• Proceedings of the KIEE Conference
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• 대한전기학회 2007년도 학술대회 논문집 전문대학교육위원
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• pp.112-116
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• 2007

If any of the set parameters such as the environment temperature, mold temperature are not maintained at a consistent level, the fail rate of injection molding products is increased. The price of the injection molding machine is very high, so in order to maximize the utilization of the machine that is required the production of a number of different products with minimum fail rate using a single machine. To prevent the defect products by an inspection process with perfect quality is very important to minimizing production of defect products in the molding process. Vision inspection systems are widely utilized in various manufacturing industries for quality assurance purposes. The vision inspection system consists of CCD camera and lighting system to capture the image of the subject of inspection, an image comparison algorithm using to determine the pass/fail of the products, and mechanical devices for the operation of the whole system. This research focuses on the development of the vision inspection system to process the inspection of an automobile parts. We developed a mechanical devices for the inspection of the injection molding products and an image comparison algorithm to determine the pass/fail result of the inspection based on the molding image and the accepted product image.

• Journal of Korea Multimedia Society
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• 제23권11호
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• pp.1361-1371
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• 2020

Fonts have developed as a visual element, and their influence has rapidly increased around the world. Research on font automation is actively being conducted mainly in English because Hangul is a combination character and the structure is complicated. In the previous study to solve this problem, the stroke element of the character was automatically extracted by applying the object detection by component. However, the previous research was only for similarity, so it was tested on various print style fonts, but it has not been tested on other characters. In order to extract the stroke elements of all characters and fonts, we performed a performance analysis experiment according to the expansion character in the Hangul stroke element extraction training. The results were all high overall. In particular, in the font expansion type, the extraction success rate was high regardless of having done the training or not. In the character expansion type, the extraction success rate of trained characters was slightly higher than that of untrained characters. In conclusion, for the perfect Hangul stroke element extraction model, we will introduce Semi-Supervised Learning to increase the number of data and strengthen it.

• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1462-1470
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• 2020

Reliability in safety-critical systems and equipment is of vital importance, so the probabilistic safety assessment (PSA) has been widely used for many years in the nuclear industry to address reliability in a quantitative manner. As many nuclear power plants (NPPs) become digitalized, evaluating the reliability of safety-critical software has become an emerging issue. Due to a lack of available methods, in many conventional PSA models only hardware reliability is addressed with the assumption that software reliability is perfect or very high compared to hardware reliability. This study focused on developing a new method of safety-critical software reliability quantification, derived from hardware-software integrated environment testing. Since the complexity of hardware and software interaction makes the possible number of test cases for exhaustive testing well beyond a practically achievable range, an importance-oriented testing method that assures the most efficient test coverage was developed. Application to the test of an actual NPP reactor protection system demonstrated the applicability of the developed method and provided insight into complex software-based system reliability.

• Convergence Security Journal
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• 제14권2호
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• pp.25-33
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• 2014

With the development of information and communication, public institutions and enterprises utilize the business continuity using the Internet and Intranet. In this environment, public institutions and enterprises is to be introduced the number of solutions and appliances equipment to protect the risk of leakage of inside information. However, this is also the perfect external network connection is not enough to prevent leakage of information. To overcome these separate internal and external networks are needed. In this paper, we constructed the physical and logical network separation is applied to the network using the virtualization and thus the network configuration and network technical review of the various schemes were proposed for the separation.

• Journal of Communications and Networks
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• 제10권2호
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• pp.148-155
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• 2008

In wireless data communication systems, retransmission of an erroneous packet is inevitable due to the harsh communication environment. In this paper, an efficient retransmission scheme using cooperation from neighboring nodes is investigated. In the cooperative retransmission scheme, an erroneous packet is transmitted to the destination by cooperative nodes which have favorable channels. This cooperative retransmission scheme requires no a priori information of neighboring nodes and has no limitation on the number of cooperating nodes. Distributed beamforming is used to accommodate multiple cooperating nodes. Phase and frequency offsets of cooperating signals are extracted from the NACK message and used to co-phase retransmitted data packets. The outage probability of the cooperative retransmission scheme is analyzed for the case of perfect synchronization and when the offsets are estimated. To reduce the impact of the residual phase and frequency offsets in cooperating signals, a low-rate feedback scheme is also investigated. It is shown that improved outage probability and reduced packet error rate (PER) performance can be achieved even for long data packets. The proposed cooperative retransmission scheme is found to outperform simple retransmission by the source as well as decode-and-forward cooperation.

