• Journal of Mushroom
• /
• v.19 no.3
• /
• pp.216-224
• /
• 2021

This study analyzed food component characteristics and antioxidant activities in five kinds of domestic commercial shiitake mushrooms (Lentinula edodes). Moisture content (79.17-82.90 g/100 g) showed little difference, but there was a significant difference in crude protein content. Total mineral content showed a significant difference, and potassium (K) content was the highest. Total and essential amino acid contents were higher in mushroom A than in the other samples. Nonetheless, the ratios of essential amino acids, aspartic acid, and glutamic acid to total amino acids were similar in all samples. 𝛽-Glucan content was in the range of 10.28-5.68 g/100 g, exhibiting a significant difference. The color intensity and overall texture of the mushrooms showed no remarkable difference. Total phenol and flavonoid contents were in the range of 19.92-30.77 mg/100 g and 6.95-10.39 mg/100 g, respectively; the ratio of flavonoids to total phenols ranged from 31.53% to 38.21%. DPPH and ABTS radical scavenging activities were 74.92-79.04% and 80.47-84.97%, respectively, and showed little difference. However, the reducing power varied between 195.23 𝜇M and 317.85 𝜇M, displaying a significant difference in all samples. Therefore, this study observed similar trends in the food component characteristics and antioxidant activities of domestic commercial shiitake mushrooms.

• Journal of Breast Disease
• /
• v.6 no.2
• /
• pp.52-59
• /
• 2018

Purpose: This study aimed to determine whether clinicopathological factors are potentially associated with successful breast-conserving surgery (BCS) after neoadjuvant chemotherapy (NAC) and develop a nomogram for predicting successful BCS candidates, focusing on those who are diagnosed with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative tumors during the pre-NAC period. Methods: The training cohort included 239 patients with an HR-positive, HER2-negative tumor (${\geq}3cm$), and all of these patients had received NAC. Patients were excluded if they met any of the following criteria: diffuse, suspicious, malignant microcalcification (extent >4 cm); multicentric or multifocal breast cancer; inflammatory breast cancer; distant metastases at the time of diagnosis; excisional biopsy prior to NAC; and bilateral breast cancer. Multivariate logistic regression analysis was conducted to evaluate the possible predictors of BCS eligibility after NAC, and the regression model was used to develop the predicting nomogram. This nomogram was built using the training cohort (n=239) and was later validated with an independent validation cohort (n=123). Results: Small tumor size (p<0.001) at initial diagnosis, long distance from the nipple (p=0.002), high body mass index (p=0.001), and weak positivity for progesterone receptor (p=0.037) were found to be four independent predictors of an increased probability of BCS after NAC; further, these variables were used as covariates in developing the nomogram. For the training and validation cohorts, the areas under the receiver operating characteristic curve were 0.833 and 0.786, respectively; these values demonstrate the potential predictive power of this nomogram. Conclusion: This study established a new nomogram to predict successful BCS in patients with HR-positive, HER2-negative breast cancer. Given that chemotherapy is an option with unreliable outcomes for this subtype, this nomogram may be used to select patients for NAC followed by successful BCS.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.4
• /
• pp.613-618
• /
• 2019

The flow-induced vibration in a heat exchanger may cause the damage to piping. Therefore, it is necessary to establish the flow induced vibration characteristics for the structural stability of a heat exchanger. The purpose of this study was to compare the generation, development, and separation characteristics of a vortex around a circular tube with respect to time when the flow velocity of the inlet was fluctuating constantly and periodically. The time characteristics of lift and drag and the PSD characteristics were also investigated. In the case of a constant inlet flow velocity, the well-known Kalman vorticity distribution was shown. The vortex generation, growth, and separation were also observed alternately at the upper and lower sides of the tube. In the case of periodic inlet flow velocity, the vortex occurred simultaneously in the upper and lower sides of the tube. In the case of constant inlet flow velocity, the magnitude of the lift PSD was 500 times larger than that of drag. The frequency was 31.15 Hz and that of drag was doubled at 62.3 Hz. In case of a periodic inlet flow velocity, the PSD of the drag was approximately 500 times larger than that of lift. The frequency was 15.57 Hz, which was the same as the inlet-flow velocity frequency. In addition, the frequency of lift was 31.15 Hz, which was the same Karman vortex frequency.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.5
• /
• pp.364-370
• /
• 2019

