• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.21-27
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• 2019

Recently, embedded systems have been introduced in various fields such as smart factories, industrial drones, and medical robots. Since sensor data collection and IoT functions for machine learning and big data processing are essential in embedded systems, it is essential to port the operating system that is suitable for the function requirements. However, in embedded systems, it is necessary to separate the hard real-time system, which must process within a fixed time according to service characteristics, and the flexible real-time system, which is more flexible in processing time. It is difficult to port the operating system to a low-performance embedded device such as 8BIT MCU to perform simultaneous real-time. When porting a real-time OS (RTOS) to a low-specification MCU and performing a number of tasks, the performance of the real-time and general processing greatly deteriorates, causing a problem of re-designing the hardware and software if a hard real-time system is required for an operating system ported to a low-performance MCU such as an 8BIT MCU. Research on the technology that can process real-time processing system requirements on RTOS (ported in low-performance MCU) is needed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.311-320
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• 2019

This study aimed to optimize mixing conditions (adding amount of squid skin and sea tangle Saccharina japonica) for concentrates of octopus Octopus vulgaris cooking effluent (COCE) and roasting conditions (temperature and time) of seasoned Laver Pyropia yezoensis with concentrates of octopus cooking effluent (SL-COCE) using response surface methodology (RSM). The results of RSM program for COCE showed that the optimum independent variables ($X_1$, squid skin amount; $X_2$, sea tangle amount) based on the dependent variables ($Y_1$, odor intensity; $Y_2$, amino-N content; $Y_3$, sensory overall acceptance) for high-quality COCE were 0.53% (w/w) for $X_1$ and 0.48% (w/w) for $X_2$ for uncoded values. The results of the RSM program for SL-COCE showed that the optimum independent variables ($X_1$, roasted temp.; $X_2$, roasted time) based on the dependent variables ($Y_1$, burnt odor intensity; $Y_2$, water activity; $Y_3$, sensory overall acceptance) for high-quality SL-COCE were $344^{\circ}C$ for $X_1$ and 8 sec for $X_2$ for uncoded values. The SL-COCE prepared under optimum procedure was superior in sensory overall acceptance to commercial seasoned laver.

• The Journal of Information Systems
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• v.30 no.4
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• pp.21-42
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• 2021

Purpose In order for companies to continue to grow, they should properly manage human resources, which are the core of corporate competitiveness. Employee turnover means the loss of talent in the workforce. When an employee voluntarily leaves his or her company, it will lose hiring and training cost and lead to the withdrawal of key personnel and new costs to train a new employee. From an employee's viewpoint, moving to another company is also risky because it can be time consuming and costly. Therefore, in order to reduce the social and economic costs caused by employee turnover, it is necessary to accurately predict employee turnover intention, identify the factors affecting employee turnover, and manage them appropriately in the company. Design/methodology/approach Prior studies have mainly used logistic regression and decision trees, which have explanatory power but poor predictive accuracy. In order to develop a more accurate prediction model, XGBoost is proposed as the classification technique. Then, to compensate for the lack of explainability, SHAP, one of the XAI techniques, is applied. As a result, the prediction accuracy of the proposed model is improved compared to the conventional methods such as LOGIT and Decision Trees. By applying SHAP to the proposed model, the factors affecting the overall employee turnover intention as well as a specific sample's turnover intention are identified. Findings Experimental results show that the prediction accuracy of XGBoost is superior to that of logistic regression and decision trees. Using SHAP, we find that jobseeking, annuity, eng_test, comm_temp, seti_dev, seti_money, equl_ablt, and sati_safe significantly affect overall employee turnover intention. In addition, it is confirmed that the factors affecting an individual's turnover intention are more diverse. Our research findings imply that companies should adopt a personalized approach for each employee in order to effectively prevent his or her turnover.

• Composites Research
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• v.35 no.5
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• pp.328-333
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• 2022

In this study, the fabrication conditions of CFRP rebar were controlled to derive the correlation between flexural strength and pore characteristics. The fabrication conditions of CFRP rebar were adjusted for presence or absence of rib, resin temperature, and curing furnace temperature. Flexural strength and pore characteristics of fabricated CFRP rebar were analyzed. The flexural strength of CFRP rebar was changed depending on the fabrication condition, such as the presence or absence of rib, the resin temperature, and the curing furnace temperature. It was confirmed that the flexural strength of CFRP rebar was significantly lowered when the rib was not wound. As a result of Nano X-ray CT analysis, the max. pore diameter was shown in CFRP rebar prepared at a resin temperature of 60℃. According to optical microscopic analysis, the maximum porosity was 6.89% in No. 1, and the minimum porosity was 2.88% in No. 7. The correlation coefficient between porosity used optical microscopy and flexural strength was -0.64, which was higher than the correlation coefficient between porosity or pore size used Nano X-ray CT and flexural strength.

