• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.559-567
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• 2012

The storage quality of ready-to-eat Campbell table grapes which were packaged under modified atmospheres was investigated in order to examine the effect of high $O_2$ and $CO_2$ on the fruit. Fresh table grapes with 10-15 berries were packed into polypropylene (PP) trays and were top-sealed with polythylene terephthalate/PP film. The initial gas compositions inside the packages were air, 20% $O_2$/10% $CO_2$/70% $N_2$, and 40% $O_2$/60% $N_2$. Sealed packages with low density polyethylene film bags and perforated PP trays were also used as a further treatment and control, respectively. The quality attributes were assessed during storage at $5^{\circ}C$ for 28 days. Fruit packaged in high $CO_2$ concentration showed the lowest viable cell counts of inherent microorganisms among all samples, although they suffered from severe off-flavors. High levels of $O_2$ significantly lowered flesh weight loss and maintained the flavor of grape. In an overall sensory aspect, the high $O_2$ and $CO_2$ packages exhibited greater scores than the air and control at the end of the storage period. Other quality attributes showed no significant differences among treatments. Results suggest that packaging with an appropriate combination of high $O_2$ and $CO_2$ can be used as an effective processing treatment for improvement of the storability of ready-to-eat table grapes.

• Journal of radiological science and technology
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• v.37 no.3
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• pp.203-209
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• 2014

Usefulness and clinical availability for surgery efficiency were evaluated by conducting pre-operative planning with a model manufactured by desktop 3D printer by using clavicle CT image. The patient-customized clavicle fracture model was manufactured by desktop 3D printer of FDM wire laminated processing method by converting the CT image into STL file in Open Source DICOM Viewer Osirix. Also, the model of the original shape before damaged was restored and manufactured by Mirror technique based on STL file of not fractured clavicle of the other side by using the symmetry feature of the human body. For the model, the position and size, degree of the fracture was equally printed out. Using the clavicle model directly manufactured with low cost and less time in Department of Radiology is considered to be useful because it can reduce secondary damage during surgery and increase surgery efficiency with Minimal invasive percutaneous plate osteosynthesis(MIPO).

• Transactions of Materials Processing
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• v.23 no.8
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• pp.501-506
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• 2014

Progressive shearing with blanking dies is commonly employed to produce large quantities of tiny sheet metal electronic parts. Sheet metal pins, which are narrow and long, that are sheared with a progressive die set are often twisted. The twist in the sheet metal pins, which usually occurs in the final shearing operation, generally decreases with increasing blank holding force. The blank holding forces in all shearing operations are not the same because of different shearing positions and areas. In the current study, the optimal layout of the springs in a progressive die set to minimize the twist of the sheet metal pin is proposed. In order to find the holding force acting on the tiny narrow blanks produced with the proposed springs during the shearing process, the equivalent area method is used in the structural analysis. The shearing of the sheet-metal pin was simulated to compute the twist angle associated with the blank holding force. The constraint condition satisfying the pre-set blank holding force from the previous shearing operations was imposed. A design of experiments (DOE) was numerically implemented by analyzing the progressive die structure and by simulating the shearing process. From the meta-model created from the experimental results and by using a quadratic response surface method (PQRSM), the optimal layout of the springs was determined. The twist of sheet metal pin associated with the optimal layout of the springs found in the current study was compared with that of an existing progressive die to obtain a minimal amount of twist.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.37-50
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• 2009

The SCADA(Supervisory Control And Data Acquisition) system is a control system for infrastructure of nation. In the past, the SCADA system was designed without security function because of its closed operating environment. However, the security of the SCADA system has become an issue with connection to the open network caused by improved technology. In this paper we review the constraints and security requirements for SCADA system and propose advanced key management architecture for secure SCADA communications. The contributions of the present work are that our scheme support both message broadcasting and secure communications, while the existing key management schemes for SCADA system don't support message broadcasting. Moreover, by evenly spreading much of the total amount of computation across high power nodes (MTU or SUB-MTU), our protocol avoids any potential performance bottleneck of the system while keeping the burden on low power (RTU) nodes at minimal.

• The korean journal of orthodontics
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• v.53 no.3
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• pp.139-149
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• 2023

Objective: To assess the color stability and translucency of full cubic stabilized zirconia (FSZ) following orthodontic bonding with different surface treatments and coffee thermocycling (CTC). Methods: This in vitro study was conducted on 120 disc-shaped specimens of FSZ. Thirty specimens were selected as the control group and remained intact. The remaining specimens were randomly divided into three groups based on the type of surface treatment (n = 30): airborne particle abrasion (APA), silica-coating (CoJet), and carbon dioxide (CO₂) laser. After metal bracket bonding in the test groups, debonding and polishing were performed. Subsequently, all specimens underwent CTC (10,000 cycles). Color parameters, color difference (ΔE₀₀), and translucency parameter (TP) were measured three times at baseline (t0), after debonding and polishing (t1), and after CTC (t2). Data were statistically analyzed (α = 0.05). Results: Significant difference existed among the groups regarding ΔE₀₀t0t2 (p < 0.001). The APA group showed minimum (ΔE₀₀ = 1.15 ± 0.53) and the control group showed maximum (ΔE₀₀ = 0.19 ± 0.02) color stability, with no significant difference between the laser and CoJet groups (p = 0.511). The four groups were significantly different regarding ΔTPt0t2 (p < 0.001). Maximal increases in TP were noted in the CoJet (1.00 ± 0.18) and APA (1.04 ± 0.38) groups while minimal increase was recorded in the control group (0.1 ± 0.02). Conclusions: Orthodontic treatment makes zirconia restorations susceptible to discoloration and increased translucency. Nonetheless, the recorded ΔE₀₀ and ΔTP did not exceed the acceptability threshold.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.220-227
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• 2016

