• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.129-135
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• 2016

Various type of valves are manufactured for different industrial uses. Among them, check valves are used to allow fluid to flow in one direction but not in the opposite direction. There are many different types of check valves, but Y-shaped check valves are widely used these days. Not many studies have been carried out on Y-shaped check valves and the flow coefficients obtained through numerical analysis have the problem of low reliability. In order to solve this problem, this study performed flow analysis, flow-structure coupled analysis, and flow coefficient measurement experimentally, and through these analyses derived and verified the flow coefficients and assessed the structural safety based on numerical analysis.

• Journal of the Semiconductor & Display Technology
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• v.8 no.4
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• pp.77-82
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• 2009

In robot operation, a motor with multi-degree of freedom motion control and an encoder for motor control are needed. To perform precise motion, location, and velocity control, the operation of motor and encoder with superior performance is important. In this paper, we studied performance evaluation system that can evaluate the performance of motor and encoder. The performance of motor and encoder can be evaluated in terms of disconnection check, signal variation count, and U, V, W signal check. Disconnection check verifies signal connection between a motor and an encoder, signal variation check verifies A, B signal by counting the number of signal A, B when a motor revolves, and U, V, W signal check verifies operating direction of a motor. The result is shown at graphic LCD integrated in system, and can be checked in PC with PC communication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4C
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• pp.310-317
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• 2006

In this paper, we propose a new sequential message-passing decoding algorithm of low-density parity-check (LDPC) codes by partitioning check nodes. This new decoding algorithm shows better bit error rate(BER) performance than that of the conventional message-passing decoding algorithm, especially for small number of iterations. Analytical results tell us that as the number of partitioned subsets of check nodes increases, the BER performance becomes better. We also derive the recursive equations for mean values of messages at variable nodes by using density evolution with Gaussian approximation. Simulation results also confirm the analytical results.

• Journal of the Korea Society of Computer and Information
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• v.18 no.3
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• pp.59-68
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• 2013

In this study, airport security check process is analyzed to modeling a simulation. Simulation is compared with real security system to verify. Utilizing verified simulation, spends time in the current security check is calculated and suggests alternatives. Considering the movement of passengers and security check system of all four cases the results yielded by the experiment. The results show that security check time decreased significantly to 20.8%. The simulation was developed in this study; including the introduction of a new security system at security check can be used as a decision support tool is expected.

• Computers and Concrete
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• v.22 no.2
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• pp.133-142
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• 2018

The deterioration of existing bridges has become a major problem around the world. In the paper, a new model and an associated stress checking method are proposed for concrete box girders strengthened by external prestressing. The new model called the spatial grid model can analyze all the spatial behaviors clearly by transforming the box girder into discrete orthogonal grids which are equivalent to plate elements. Then the three-layer stresses are employed as the stress checking indices to evaluate the stress state of the plate elements. The initial stress check before strengthening reveals the cracked and potential cracking areas for existing bridges, making the strengthening design more targeted and scientific; the subsequent stress check after strengthening evaluates the strengthening effect and ensures safety. A deficient bridge is selected as the practical example, verifying the accuracy and applicability of the proposed model and stress checking method. The results show that principal stresses in the middle layer of plate elements reflect the main effects of external prestressing and thus are the key stress checking indices for strengthening. Moreover, principal stresses check should be conducted in all parts of the strengthened structure not only in the webs. As for the local effects of external prestressing especially in the areas near anchorage and deviator, normal stresses check in the outer and inner layers dominates and local strengthening measures should be taken if necessary.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.87-92
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• 2007

Twenty - four elite mulberry germplasm each of indigenous and exotics were studied for their leaf yield and compared with commercial check ($V_1$ and Kosen). Accession MI-0416 and ME-0169 out yielded the check accession in leaf yield/plant. The other few mulberry germplasm were also performed at par with the checks. For quality test and bioassay were conducted with the leaves of selected mulberry germplasm. Among the selected twelve mulberry accessions used for bioassay, MI-0376 and ME-033 performed better than check ($V_1$, Kosen). Other mulberry accessions i.e., MI-0310 and MI-0437 are on par with the check as far as the bioassay is concerned. MI-0376 and ME-0033 out yielded in rearing parameters and qualified for 11 and 10 rearing and related traits. Other mulberry accessions i.e., MI-0310 and MI-0437 were also qualified for eight rearing traits along with check ($V_1$). The mulberry accessions tested after selection from the preliminary characterization seems to be better and equally good in rearing and leaf yield compared to check ($V_1$, Kosen), which provides scope for selection and further evaluation. The selected mulberry accession may be included in crop improvement programme.

