• Journal of Biomedical Engineering Research
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• v.45 no.3
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• pp.118-127
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• 2024

Commonly deep learning methods for enhancing the quality of medical images use unpaired dataset due to the impracticality of acquiring paired dataset through commercial imaging system. In this paper, we propose a supervised learning method to enhance the quality of ultrasound images. The U-net model is designed by incorporating a divide-and-conquer approach that divides and processes an image into four parts to overcome data shortage and shorten the learning time. The proposed model is trained using paired dataset consisting of 828 pairs of low-quality and high-quality images with a resolution of 512x512 pixels obtained by varying the number of channels for the same subject. Out of a total of 828 pairs of images, 684 pairs are used as the training dataset, while the remaining 144 pairs served as the test dataset. In the test results, the average Mean Squared Error (MSE) was reduced from 87.6884 in the low-quality images to 45.5108 in the restored images. Additionally, the average Peak Signal-to-Noise Ratio (PSNR) was improved from 28.7550 to 31.8063, and the average Structural Similarity Index (SSIM) was increased from 0.4755 to 0.8511, demonstrating significant enhancements in image quality.

• Journal of Bio-Environment Control
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• v.9 no.2
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• pp.115-119
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• 2000

Oak mushroom(Lentinus edoes(Berk) Sing) is one of the most important edible mushrooms, and its production has been rapidly increased due to nutritional and medicinal effects. In this study, climatic factors during the growing period of high-quality oak mushroom were analyzed and environmental factors affecting the quality of oak mushroom were discussed. Three places(Changheung, Puyo and Wonj) as mass producing areas of high-quality oak mushrooms and the 15 days of the growing period in 1997-1998 were selected. Major climatic factors for analysis were average air temperature, average relative humidity, ranges of daily air temperature, relative humidity, and wind speed. During the period, th daily average air temperature was $7~20^{\circ}C$ with the diurnal air temperature($7~20^{\circ}C$) and nocturnal air temperature($0~-2^{\circ}C$). The relative humidity ranged between 50 and 70% with the range of daily relative humidity(40~60%). Wind velocity was 1~4m.$s^{-1}$, From the results, it is concluded that the growing environmental conditions for high-quality oak mushroom differed from the optimum conditions for the high productivity of oak mushroom; environmental conditions such as wide ranges of air temperature and relative humidity, low humidity and wind speed might affect the emergence of high-quality oak mushroom.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.12-17
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• 2017

In this paper, causes of wear on high pressure seals for suspension are analyzed, and the result of reproduction test and verification on improved design are described. First, by performing the observation of worn surfaces and its failure analysis, the primary cause of wear on the seals are analyzed. The result of analysis shows that the main failure mechanism of wear is a fatigue wear, and test criteria for failure reproduction are set up with consideration for frequency condition, surface roughness and pressure. Durability comparison test on the condition of low amplitude and high frequency is carried out. And, it is found that the durability of wear on seals by increasing hardness of cylinder and managing for surface roughness is enhanced.

• Journal of radiological science and technology
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• v.11 no.1
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• pp.33-41
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• 1988

This study was measured the radiation-induced current - X-ray dose, dose rate, X-ray quality, time, temperature, electric field characteristics and the dependence of gap length in insulating oil under of D.C. Voltage before, during and after X-ray irradiation. The obtained results can be summarized as following. 1. The radiation - induced current is more the dependence of X-ray quality (tube voltage) than quantity (tube current), the dependence of quantity is appeared at the high than low X-.ay tube voltage. 2. The dependence of dose rate is appeared at the more dose rate, and ${\triangle}\;=\;0.64{\sim}0.74$. 3. The higher temperature of insulating oil and X-ray tube voltage (X-ray quality) is increased, at the low electric field, the more radiation-induced current. 4. $G_{eq}-G_{o}(={\triangle}G)$ is increased at the low than high temperature, high than low X-ray quality. 5. The dependence of temperature is appeared before than during X-ray irradiation. 6. The RIC saturation region is appeared at the high than low insulating oil temperature during (1000 V/cm above) than before (4000 V/cm above) X-ray irradiation.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.79-84
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• 2016

A kimchi container actively controlling $CO_2$ concentration by timely flushing of $CO_2$ gas was structured and tested in its capability and effectiveness because high $CO_2$ concentration enhances the sensory flavor of the product. The inlet and outlet valves of $CO_2$ gas were programmed to open and close allowing synchronous vent/$CO_2$ flush according to the requirements of its dissolution in the contained kimchi. During the chilled storage, the headspace of container could be maintained at desired high $CO_2$ concentration providing the preferred kimchi in sensory quality compared to control of the conventional container. However, there was no significant difference between the high $CO_2$ container and control (container simply closed with air) in kimchi quality attributes of pH, titratable acidity, total viable bacterial count, Lactobacillus sp. count and Leuconostoc sp. count. The flow rate and time interval of $CO_2$ flushing need to be adjusted considering the kimchi amount, headspace volume and ripening time. The designed system has potential to be applied in refrigerator appliances in homes and food service industry.

