• Journal of the Korean Society for Heat Treatment
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• v.37 no.3
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• pp.103-113
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• 2024

Martensite volume fraction significantly affects the mechanical properties of alloy steels. Martensite start temperature (M_s), transformation temperature for martensite 50 vol.% (M₅₀), and transformation temperature for martensite 90 vol.% (M₉₀) are important transformation temperatures to control the martensite phase fraction. Several researchers proposed empirical equations and machine learning models to predict the Ms temperature. These numerical approaches can easily predict the Ms temperature without additional experiment and cost. However, to control martensite phase fraction more precisely, we need to reduce prediction error of the Ms model and propose prediction models for other martensite transformation temperatures (M₅₀, M₉₀). In the present study, machine learning model was applied to suggest the predictive model for the Ms, M50, M90 temperatures. To explain prediction mechanisms and suggest feature importance on martensite transformation temperature of machine learning models, the explainable artificial intelligence (XAI) is employed. Random forest regression (RFR) showed the best performance for predicting the Ms, M50, M90 temperatures using different machine learning models. The feature importance was proposed and the prediction mechanisms were discussed by XAI.

• Korea journal of population studies
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• v.22 no.2
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• pp.121-161
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• 1999

1997년 11월 대외지불 불능사태로 시작된 외환위기가 경제위기로 확산되면서 97년 4/4분기에는 2.5%에 불과하던 전북지역의 실업률은 99년 2월 8.4%로 피크를 이루었으나 그후로는 감소추세를 보이고 있다. 그렇지만 전북지역 노동시장의 전반적 고용동향을 살펴보면 실업률 통계로는 파악되지 않지만 실질적으로 준실업상태에 있는 실망노동자와 불완전취업자의 증가가 심각한 것으로 드러났다. 그리고 산업별 취업자 구조의 변화를 살펴보면 제조업과 건설업의 취업자 감소가 두드러졌으며, 농업부문이나 생계형 서비스업은 실업대란 시대에 완충역할을 해줄 것이라는 기대와는 달리 고용흡수력이 예상보다 훨씬 적은 것으로 드러났다. 취업과 실업 및 비경제활동 사이의 노동력 전이률을 살펴보면 남성과 핵심연령층에서는 취업정착률이 높지만 일단 실업자가 되면 실업으로부터의 탈출률이 낮은 것으로 드러났다. 반면에 여성의 경우에는 실망노동자(discouraged sorkers)효과로 인하여 실업률은 낮고 비경제활동으로의 이동이 크게 나타났다. 그리고 실업이나 비경활상태로부터의 (재)취업시에는 압도적으로 임시고/일고로의 취업이 많아서 98년 하반기 이후 전북지역에서 창출된 일자리가 주로 임시고/일고 위주로 이루어져 있음을 극명하게 보여준다. 한편 여성실업자의 경우 50%이상이 생계주책임자이며, 특히 여성가장 실업자의 경우에는 90%이상이 생계책임자이나 그들 대부분이 빈곤선이하에서 생활하고 있다. 그리고 전북지역에서는 전국수준에 비해서 장기실업률이 다소 높게 나타났다. 저학력층과 고령층, 생산직, 임시고일고등의 비정규직 실업자들의 구직기간이 긴 것으로 나타났다. 실업이 장기화되면 전반적으로 기간의존성효과(duration dependence effect)나 이질성효과(heterogeneity effect)로 인하여 재취업의 가능성은 더욱 떨어진다. 생산적복지(workfare)가 그 이름에 값하는 것이기 위해서는 시장경쟁력이 약한 취약계층에 대해서 직업훈련과 취업알선 및 채용장려, 공공근로 등의 제반 정책들이 가구되어야 할 것이다.

• FLOWER RESEARCH JOURNAL
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• v.16 no.4
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• pp.255-259
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• 2008

This study was conducted to investigate the effect of ridge height (10 cm, 20 cm, 30 cm, and 40 cm) on the soil physical property, the growth and flowering characteristics of Gypsophila paniculata (cv 'Bristol Fairy') in the subalpine area. As ridge height got higher, the daily soil temperature, the soil moisture content, soil hardness, bulk density, and solid phase ratio were decreased, but porosity ratio was a little increased. In summer and autumn cultivation the blooming of ridge height 30 cm and 40 cm was slightly delayed, but their root activity, cut flower width, and yield were better than those of 10 to 20 cm ridges. And the mortality ratio of plants, rosette formation rate, and nonpaniculata inflorescence rate became lower.