• English & American cultural studies
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• v.14 no.2
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• pp.49-75
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• 2014

This paper argues that John Leguizamo disguises ethical intention with humor in his one-person show, Freak. The argument proceeds in three stages. First, on the basis of Slavoj ${\check{Z}}i{\check{z}}ek^{\prime}s$ theory that fantasies teach us how to desire discussed in The Sublime Object of Ideology, I analyze how and why Leguizamo exaggerates and thus de-constructs the ideological fantasies about Latin Americans in Freak. Through this analysis the ridiculous exaggeration of the fantasies and their deconstruction emerges as the means to surface the trauma caused by the fantasies, internally and externally curing and reconciling the audience. Second, I apply ${\check{Z}}i{\check{z}}ek^{\prime}s$ theory of the quilting point introduced in Looking Awry: An Introduction to Jacques Lacan through Popular Culture to reveal how "blots" in Freak form "black holes" in the audience's consciousness to smash their established view of the reality, inducing them to encounter with "the real." The investigation into Leguizamo's use of humor as the quilting point illuminates how he invites the audience to look awry beyond the popular fantasy at "the real" America. Third, on the ground of Emmanuel Levinas's theory that theaters are the space of ethics, namely "ethotopos" to emphasize responsible actions discussed in "Ethics as First Philosophy," I assert that Leguizamo disguises his ethical message with humor so as for the audience to recognize their responsibility for others in America and take action towards change.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.3
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• pp.54-64
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• 2022

Airlines have been introducing self check-in kiosks to reduce check-in time and improve operational efficacy to increase business revenue. The domestic airlines have actively provided kiosks at airports which are expected to reduce their operating costs and enrich their passengers' travel convenience. Based on the above background, the study investigates the factors influencing intention to use the self check-in kiosks by employing the Extended Technology Acceptance Model (ETAM). The study, therefore, designed a research model by reviewing theories and studies on the relationship among information quality, innovativeness, perceived ease of use, perceived usefulness, and intention to use the kiosks. The structural equation model revealed the following. Information quality and innovativeness had a significantly positive influence on perceived ease of use and perceived usefulness; furthermore, perceived ease of use had a significantly positive influence on perceived usefulness. In addition, both perceived ease of use and perceived usefulness had a significantly positive influence on intention to use. The results indicate that the airlines should constantly develop user-friendly contents and design of the self check-in kiosks.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.302-314
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• 2016

This study was carried out to confirm the effects of the knife-incising and kerfing pretreatment on the moisture content and surface check occurrence of Douglas-fir heavy timber. In the case of moisture content, the moisture gradient that formed in the inner part of the specimen was observed in all specimens. In addition, the moisture gradient was formed differently from the surface layer to 72 mm depending on the pretreatment conditions, and it was formed gradually in the kerfing than the knife-incising. In addition, it was found that the solid volume should be considered when measuring the average moisture content. In the case of surface check, the surface check occurrence was reduced in the knife-incising, kerfing, and the combination of knife-incising and kerfing than the control. In particular, the kerfing treatment was shown that the expansion of surface check width was effectively suppressed. In the case of knife-incising treatment, although the surface check was less than the control, the preventive effect on the surface check occurrence did not reach the level of the kerfing treatment.

• Journal of Aerospace System Engineering
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• v.12 no.5
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• pp.32-39
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• 2018

In this paper, the calculation of the theoretical pressure transfer ratio due to the deformation of the thin-plate spring type check valve applied to the small piezoelectric-hydraulic pump was carried out. A thin-plate check valve is a flexible body that is deformed by an external force. The deformation of the check valve affects the rate at which the chamber pressure is transferred to the load pressure. The theoretical pressure transfer ratio for each model was calculated to compare the difference between the assumption that the thin-plate check valve is a rigid body and that of the flexible body model. The P-delta effect was considered for the calculation of the pressure transfer ratio of the flexible check valve model. In addition, a verification test for the calculated pressure transfer ratio obtained by considering the deformation of the flexible check valve model was carried out. The load pressure was measured by applying a thin-plate and ball-thin plate spring type check valves, respectively. The experimental pressure transfer ratio was calculated using the respective load pressure obtained from the experiments. The validity of the pressure transfer analysis of the check valve, taking into consideration the P-delta effect, was verified by comparing it with the theoretically calculated pressure transfer ratio.