• Journal of Welding and Joining
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• v.14 no.1
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• pp.99-106
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• 1996

Development of an automatic TIG welding system incorporating a vision sensor and torch control mechanism leads to an improved welding quality and greater production efficiency. The automatic welding system should be greatly restricted in its size and weight for the LNG(Liquefied Natural Gas) storage tank and also provide a unique torch rotating mechanism which keeps the torch tip in the constant position while the angle is changed continuously to maintain the welding torch substantially perpendicular to the weld line. The developed system is driven by two translation axes X, Z and one rotational axis. A moving line window method is adopted to the image recognition of the corrugated membranes with specular reflection. This method decides original laser stripe patterns in image which is affected by multi-reflection. A self-teaching algorithm, which guides the automatic welding machine with the information provided by the CCD camera without any previous learning of a reference trajectory, was developed for tracking the corrugated membrane of the LNG tank along the weld line.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.12
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• pp.817-821
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• 2017

As a ZnO varistor is subjected to electrical and environmental stresses, it degrades gradually, which may result in power interruption by short circuit. This study investigates changes in the electrical characteristics of ZnO varistors due to deterioration owing to energy absorption, and determines the optimal parameters for on-line diagnosis of the varistor. Two types of varistors were used for an accelerated aging experiment involving the application of the $8/20{\mu}s$ standard lightning impulse current. The electrical characteristics in terms of the reference voltage, total leakage current, resistive leakage current, and third-harmonic component of the total leakage current were measured, and their change rates were analyzed. The results revealed that the total leakage current increased slightly with an increase in the varistor absorbed energy, while the resistive leakage current and the third-harmonic component increased apparently. Therefore, the third-harmonic component of the total leakage current was proposed as the optimal parameter for on-line monitoring of ZnO varistor conditions.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.546-553
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• 2008

Purpose: The purpose of this study was to estimate validity of posterior anterior cephalometric and 3D-CT for orbital canting analysis. Materials and methods: Three trained observers classified two patients group using standardized frontal photographs of facial asymmetry patients. Group A consisted of patients with facial asymmetry and orbital canting(n=19), and group B consisted of patients with only facial asymmetry(n=43). Orbital canting was measured with line of bilateral inferior orbitale. Orbital canting measurement was done with posterior anterior cephalometric and 3D-CT. Each horizontal reference line was established by bilateral GWSO(cephalometric), FZS(3D-CT). Maxillary canting and mandibular deviation angle were also measured and analyzed with orbital canting. Results: The mean orbital canting was $3.03{\pm}1.00^{\circ}$ in Group A and $1.11{\pm}0.76^{\circ}$ in Group B in frontal photograph. The mean orbital canting was $1.20{\pm}0.74^{\circ}$ in group A and $1.22{\pm}0.65^{\circ}$ in group B by cephalometric analysis(p>0.05). In 3D-CT, orbital canting was almost paralleled with horizontal reference line. The orbital canting, maxillay canting and mandibular deviation between two groups showed no significant differences except madibular deviation in 3D-CT. Conclusion: Common analysis of posterior anterior cephalometric and 3D-CT is not valide method to evaluate orbital canting for facial asymmetry patients with orbital canting.

• International Commerce and Information Review
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• v.1 no.2
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• pp.69-95
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• 1999

Internet EC accomplish to simply electronic business from all process integration of production, marketing and customer service. Also customers gain to goods information by one-line product reference, order, product information exchange and negotiate to low cost for high quality goods. Therefore, Purpose of this study is to introduce the building method of efficient EC, helping understand EC, and analysing its present state in the Korean enterprises and efficiency on international trade information.

• Journal of the Optical Society of Korea
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• v.5 no.2
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• pp.60-66
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• 2001

The authors discuss a prototype stylus profilometer designed to measure large optics. It consists of a low contact force type probe system, laser reference system, interferometric distance measurement system, and horizontal driving system. The probe contacts the surface ; the height and the horizontal distances of the measurement points are measured by the interferometer. The freely propagated laser beam provides the reference line during the measurement. The developed stylus profilometry shows only $\pm$60 nm of P-V error for the 157 mm diameter spherical mirror.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.241-249
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• 2010

Companies and consumers are highly interested in online activities such as word-of-mouth(W.O.M) as marketing paradigm moved to online context. In this study, the research identified major variables affecting product review reference rate online and analyzed the difference based on those variables. According to the results, remarkable differences were discovered in four variable such as 'brand reference', 'review symbol', 'affirmation' and 'information offering'. In addition, the researcher found 'brand reference' and 'information offering' are most important factors deciding review reference rate using regression tree analysis method. Based on the results, the practical implications and further research directions for utilizing consumer online W.O.M were discussed.