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.185-189
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• 2009

This study was carried out to investigate the effect of shading (50% or not) and pruning height (3cm, 6cm, and 9cm) of remained above-ground plant part on shoot emergence aspect, mortality rate, flowering and cut flower characteristics of two years old Gypsophila paniculata plants. Days to shoot emergence (80%) advanced, emerged shoot number increased and mortality rate surveyed on late October decreased in 50% shading treatment. In addition to, mortality rate decreased, as above-ground plant part was highly pruned. Blooming was earlier with highly pruning the remained above-ground pan and under non-shading condition than shading. Growth traits such flower stalk length, primary branches number, stem diameter, and cut flower yield were the best and also non-particulate rate and rosette formation rate were the lowest in pruning height of 9cm under non-shading condition.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.377-389
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• 2021

This paper presents a framework design of a digital twin system for a vertical smart farm. In this paper, a framework of digital twin systems establishes three factors: 1) Client 2) IoT gateway, and 3) Server. Especially, IoT gateway was developed using the Eclipse Ditto, which has been commonly used as the standard open hardware platform for digital twin. In particular, each factor is communicating with the client, IoT gateway, and server by defining the message sequence such as initialization and data transmission. In this paper, we describe the digital twin technology trend and major platform. The proposed design has been tested in a testbed of the lab-scale vertical smart-farm. The sensor data is received from 1 Jan to 31 Dec 2020. In this paper, a prototype digital twin system that collects environment and control data through a raspberry pi in a plant factory and visualizes it in a virtual environment was developed.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.605-614
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• 2020

This study was conducted to investigate the effects of TMR on in vitro rumen fermentation and methane production of goat with different forage sources. The experiment was arranged 4×2 factorial design. The different forage sources were rice straw (RS), Italian rye grass (IR), timothy (TI) and alfalfa (AL), respectively. There were two different forage : concentrate ratios such as 20:80 (20) and 50:50 (50), respectively. Therefore, totally 8 treatments were used: 1) RS20, 2) RS50, 3) IR20, 4) IR50, 5) TI20, 6) TI50, 7) AL20, and 8) AL50, respectively. The rumen fluid of goat was collected from the slaughterhouse. For fermentation parameters, ruminal pH, total gas, methane, hydrogen, ammonia nitrogen, and volatile fatty acid were determined. The pH values were within an optimal range across all treatments. Total gas productions at TI20 and AL50 were significantly greater than others (p<0.05). Methane production was significantly lower in TI and AL compared with other treatments (p<0.05). The relatively high dietary NDF content in treatments showed significantly lower methane production (p<0.05). Significant alterations treatments were detected at ammonia nitrogen concentration according to the ratio of forage : concentrate (p<0.05). AL treatment showed greater total volatile fatty acid production compared with other treatments (p<0.05). Therefore, the present study suggests that both Timothy and Alfalfa could be recommendable forage sources for goat based on results with volatile fatty acid as an energy source and methane as an index for energy loss and environmental issues. Also, the 50:50 (forage : concentrate) ratio would prefer to 20:80.

• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.137-148
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• 2021

The present study investigated the effect of average daily gain (ADG) on carcass traits of Hanwoo steers. A total of 233 heads of Hanwoo steer slaughtered from 2017 to 2020 were employed in the analysis. Their body weight profiles during feedlot and carcass traits were used. The entire feedlot period is split into two periods. ADG during the first period (ADG1) was then defined as an independent variable in statistical analysis. In the meantime, it was examined that how the cutoff month for the period split altered the significance of the effect of ADG1 on carcass traits. Subsequently, steers were assigned to two groups (High vs. Low) based on the median of total ADG1, and we compared the carcass traits of each group using a linear mixed model. ADG1 during 10 to 23 months showed a significant effect on all carcass traits except the marbling score. ADG1 significantly influenced carcass weight and eye muscle area of Hanwoo steers. And it was found that greater ADG1 could get greater carcass weight and eye muscle area (p<0.001). The result of this study provides preliminary information for the target month in the calculation of ADG1 mostly influencing carcass performance, and feeding strategy of Hanwoo steer in terms of sustainability.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.627-641
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• 2020