In this paper, an individual blade control (IBC) methodology is applied to find the best input scenario for vibratory hub loads reduction of XH-59A co-axial rotorcraft in high speed flight. A comprehensive aeromechanics analysis code CAMRAD II is employed to analyze the aircraft. A parametric study is conducted for optimum IBC inputs leading to the maximum vibration reduction. Numerical results demonstrate that up to 50% reduction in the hub vibration index is obtained for an IBC input at 3/rev frequency with the amplitude and phase angle of 0.5 deg. and 300 deg., respectively. The upper rotor exhibits as much as 6% more vibration reduction as compared to that of the lower rotor due to a clean inflow characteristic of the rotor. It is found that further vibration reduction gain is reached for IBC inputs with advancing-side only control. The hub vibration becomes reduced by up to 17% in reference to that with full rotor disk control. It is noted that the additional gain is obtained with significantly less power input with the advancing-side only control.

• (The)Study of the Eastern Classic
• /
• no.36
• /
• pp.333-374
• /
• 2009

Korean traditional education emphasizes moral education than any other country or culture. Education is recognized as practical task for self-realization and self-transcendence in traditional Confucian community. This study starts from two questions. First, how moral education in Korea from late in the 19th, when the modernized schooling started, to now can be classified according to social and political circumstances? Second, what is the main issue of moral education in the progress of Korean education after independence from Japanese imperialism? Especially, this study focuses on reflecting and reviewing these issues by context of Eastern moral education. After late in the 19th century, moral education in Korea is divided into three types: "Education for loyalty and filial piety and Moral cultivation", "Citizenship education and Education for anti-communism", and "Moral education and Character education". This study mainly insists these types of moral education distort the sprit by political interests rather than inherit and develop sprit or basic value of moral education. Furthermore, this study discusses characteristic of moral education and way to improve based on important two issues in Korean society; "Nationalism in moral education" and "Western biased education" Making individual's free will into group consciousness in accordance with political power group's interests rather than developing moral community based on each one's character building, nationalism in moral education deepens self-alienation. Western biased education makes self-negation as it considers western as core, and Korea and other traditional ideas as side. This study emphasizes reanalysis Eastern moral education and need effort for understanding of Eastern moral education to overcome Western biased education in Korean moral education.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.1
• /
• pp.43-56
• /
• 2012

Wireless sensor networks consist of numerous small-sized nodes equipped with limited computing power and storage as well as energy-limited disposable batteries. In this networks, nodes are deployed in a large given area and communicate with each other in short distances via wireless links. For energy efficient networks, dynamic clustering protocol is an effective technique to achieve prolonged network lifetime, scalability, and load balancing which are known as important requirements. this technique has a characteristic that sensing data which gathered by many nodes are aggregated by cluster head node. In the case of cluster head node is exposed by attacker, there is no guarantee of safe and stable network. Therefore, for secure communications in such a sensor network, it is important to be able to encrypt the messages transmitted by sensor nodes. Especially, cluster based sensor networks that are designed for energy efficient, strongly recommended suitable key management and authentication methods to guarantee optimal stability. To achieve secured network, we propose a key management scheme which is appropriate for hierarchical sensor networks. Proposed scheme is based on polynomial key pool pre-distribution scheme, and sustain a stable network through key authentication process.

• Nuclear Engineering and Technology
• /
• v.54 no.9
• /
• pp.3250-3259
• /
• 2022

