• ETRI Journal
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• v.37 no.5
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• pp.1012-1022
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• 2015

Conventional cryptographic algorithms are not sufficient to protect secret keys and data in white-box environments, where an attacker has full visibility and control over an executing software code. For this reason, cryptographic algorithms have been redesigned to be resistant to white-box attacks. The first white-box AES (WB-AES) implementation was thought to provide reliable security in that all brute force attacks are infeasible even in white-box environments; however, this proved not to be the case. In particular, Billet and others presented a cryptanalysis of WB-AES with 230 time complexity, and Michiels and others generalized it for all substitution-linear transformation ciphers. Recently, a collision-based cryptanalysis was also reported. In this paper, we revisit Chow and others's first WB-AES implementation and present a conditional re-encoding method for cryptanalysis protection. The experimental results show that there is approximately a 57% increase in the memory requirement and a 20% increase in execution speed.

• Journal of Magnetics
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• v.22 no.2
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• pp.275-280
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• 2017

A magnetic-field tunable 2.4 GHz microwave bandpass filter having insertion loss < -5dB on an FR4 substrate with the flaky magnetic material was designed and characterized. The tunability in the designed bandpass filter was achieved by adhering soft magnetic materials on top of the device. This soft magnetic material can be composed of ferromagnetic substance or ferrimagnetic substance. The performance of the designed bandpass filter under its influence is investigated. The frequency offset ratio changes over 30 %. There is over 20 % change in the center frequency towards the lower frequency region due to this application. These magnetic material layers achieved the center frequency shift and bandwidth extension without actually changing the original structure of the device.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.4
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• pp.320-329
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• 2016

An implicit method of solving the six degree-of-freedom rigid body motion equations based on the second order Adams-Bashforth-Moulten method was utilised as an improvement over the leapfrog scheme by making modifications to the rigid body motion solver libraries directly. The implementation will depend on predictor-corrector steps still residing within the hybrid Pressure Implicit with Splitting of Operators - Semi-Implicit Method for Pressure Linked Equations (PIMPLE) outer corrector loops to ensure strong coupling between fluid and motion. Aitken's under-relaxation is also introduced in this study to optimise the convergence rate and stability of the coupled solver. The resulting coupled solver ran on a free floating object tutorial test case when converged matches the original solver. It further allows a varying 70%-80% reduction in simulation times compared using a fixed under-relaxation to achieve the required stability.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.5
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• pp.325-329
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• 2020

Classic anesthetic techniques for the inferior alveolar nerve, lingual nerve, and long buccal nerve blockade are achieved by estimating the intended location for anesthetic deposition based on palpation, inspection, and subsequent correlation for oral anatomical structures. The present article utilizes computed tomography (CT) data to 3D print a guide for repeatable and accurate deposition of a local anesthetic at the ideal location. This technical report aims to anatomically define the ideal location for local anesthetic deposition. This process has the potential to reduce patient discomfort, risk of nerve damage, and failed mandibular anesthesia, as well as to reduce the total anesthetic dose. Lastly, as robotic-based interventions improve, this provides the initial framework for robot-guided regional anesthesia administration in the oral cavity.

• Industrial Engineering and Management Systems
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• v.11 no.3
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• pp.241-254
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• 2012

To gain competitive advantage in a fast changing environment, the higher education institution (HEI) must continuously adjust the strategies to that environment. One important strategy is how to determine appropriate practical actions based on what students really need and want. Despite the abundance of research on service quality management, there is no universal consensus on how best to determine appropriate practical actions in HEIs. The aim of this paper is to develop an integrated model to be used to accurately acquire the most critical service attributes and determine appropriate actions that promote student satisfaction. Drawing on relevant literature, an integrated model is proposed which is based on students' perspective by integrating the fuzzy SERVQUAL, refined Kano, and Blue Ocean model. Subsequently, an empirical case study in the higher education sector is described that illustrates the value of the model in determining the most critical attributes and how to improve them.

• Journal of Power Electronics
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• v.12 no.5
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• pp.689-698
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• 2012

This paper investigates the effects of applying different input current waveshapes on the performance of a continuous-conduction-mode (CCM) power-factor-correction (PFC) boost pre-regulator. It is found that the output voltage ripple of the pre-regulator can be reduced if the input current is modified to include controlled amount of higher order harmonics. This finding allows us to balance the performance of output regulation and the harmonic current emission when coming to the design of the pre-regulator. An experimental PFC boost pre-regulator prototype is constructed to verify the analysis and show the benefit of the pre-regulator operating with input current containing higher order harmonics.

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.2
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• pp.45-53
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• 1981

Long term precipitation gaging station record (58 years) was analyzed by progressive mean method to compare the estimated effective period of records for computing mean and probable values. Obtained results are as follows: 1. Fifty-eight years precipitation records at Jinju, Gyeong Sang Nam Do was analyzed by double mass analysis method. Result was appeared that the record was consistent with time. 2. The effective period of records for estimating mean values with the departure of 5% or less from the true mean are up to 33 years for annual precipitation, 20 years for annual maximum daily precipitation and 45 years for maximum successive dry days in summer season. 3. To estimate the probable values by Gumbel-Chow method within the departure of 5% level from true value, periods of 51 years, 38 years and 45 years were required for annual precipitation, annual maximum daily precipitation and maximum successive dry days in summer season, respectively.

• Journal of the Korean Statistical Society
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• v.34 no.4
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• pp.263-272
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• 2005

Let {$X_n,\;n{\ge}1$} be a sequence of negatively associated random variables which are dominated randomly by another random variable. We discuss the limit properties of weighted sums ${\Sigma}^n_{i=1}a_{ni}X_i$ under some appropriate conditions, where {$a_{ni},\;1{\le}\;i\;{\le}\;n,\;n\;{\ge}\;1$} is an array of constants. As corollary, the results of Bai and Cheng (2000) and Sung (2001) are extended from the i.i.d. case to not necessarily identically distributed negatively associated setting. The corresponding results of Chow and Lai (1973) also are extended.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.99-104
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• 2014

Platycodon grandiflorum have been used as a traditional remedy and food source. This study was performed to investigate the immunomodulating effects of Platycodon grandiflorum in mouse, using ex vivo experiments. Six to seven-week old mice were fed ad libitum on a chow diet, and water extract of Platycodon grandiflorum was orally administrated at two different concentractions (50 and 500 mg/kg B.W./day) every other day for four weeks. In ex vivo experiments, the highest proliferation of splenocytes and levels of cytokine (IL-$1{\beta}$, IL-6, TNF-${\alpha}$) production were observed in 500 mg/kg BW/day supplementation group for all three cytokines stimulated by LPS. In conclusion, this study suggests that Platycodon grandiflorum extracts may enhance the immune function by regulating the splenocytes proliferation and cytokine production capacity by activating macrophages in mice.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.456-463
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• 1997

Atrium buildings are commonly found in Hong Kong since 1980. Those spaces are usually crowded with people and so fire protection systems have to be installed for providing a safe environment. Smoke control system was identified to be important but no clear design guidelines are available because the smoke filling process was not well-understood. In this paper., Computational Fluid Dynamics(CFD) or fire field model is applied to study the smoke filling pattern in atrium. Two common cases on smoke spreading out from a shop adjacent to the atrium; and with a fire located at the atrium floor itself were considered. Simulations with a modified form of the CFD package TEAM were performed. Application of the predicted results Is illustrated.