• Journal of the Korean Society of Costume
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• v.66 no.2
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• pp.1-14
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• 2016

This study was intended to investigate the influences that consumer's price sensitivity, bundle discount type, and price level of the male cosmetics have on consumer attitude. The design of this research was comprised of $2{\times}2{\times}2$ mixed design studies. The first element was high price sensitivity vs. low sensitivity, the second element was the bundle discount type (mixed leader vs. mixed-joint), and the third element was the price level of male cosmetics (high-price brand vs. low-price brand). The results of this study showed that price sensitivity, bundle discount type and price level of male cosmetic had a statistically significant interaction effect on the consumer's quality perception. The quality perception of low-cost brands for high price sensitivity/mixed-joint bundle group was low. The quality perception of low-cost brands for mixed-leader bundled groups did not change significantly even when the price sensitivity became higher. However, it can be seen as the same result that the overall value is higher when suggested the price information in Mixed-leader bundle than Mixed-joint bundle. In particular, this study suggests that price information should be presented in mixed-leader bundles for high price sensitivity and low cast brands.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.271-281
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• 1999

The cost of production of high quality pork is compensated by high returns, but constraints by the market are increasing. A few opportunities to maintain and improve pork quality by dietary means are presented. The healthy value of pork is a prerequisite. A careful control of suppliers and preservation of feeds are essential to protect pork against presence of contaminants from the feed. The feeding level and some dietary components modify the partition of the dietary energy into different pig tissues and chemical components of pork, affecting the hygienic and nutritional value, tenderness and taste. It is difficult to transfer a nutrient from the diet to pork, if the requirements. for growth are satisfied. Fatty acids and Vitamin E are the most studied exceptions. There is some evidence that iron and selenium contents can be affected too. Varying the content of a nutrient frequently changes sensorial and technological properties of pork. The addition of oils improves the acidic profile of depot fats, but the effect on phospholipid composition is not well studied and negative effects on oxidability and consistency of meat products are observed. Vitamin E can improve many healthy and sensorial characteristics, but its effect is clearer when the meat is stressed or manipulated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.90.2-90.2
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• 2012

Graphene has recently attracted significant attention because of its unique optical and electrical properties. For practical device applications, special attention has to be paid to the synthesis of high-quality graphene on large-area substrates. Graphene has been synthesized by eloborated mechanical exfoliation of highly oriented pyrolytic graphite, chemical reduction of exfoliated grahene oxide, thermal decomposition of silicon carbide, and chemical vapor deposition (CVD) on Ni or Cu substrates. Among these techniques, CVD is superior to the others from the perspective of technological applications because of its possibility to produce a large size graphene. PECVD has been demonstrated to be successful in synthesizing various carbon nanostructures, such as carbon nanotubes and nanosheets. Compared with thermal CVD, PECVD possesses a unique advantage of additional high-density reactive gas atoms and radicals, facilitating low-temperature, rapid, and controllable synthesis. In the current study, we report results in synthesizing of high-quality graphene films on a Ni films at low temperature. Controllable synthesis of quality graphene on Cu foil through inductively-coupled plasma CVD (ICPCVD), in which the surface chemistry is significantly different from that of conventional thermal CVD, was also discussed.

• Progress in Superconductivity and Cryogenics
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• v.16 no.4
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• pp.26-30
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• 2014

We investigate the upper critical field anisotropy ${\Gamma}_H$ and the magnetic penetration depth anisotropy ${\Gamma}_{\lambda}$ of a high-quality $FeSe_{1-x}$ single crystal using angular dependent resistivity and torque magnetometry up to 14 T. High quality single crystals of $FeSe_{1-x}$ were successfully grown using $KCl-AlCl_3$ flux method, which shows a sharp superconducting transition at $T_C{\sim}9K$ and a high residual resistivity ratio of ~ 25. We found that the anisotropy ${\Gamma}_H$ near $T_C$ is a factor of two larger than found in the poor-quality crystals, indicating anisotropic 3D superconductivity of $FeSe_{1-x}$. Similar to the 1111-type Fe pnictides, the anisotropies ${\Gamma}_{\lambda}$ and ${\Gamma}_H$ show distinct temperature dependence; ${\Gamma}_H$ decreases but ${\Gamma}_{\lambda}$ increases with lowering temperature. These behaviors can be attributed to multi-band superconductivity, but different from the case of $MgB_2$. Our findings suggest that the opposite temperature dependence of ${\Gamma}_{\lambda}$ and ${\Gamma}_H$ is the common properties of Fe-based superconductors.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.10
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• pp.840-846
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• 2000

In this work, small-size, high-performance solenoid-type RF chip inductors utilizing a low-loss Al$_2$O$_3$core material were investigated. The size of the chip inductors fabricated in this work were 15$\times$10$\times$0.7㎣, 2.1$\times$1.5$\times$10㎣, and 2.4$\times$2.0$\times$1.4㎣ and copper (Cu) wire with 40 ㎛ diameter was used as the coils. High frequency characteristics of the inductance, quality factor, and impedance of developed inductors were measured suing an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). It was observed that the developed inductors with the number of turns of 7 have the inductance of 33 to 100nH and exhibit the self-resonant frequency (SRF) of .26 to 1.1 GHz. The SRF of inductors decreases with increasing the inductance and the inductors have the quality factor of 60 to 80 in the frequency range of 300 MHz to 1.1 GHz. In this study, small-size solenoid-type RF chip inductors with high inductance and high quality factor were fabricated successfully. It is suggested that the thin film-type inductor is necessary to fabricate the smaller size inductors at the expence of inductance and quality factor values.