• Journal of Power Electronics
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• v.5 no.2
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• pp.129-141
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• 2005

A high-performance robust hybrid speed controller for a permanent-magnet synchronous motor (PMSM) drive with an on-line trained neural-network model-following controller (NNMFC) is proposed. The robust hybrid controller is a two-degrees-of-freedom (2DOF) integral plus proportional & rate feedback (I-PD) with neural-network model-following (NNMF) speed controller (2DOF I-PD NNMFC). The robust controller combines the merits of the 2DOF I-PD controller and the NNMF controller to regulate the speed of a PMSM drive. First, a systematic mathematical procedure is derived to calculate the parameters of the synchronous d-q axes PI current controllers and the 2DOF I-PD speed controller according to the required specifications for the PMSM drive system. Then, the resulting closed loop transfer function of the PMSM drive system including the current control loop is used as the reference model. In addition to the 200F I-PD controller, a neural-network model-following controller whose weights are trained on-line is designed to realize high dynamic performance in disturbance rejection and tracking characteristics. According to the model-following error between the outputs of the reference model and the PMSM drive system, the NNMFC generates an adaptive control signal which is added to the 2DOF I-PD speed controller output to attain robust model-following characteristics under different operating conditions regardless of parameter variations and load disturbances. A computer simulation is developed to demonstrate the effectiveness of the proposed 200F I-PD NNMF controller. The results confirm that the proposed 2DOF I-PO NNMF speed controller produces rapid, robust performance and accurate response to the reference model regardless of load disturbances or PMSM parameter variations.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.94-99
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• 2016

Since development of the first Korean button mushroom cultivar 'Sae-Ah' in 2010, mushroom farmers have demanded an improved cultivar. Although a new cultivar, 'Saejeong', was developed in 2011, this cultivar has thus far been difficult to cultivate in typical mushroom farms. To solve this problem, another new cultivar, 'Saedo', was developed in 2012. This new cultivar was selected by genetic analysis from crossing the heterokaryon line A175 and the homokaryon line ASI1346-15. The heterokaryon A175 was a crossed line between strains ASI1038-211 and ASI1346-20. The mycelium of 'Saedo' showed good growth on compost dextrose agar at $25^{\circ}C$. The morphological traits such as the pileus (cap) and stipe of the 'Saedo' cultivar were thicker than those of the reference control 'Saejeong', and the production yield was increased by 1.89-fold compared to that of the reference control. A field experiment of the 'Saedo' cultivar has been ongoing since 2013. The yield of the 'Saedo' cultivar was found to be substantially higher than that of the reference control during the $2^{nd}$ flush.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.105-112
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• 1997

This study was carried out to examine the calculations including the ease amount for bodice pattern. The conclusions were as follows. The areas that were required the ease amount were the horizontal reference line, armhole depth, back & front width. According to this result the calculations including the ease amount were obtained as follows: B/2+4.1cm for horizontal reference line, B/6+6.8 cm for armhole depth, B/6+3.9 cm for the half of back width, B/6+2.3 cm for the half of front width, B/4+4.3 cm for bust point length.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.10
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• pp.635-640
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• 2016

This paper dealt with the deterioration characteristics and an on-line diagnosis equipment for SPDs (surge protective devices). An accelerated aging test was carried out using a $8/20{\mu}s$ standard lightning impulse current to analyze the changes of electrical characteristics and to propose the diagnostic parameters and the criterion for deterioration of ZnO varistor which is the core component of SPDs. Based on the experimental results, an on-line diagnosis equipment for SPD was fabricated, which can measure the total leakage current, reference and clamping voltage. The leakage current measurement circuit was designed using a low-noise amplifier and a clamp type ZCT. A linear controller, the leakage current measurement part and a HVDC were used in the measurement of reference voltage. The measurement circuit of clamping voltage consisted of a surge generator and a coupling circuit. In a calibration process, measurement error of the prototype equipment was less than 3%.