• The Journal of Advanced Prosthodontics
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• v.15 no.2
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• pp.63-71
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• 2023

PURPOSE. The aim of this study was to assess the effect of hemispherical dimple structures on the retention of cobalt-chromium (Co-Cr) crowns cemented to titanium abutments, with different heights and numbers of dimples on the axial walls. MATERIALS AND METHODS. 3.0-mm and 6.0-mm abutments (N = 180) and Co-Cr crowns were prepared. The experimental groups were divided into two and four dimple groups. The crowns were cemented by TempBond and PANAVIA F 2.0 cements. The retention forces were measured after thermal treatments. A two-way Analysis of Variance (ANOVA) and post-hoc Tukey HSD test were conducted to analyze change in retention forces by use of dimples between groups, as well as t test for the effect of abutment height change (α = .05). RESULTS. Results of the two-way ANOVA showed a statistically significant difference in retention force due to the use of dimples, regardless of the types of cements used (P < .001). A significantly higher mean retention forces were observed in the groups with dimples than in the control group, using the post hoc Tukey HSD test (P < .001). Results of t test displayed a statistically significant increase in the retention force with 6.0-mm abutments compared with 3.0-mm abutments (P < .001). The groups without dimples revealed adhesive failure of cements, while the groups with dimples showed mixed failure of cements. CONCLUSION. Use of hemispherical dimples was effective for increasing retention forces of cemented crowns.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.185-199
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• 2023

This study aimed to predict the effects of water ecology on the supply of hydrothermal energy to model a housing complex in Eco Delta Smart Village in Busan. Based on the results, engineering measures were recommended to minimize problems due to possible temperature variations on the supply of hydrothermal energy from the river. The current distribution of fish, benthic macroinvertebrates, and phytoplankton in the Pyeonggang Stream was monitored to determine their effects on water ecology. In the research area, five species and three families of fish were observed. The dominant species was Lepomis macrochirus, and the subdominant species was Carassius auratus. Twenty-five species and 21 families of benthic macroinvertebrates were found. The distribution of aquatic insects was poor in this area. The dominant species were Chironomidae sp., Lymnaea auricularia, Appasus japonicus, and Caridina denticulata denticulata in February, May, July, and October. Dominant phytoplankton were Aulacoseira ambigua and Nitzschia palea in February and May. Microcystis sp. was dominant in July and October. The health of the ecology the Pyeonggang Stream was assessed as D (bad) according to the benthic macroinvertebrate index (BMI). Shifts in the location of the discharge point 150 m downstream from intake points and discharge through embedded rock layer after adding equal amounts of stream water as was taken at the beginning were suggested to minimize water temperature variations due to the application of hydrothermal energy. When the scenario (i.e., quantity of water intake and dilution water, 1,600 m³/d and water temp. difference ±5 ℃) was realized, variations in water temperature were assessed at -0.19 ℃ and 0.59 ℃ during cooling and heating, respectively, at a point 10 m downstream. Water temperatures recorded at -0.20 ℃ and 0.68 ℃ during cooling and heating, respectively, at a point 10 m upstream. All stream water temperatures after the application of hydrothermal energy recovered within 24 hours. Future work on the long-term monitoring of ecosystems is suggested, particularly to analyze the influence of the water environment on hydrothermal energy supply operations.

• Journal of Mushroom
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• v.11 no.1
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• pp.36-40
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• 2013

Armillaria gallica was ecologically surveyed to investigate its relationship with Gastrodia elata in cultivation areas of Korea in 2012. In the observation made around October 17 in the area of Namyangju (Gyeonggi), Sangju (Gyeongbuk) and Gimcheon (Gyeongbuk) in Korea, the fruit bodies of A. gallica were consistently found near the cultivation areas of Gastrodia elata across these cultivation areas. Since the temperature and rainfall have been considered as important factors of fruiting of A. gallica, we checked the temperature and rainfall around two weeks ago of mushroom fruiting. The average temperature of all cultivation areas was $9.9{\sim}17.5^{\circ}C$ (the lowest temp.: $3{\sim}23^{\circ}C$, the highest temp.: $15{\sim}26^{\circ}C$) and the annual rainfall was 0.5~1.0mm on October 10 which can be compared to 2.5~4.5mm on October 17. Fruiting bodies were generally developed at weedy field in which G. elata were cultivated five years ago. The field was inclined 15 degrees, east-facing and consists of loam. The fruit bodies were formed on both sides of a small ditch between the Gastrodia elata cultivation fields and neighboring fields, and the areas were common weeds and moisture at all times. The fruiting bodies were growing above the soil rather than oak wood. Gregarious, but also occurs to 1-5 fruiting bodies occur sporadically. Results observed in detail the growing areas, some fruit bodies were developed along the black and thick rhizomorph formation.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.753-759
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• 2016