• Journal of the Korean Ceramic Society
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• 제47권1호
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• pp.19-25
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• 2010

Traditional Kr$\ddot{o}$ger-Vink (K-V) notation defines sites in ionic crystals as interstitial or belonging to host ions. It enables description and calculations of combinations of native and foreign defects, including dopants and substituents. However, some materials exhibit inherently disordered partial occupancy of ions and vacancies, or partial occupancy of two types of ions. For instance, the high temperature disordered phases of $Bi_2O_3$, $Ba_2In_2O_5$, $La_2Mo_2O_9$, mayenite $Ca_{12}Al_{14}O_{33}$, AgI, and $CsHSO_4$ are all good ionic conductors and thus obviously contain charged point defects. But traditional K-V notation cannot account for a charge compensating defect in each case, without resorting to terms like "100% substitution" or "Frenkel disorder". the former arbitrary and awkward and the latter inappropriate. Instead, a K-V compatible nomenclature in which the partially occupied site is defined as the perfect site, has been proposed. I here introduce it thoroughly and provide a number of examples.

• Speech Sciences
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• 제11권2호
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• pp.105-117
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• 2004

Recently, many scholars have emphasized the importance of English listening ability for smoother communication. Most audio materials, however, were recorded in a quiet sound-proof booth. Therefore, students who have spent so much time listening to the ideal audio materials are expected to have difficulty communicating with native speakers in the real life. In this study, we examined how well thirty three Korean university students and five native speakers will repeat the recorded English sentences under noise and speed conditions. The subjects' production was scored by listening to each recorded sentence and counting the number of words correctly produced and determined the percent ratios of correctly produced words to the total words in each sentence. Results showed that the student group correctly repeated around 65% of all the words in each sentence while the native speakers demonstrated almost perfect match. It seemed that the students had difficulty perceiving and repeating function words in various conditions. Also, high-proficiency student group outperformed the low-proficiency student group particularly in their repetition of function words. In addition, the student subjects' accuracy of repetition remarkably dropped when the normal sentences were both sped up and mixed with noise. Finally, it was observed that the Korean students' percent correct ratio fell down as the stimulus sentence became longer.

• International Journal of Precision Engineering and Manufacturing
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• 제7권4호
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• pp.40-46
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• 2006

The market of programmable implantable pumps has bound to a monopolistic situation, inducing high device costs, thus making them inaccessible to most patients. Micro-mechanical and medical innovations allow improved performances by reducing the dimensions. This affects the consumption and weight, and, by reducing the number of parts, the cost is also affected. This paper presents the procedure followed to design an innovative implantable drug delivery system. This drug delivery system consists of a low flow pump which shall be implanted in the human body to relieve pain. In comparison to classical known solutions, this pump presents many advantages of high interest in both medical and mechanical terms. The first section of the article describes the specifications which would characterize a perfect delivery system from every points of view. This concerns shape, medication, flow, autonomy, biocompatibility, security and sterilization ability. Afterwards, an overview of existing systems is proposed in a decisional tree. Positive displacement motorized pumps are classified into three main groups: the continuous movement group, the fractioned translation group and the alternative movement group. These systems are described and the different problems which are specific to these mechanisms are presented. Since none of them fully satisfy the specifications, an innovation is justified.. The decisional tree is therefore extended by adding new principles: fractioned refilling and fractioned injection within the fractioned translation movement group, spider guiding system within the alternative translation movement group, rotational bearing guided device and notch hinge guided device in the alternative rotation movement group.

• Archives of design research
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• 제15권1호
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• pp.81-92
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• 2002

Through network draft, it′s possible to describe curve draft with main motive in a lobby loom and to fulfill draft design more conveniently thanks to the development of computer device. Network draft was introduced by Alice Schlein, who is an American weaving artist, and I had ever published research paper on "The unfolding and development of network draft using computer dobby system" . The purpose of the next study was to develop the design of network draft while do make a design network draft in a dobby loom with 16 shafts, and could reach follow conclusion as a result of designing a variety of drafts. The initial of 4-end in a loom with 16 shafts was a basic condition to describe more perfect shape in comparison with draft in 8 shafts through the development of network. The development of draft line was essential to deride the pattern of fabric, and the pattern of draft is decided according to selecting key peg plan. Thereby, could get a variety of draft patterns derive from mix key peg plan with initial selected by developing the kind of draft line and applying diverse key peg plan. As for the variation and diversification of draft line, the shape of patters varied depending col the curve extent and connectivity of draft line and the size of curve. The pattern of network draft can be changed infinitely by free round curve of draft line. In addition, a variety of draft designs shall be developed by increasing the number of shaft, enlarging the scale of draft line, and developing more creative draft line.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제19권1호
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• pp.9-17
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• 2001

GPS is an efficient system in surveying and car navigation. but it is difficult to catch minimum number of satellite when it is hindered by obstacle such as city area. GLONASS system doesn't have perfect constellation yet, but it has many similarities with GPS system in principle of point positioning and signal system. so, it is expected to be much efficient when it is used with GPS system. For the purpose of this, the coordinates of GPS and GLONASS system, the quality of time and frequency was investigated, and the algorithm of point positioning was made. also, the efficiency of GPS/GLONASS combination was presented by analysing the precision of 3D point positioning using C/A code and Yuma satellite orbit information.