Marine seismic data have not only primary signals from subsurface but also ghost signals reflected from the sea surface. The ghost decreases temporal resolution of seismic data because it attenuates specific frequency components. For eliminating the ghost signals effectively, the exact ghost delaytimes and reflection coefficients are required. Because of undulation of the sea surface and vertical movements of airguns and streamers, the ghost delaytime varies spatially and randomly while acquiring seismic data. The reflection coefficient is a function of frequency, incidence angle of plane-wave and the sea state. In order to estimate the proper ghost delaytimes considering these characteristics, we compared the ghost delaytimes estimated with L-1 norm, L-2 norm and kurtosis of the deghosted trace and its autocorrelation on synthetic data. L-1 norm of autocorrelation showed a minimal error and the reflection coefficient was calculated using Kirchhoff approximation equation which can handle the effect of wave height. We applied the estimated ghost delaytimes and the calculated reflection coefficients to remove the source and receiver ghost effects. By removing ghost signals, we reconstructed the frequency components attenuated near the notch frequency and produced the migrated stack section with enhanced temporal resolution.

• The KIPS Transactions:PartB
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• v.15B no.4
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• pp.275-284
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• 2008

With increases in recent security requirements, biometric technology such as fingerprints, faces and iris recognitions have been widely used in many applications including door access control, personal authentication for computers, internet banking, automatic teller machines and border-crossing controls. Finger vein recognition uses the unique patterns of finger veins in order to identify individuals at a high level of accuracy. This paper proposes new device and methods for touchless finger vein recognition. This research presents the following five advantages compared to previous works. First, by using a minimal guiding structure for the finger tip, side and the back of finger, we were able to obtain touchless finger vein images without causing much inconvenience to user. Second, by using a hot mirror, which was slanted at the angle of 45 degrees in front of the camera, we were able to reduce the depth of the capturing device. Consequently, it would be possible to use the device in many applications having size limitations such as mobile phones. Third, we used the holistic texture information of the finger veins based on a LBP (Local Binary Pattern) without needing to extract accurate finger vein regions. By using this method, we were able to reduce the effect of non-uniform illumination including shaded and highly saturated areas. Fourth, we enhanced recognition performance by excluding non-finger vein regions. Fifth, when matching the extracted finger vein code with the enrolled one, by using the bit-shift in both the horizontal and vertical directions, we could reduce the authentic variations caused by the translation and rotation of finger. Experimental results showed that the EER (Equal Error Rate) was 0.07423% and the total processing time was 91.4ms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.7
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• pp.1071-1077
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• 2022

A security SoC that can be used to implement elliptic curve cryptography (ECC) based public-key infrastructures was designed. The security SoC has an architecture in which a hardware accelerator for the elliptic curve digital signature algorithm (ECDSA) is interfaced with the Cortex-A53 CPU using the AXI4-Lite bus. The ECDSA hardware accelerator, which consists of a high-performance ECC processor, a SHA3 hash core, a true random number generator (TRNG), a modular multiplier, BRAM, and control FSM, was designed to perform the high-performance computation of ECDSA signature generation and signature verification with minimal CPU control. The security SoC was implemented in the Zynq UltraScale+ MPSoC device to perform hardware-software co-verification, and it was evaluated that the ECDSA signature generation or signature verification can be achieved about 1,000 times per second at a clock frequency of 150 MHz. The ECDSA hardware accelerator was implemented using hardware resources of 74,630 LUTs, 23,356 flip-flops, 32kb BRAM, and 36 DSP blocks.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.95-102
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• 2015

The Maillard reaction is a non-enzymatic reaction between amino and carbonyl groups. During milk processing, lactose reacts with milk protein through this reaction. Infant formulas (IFs) are milk-based products processed with heat-treatments, including spray-drying and sterilization. Because IFs contain higher Maillard reaction products (MRPs) than breast milk, formula-fed infants are subject to higher MRP exposure than breast milk-fed ones. In this study, we investigated the optimization of conditions for minimal MRP formation with the addition of $\small{L}$-carnitine ($\small{L}$-car), pyridoxine hydrochloride (PH), and $\small{DL}$-${\alpha}$-tocopheryl acetate (${\alpha}$-T) in an IF model system. MRP formation was monitored by response surface methodology using fluorescence intensity (FI) and 5-hydroxymethylfurfural (HMF) content. The optimal condition for minimizing the formation of MRPs was with $2.3{\mu}M$ $\small{L}$-car, $15.8{\mu}M$ PH, and $20.6{\mu}M$ ${\alpha}$-T. Under this condition, the predicted values were 77.4% FI and 248.7 ppb HMF.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.69-75
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• 2008

This study evaluated the physicochemical and sensory characteristics of vanilla ice cream treated with gamma irradiation. The general composition of the vanilla ice cream used for the study was 45.4-53.3% moisture, 5.5-5.9% fat and 3.9-4.1% protein, and these values did not change following gamma irradiation. The Hunter L, a and b values were slightly decreased following gamma irradiation. The fatty acid composition of the ice cream included caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid and stearic acid, and there was no detectable change following irradiation. There was no significant difference in TBARS (2-thiobarbituric acid reactive substances) values between non-irradiated and irradiated samples at a dose of 3 kGy or less (p<0.05). Sensory evaluation indicated that gamma-irradiated vanilla ice cream did not show any difference in color relative to non-irradiated ice cream. However, gamma irradiation did affect the flavor, taste and overall acceptability of ice cream at doses above 3 kGy. These results indicate that gamma irradiation at 3 kGy is an effective treatment for sustaining the physicochemical characteristics of vanilla ice cream with minimal changes in sensory characteristics, though further studies should be carried out to reduce the deterioration of sensory qualities induced by gamma irradiation.