloysite or halloysite-kaolinite clusters in coarse fractions are the fragmentation products of the walls of original boxwork clusters in coarse fractions are the fragmentation products of the walls of original boxwork kaolin which escaped the complete dispersion even through the grinding, ultrasonic agitation, and chemical treatment. Separation of fully hydrated halloysite and kaolinite was possible by systematic wet size fractionation. The coarse-grained minerals such as vermiculite and kaolinite are usually removed during the preparation of clay fraction smaller than 2${\mu}m$, whereas the fine-grained minerals such as illite and goethite are overlooked in X-ray diffraction of the bulk samples because of their minor contents. The systematic wet size fractionation is needed for understanding of the exact mineralogy of kaolin of weathering origin.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.292-301
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• 2016

Because damages arising from the occurrence of foot-and-mouth disease (FMD) are very great, it is essential to make a preemptive diagnosis to cope with it in order to minimize those damages. The main symptoms of foot-and-mouth disease are body temperature increase, loss of appetite, formation of blisters in the mouth, on hooves and breasts, etc. in a cow or a bull, among which the body temperature check is the easiest and quickest way to detect the disease. In this paper, an algorithm to detect FMD from the hooves of cattle was developed and implemented for preemptive coping with foot-and-mouth disease, and a hoof check test is conducted after the installation of a high-resolution camera module, a thermo-graphic camera, and a temperature/humidity module in the cattle shed. Through the algorithm and system developed in this study, it is possible to cope with an early-stage situation in which cattle are suspected as suffering from foot-and-mouth disease, creating an optimized growth environment for cattle. In particular, in this study, the system to cope with FMD does not use a portable thermo-graphic camera, but a fixed camera attached to the cattle shed. It does not need additional personnel, has a function to measure the temperature of cattle hooves automatically through an image algorithm, and includes an automated alarm for a smart phone. This system enables the prediction of a possible occurrence of foot-and-mouth disease on a real-time basis, and also enables initial-stage disinfection to be performed to cope with the disease without needing extra personnel.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.83-92
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• 2005

D-OCSP-KIS proposed by Koga and Sakurai not only reduces the number or OCSP Responder's certificate but also criers the certificate status validation about OCSP Responder to the client. Therefore, D-OCSP-KIS is an effective method that can reduce the communication cost, computational time and storage consumption in client, but it has some problems. In case an attacker accidentally acquires an OCSP Responder's session private key in a time period (e.g., one day), she can disguise as the OCSP Responder in the time period unless the OCSP Responder recognizes. She can offer the wrong response to the client using the hash value intercepted. And the server and user on I-commerce can have a serious confusion and damage. And the computation and releasing of hash chain can be a load to CA. Thus, we propose a method detecting immediately the exposure of an OCSP Responder's session private key and the abuse of hash value in D-OCSP-KIS.