The processing properties of spent hen and broiler chicken were investigated before and after treatment to improve texture characteristics. Each treatment consisted steaming (S) with $85^{\circ}C$ for 20 min, Pulsed Electric Field (PEF) with 1.5 KV/cm for 4 sec, and Super Heated Steam (SH) with an oven temp. of $300^{\circ}C$, a steam temp. of $350^{\circ}C$ for 8 min. The yield of spent hen and broiler were 66.85% and 63.80% respectively in the control, but decreased in every treatment was lowest at 61.05% in the PEF treatment (p<0.05). In the color test, L value decreased, but the a and b values increased regardless of the species of spent hen or broiler. In the test of heating loss, the S treatment of spent hen had the highest result of 45.25% but lowest of 30.66% in the SH treatment of the broiler. When it was compared with various treatments, SH after PEF treatment showed the better result in terms of heating loss than the PEF or SH treatment respectively. In the test of texture, the broiler showed the lowest hardness of 5.57 kg in the SH (p<0.05). Otherwise, the spent hen resulted in 14.08 kg of hardness in steaming after PEF, but it improved significantly to 10.73 kg in SH after PEF. In the test of 9 scored sensory evaluation of overall palatability, 7.8 point was the best score with SH treatment in the broiler. The best score in spent hen was 6.3 point which was SH after PEF treatment. With this experiment, SH after PEF was the condition in the treatments to have the better texture of spent hen.

• Applied Biological Chemistry
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• v.18 no.1
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• pp.42-51
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• 1975

Penicillium sp I which produces a powerful hydrolysing enzyme was isolated from putrefid and dry Jerusalem artichoke medium. The strain was used to study on the optimum culture conditions for enzyme production. The results obtained are as follows: 1. Penicillium sp I was a vigorous strain to produce inulase. 2. The optimum culture conditions of the strain was examined in the Jerusalem artichoke extract medium and the synthetic medium. 3. Inulase productivity in the Jerusalem artichoke extract medium was higher than that of the synthetic medium. 4. The optimum culture period of the Jerusalem artichoke extract medium was four days, whereas that of the synthetic medium was five days. 5. The optimum temperature, pH and concentration in the Jerusalem artichoke extract medium were $30^{\circ}C$, 5.0 and 4.0% (W/V), respectively. Meanwhile, the optimum temperature, pH and concentration in the synthetic medium were $30{\sim}33^{\circ}C$, $5.0{\sim}6.0$, and $1.0{\sim}1.5%$ (W/V), respectively. 6. Corn steep liquor, peptone, $(NH_4)_2HPO_4,\;NH_4H_2PO_4,\;(NH_4)_2SO_4$, etc. were favorable as nitrogen sources. Of these, especially, Corn steep liquor and peptone as organic nitrogen sources caused an increase in inulase production in the synthetic medium. 7. All sugars except for inulin have no effect upon the inulase production. 8. KCl, $MgSO_4\;and\;FeSO_4$ were favourable mineral sources for inulase production.

• Culinary science and hospitality research
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• v.21 no.1
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• pp.281-296
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• 2015

This study performed to find proper temperature and improve texture and taste of pickle by considering physic-chemical characteristic and sensory evaluation. The basis temperature of the pickle was manufactured by 5 temperatures($95^{\circ}C$, $85^{\circ}C$, $75^{\circ}C$, $65^{\circ}C$, $5^{\circ}C$) at intervals of $10^{\circ}C$, and the dangerous Temp range was exempted during 12 days. Results showed that 3rd day at $95^{\circ}C$ was the best temperature for the quality specification of the pickle. In addition, between 6th to 12nd days at $85^{\circ}C$ and $95^{\circ}C$ appeared the most excellent preferences of the pickles. Thus, quality specifications showed different results by the date, and it appeared $95^{\circ}C>85^{\circ}C>75^{\circ}C>65^{\circ}C>5^{\circ}C$ in order. Furthermore, the liquid pickles at the temp of $95^{\circ}C{\sim}85^{\circ}C$ showed better texture and flavor of pickles as well as good preference. Based on these results, managers or administrators of foodservice business will be recognized the importance of temperature and storage period for salted pickles to improve its texture and taste along with improving quality and preference.