A new approach to the use of rice straw as a difficult-to-recycle agricultural waste was proposed. Potassium aluminosilicate was obtained by spark plasma sintering as an effective material for subsequent immobilization of ¹³⁷Cs into a solid-state matrix. The sorption properties of potassium aluminosilicate to ¹³⁷Cs from aqueous solutions were studied. The effect of the synthesis temperature on the phase composition, microstructure, and rate of cesium leaching from samples obtained at 800-1000 ℃ and a pressure of 25 MPa was investigated. It was shown that the positive dynamics of compaction was characteristic of glass ceramics throughout the sintering. Glass ceramics RS-(K,Cs)AlSi₃O₈ obtained by the SPS method at 1000 ℃ for 5 min was characterized by a high density of ~2.62 g/cm³, Vickers hardness ~ 2.1 GPa, compressive strength ~231.3 MPa and the rate of cesium ions leaching of ~1.37 × 10^-7 g cm^-2·day^-1. The proposed approach makes it possible to safe dispose of rice straw and reduce emissions into the atmosphere of microdisperse amorphous silica, which is formed during its combustion and causes respiratory diseases, including cancer. In addition, the obtained is perspective to solve the problem of recycling long-lived ¹³⁷Cs radionuclides formed during the operation of nuclear power plants into solid-state matrices.

• Journal of Applied Biological Chemistry
• /
• v.65 no.4
• /
• pp.375-381
• /
• 2022

The purpose of this study was to evaluate the quality characteristics and biological activities of Rosa multiflora Thunberg fruit extracts fermented with Lactobacillus plantarum based on fermentation period of 0, 24, 48, and 72 h. The study showed the pH of Rosa multiflora Thunberg fruit fermentation extracts have decreased as fermentation time increased, but the sugar content remained the same. The total acid content increased as the fermentation time increased. The viable cell count was at highest at 24 h (8.59 log CFU/mL) of fermentation, and the viable cell count decreased as the fermentation time increased. The total polyphenol content (14.85 mg GAE/g), total flavonoid content (6.74 mg RE/g), 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, ABTS⁺ radical scavenging activity, reducing power, α-glucosidase and α-amylase inhibitory activity were highest at 24 h of fermentation. Therefore, the study proved fermentation of Rosa multiflora Thunberg fruit with lactic acid increases physiological activity compared to nonfermented Rosa multiflora Thunberg fruit. Also the 24 h of fermentation had the highest activity, confirming the possibility of future use as a functional food material.

• Journal of Industrial Convergence
• /
• v.20 no.12
• /
• pp.245-250
• /
• 2022

This study aims to identify the factors that affect the satisfaction of practice among nursing students who participated after replacing it with on-campus practice in a situation where practice was not possible due to COVID-19. Data were collected from 144 nursing students who participated in the clinical practice alternative campus practice conducted from September 13 to December 3, 2021 at a university located in G province. Data analysis was analyzed by ANOVA, Pearson's correlation coefficient, and hierarchical multiple regression analysis. The subject's satisfaction with practice is a general characteristic, self-efficacy (r=.540, p=.000), self-leadership (r=.553, p=.000), and critical thinking ability (r=.382, p=.000). , there was a significant correlation between major satisfaction (r= .248, p=.003). Variables that affect the clinical performance of the subjects were self-efficacy 20.4% (𝛽=.266, p=.047), self-leadership 51.2% (𝛽=.271, p=.047), and satisfaction with practice The explanatory power of the variables was 33.8%. Therefore, it is necessary to develop and apply a curriculum that can increase self-leadership and self-efficacy in order to increase the satisfaction of nursing students' practice.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.25 no.2
• /
• pp.101-120
• /
• 2023

Electrical resistivity survey have been widely conducted at diverse scales, from a few centimeters for laboratory tests to kilometers for field tests. It measures electrical resistance through relationship of electric potential difference and current between two electrodes penetrated on the surface of medium, and eventually quantifies electrical resistivity known as inherent properties of the medium. In field or full-scale test, it assumes the electrodes as equivalent half-sphere electrodes that have a same surface area with different electrodes for ease of calculation because the contact area between electrode and medium is small and sufficient distance between two electrodes. However, small-scale laboratory test is significantly affected by the electrode geometries (penetrated depth, height, radius of electrode and distance between electrodes), which change the equipotential surface and electric current flow. Indeed, the electrode geometries may eventually cause a difference of electrical resistivity value. This study reviews the theoretical electrical resistance derived with various electrode geometries (half-sphere, cylinder, cylindrical with half-spherical tip, cylindrical with conical tip) and verifies the developed numerical module by comparing results with the theoretical electrical resistance. The distributions of electrical resistance around electrodes and among electrodes are analyzed. In addition, it is discussed how the electrical characteristic of cylindrical electrode with conical tip widely used in field test has effect on the electric current flow.