Intensive farming methods that do not guarantee animal welfare can induce stress in pigs. Stress, in turn, can reduce their disease resistance and influence their hormones and metabolites in such a manner that productivity is negatively affected. This study was conducted to compare the stress related factors and blood characteristics of pigs raised on conventional farms and those raised on animal welfare farms. We measured the levels of cortisol, epinephrine and norepinephrine, biochemical parameters in blood and glycogen, L-lactate and heat shock protein 70 (HSP70) in muscle, as physiological markers of indicating the stress in conventional farm pigs (Control, n=10) and animal welfare farm pigs (Welfare, n=10). We found that there was a significant difference in the albumin-globulin ratio (A/G ratio), as well as the albumin (ALB), blood urea nitrogen (BUN) and aspartate aminotransferase (AST) levels between the two farms. Epinephrine was significantly higher in conventional farm, while level of norepinephrine was higher in animal welfare farm. There was no significant difference in cortisol, which is known as a stress hormone, across the two groups of farms. Muscular glycogen content was significantly high in animal welfare farm pigs. While L-lactate tended to be low in the animal welfare farm pigs, the difference between them and the conventional farm cohorts was not significant. HSP70 showed high levels of expression in conventional farm. Thus, we suggested that blood parameter results showed a stress response in the livers of conventional farm, and that catecholamine hormones, glycogen, L-lactate and HSP70 can be used as physiological factors of assessing animal welfare.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.567-572
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• 2018

Radiation therapy is one of the beneficial choices in the treatment of cancer. This is a comparison of TPS(Treatment Planning System) and GEANT4-DICOM, which should be preceded by the best radiation therapy. A treatment plan for prostate cancer was established with Eclipse and the point doses 366.1 cGy, 189.1 cGy, 213.4 cGy, 127 cGy, 105.7 cGy of any five prostate, bladder, rectum, right femoral head and left femoral head were identified. GEANT4-DICOM simulation showed that the results of Eclipse and ${\pm}2%$ dose error were confirmed. The monthly X-ray output agreement management value recommended by TG-142 is ${\pm}2%$, which means that the experimental results can be meaningful. In conclusion, GEANT4-DICOM is an infinite way to obtain more extended dose information once the time constraints are overcome in the simulation.

• Journal of Korean Society of Rural Planning
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• v.24 no.4
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• pp.47-55
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• 2018

Currently in the drought evaluation, which is a supplier-oriented standard that applies storage rates of reservoirs, evaluation for users that use agricultural water is not done. Therefore, this study established drought evaluation items for drought evaluation based on farmers' judgement, conducted a survey on farmers and experts, compared and analyzed weighted value between two groups, and then classified the evaluation standards per each evaluation item. The agricultural drought evaluation items are 5 major items of water supply lapse rate, agricultural weather, agricultural irrigation facility, crop and soil, and 12 subsections for regional characteristics and opinions of consumers that use water to be reflected. The result of analyzing weighted value of farmers and experts' major items shows that farmers is agricultural irrigation facility(0.219), water supply lapse rate(0.211), agricultural weather(0.204), crop(0.183) and soil(0.183). Experts is agricultural weather(0.297), agricultural irrigation facility(0.202), water supply lapse rate(0.189), crop(0.162) and soil(0.150), which displays difference between the two groups. The agricultural drought criteria standards are established based on precedent studies and cases, and grades of evaluation items are 1st grade(extreme stage), 2nd grade(warning stage), 3rd grade(alert stage) and 4th grade(attention stage). The above analysis per each consumer-oriented agricultural drought evaluation item and the analysis on the standards of evaluation grades are expected to be used as a basic resource for establishing agriculture drought policy and selecting drought area in the future.