• Advances in concrete construction
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• v.14 no.5
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• pp.317-330
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• 2022

This paper investigated computationally and experimentally the interaction here between a notch as well as a micropore under uniaxial compression. Brazilian tensile strength, uniaxial tensile strength, as well as biaxial tensile strength are used to calibrate PFC2d at first. Then, uniaxial compression test was conducted which they included internal notch and micro pore. Experimental and numerical building of 9 models including notch and micro pore were conducted. Model dimensions of models are 10 cm × 10 cm × 5 cm. Joint length was 2 cm. Joints angles were 30°, 45° and 60°. The position of micro pore for all joint angles was 2cm upper than top of the joint, 2 cm upper than middle of joint and 2 cm upper than the joint lower tip, discreetly. The numerical model's dimensions were 5.4 cm × 10.8 cm. The fractures were 2 cm in length and had angularities of 30, 45, and 60 degrees. The pore had a diameter of 1 cm and was located at the top of the notch, 2 cm above the top, 2 cm above the middle, and 2 cm above the bottom tip of the joint. The uniaxial compression strength of the model material was 10 MPa. The local damping ratio was 0.7. At 0.016 mm per second, it loaded. The results show that failure pattern affects uniaxial compressive strength whereas notch orientation and pore condition impact failure pattern. From the notch tips, a two-wing fracture spreads almost parallel to the usual load until it unites with the sample edge. Additionally, two wing fractures start at the hole. Both of these cracks join the sample edge and one of them joins the notch. The number of wing cracks increased as the joint angle rose. There aren't many AE effects in the early phases of loading, but they quickly build up until the applied stress reaches its maximum. Each stress decrease was also followed by several AE effects. By raising the joint angularities from 30° to 60°, uniaxial strength was reduced. The failure strengths in both the numerical simulation and the actual test are quite similar.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.2
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• pp.64-67
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• 1980

Field experiments were conducted to determine the optimum harvesting time and to evaluate the effect of Diquat spray in late seeded sesame, cultivar 'Suweon 9'. Sesame seed yield reached a plateau from Sept. 18 harvest when seed number was maximum. Thousand seed wt. increased to Sept. 29 harvest. As harvesting was delayed moisture content of capsule decreased and capsule dehiscence increased. Capsule dehiscence did not start until its moisture content dropped below 70%. Optimum harvesting might begin from the time which moisture content of capsule dropped below 70%, leaf senescence reached upper node, and 50% of capsules lost green. About 5% increase in seed weight after defoliation was estimated to be translocation from capsule wall. Diquat spray with 0.3% and 0.5% (v/v) solution of commercial Reglone (20%in A.I.) decreased rapidly capsule moisture content and promoted seed shattering. Dehiscence in 90% capsules was noted at seven days after Diquat spray. Diquat spray as a harvest aid could accelerate sesame desiccation up to 2 wks from normal field condition.

• Journal of Korean Medical classics
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• v.13 no.1
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• pp.117-145
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• 2000

Tongmu I Je-ma(1837-1900) set up Sasang Constitutional Medicine(四象體質醫學), a medical theory that would be original in the Korean medical history through his book ${\ll}$Tang-uisusebowon(東醫壽世保元)${\gg}$. In this book, he writes that he found the clue to his sasang Constitution(四象體質) theory from ${\ll}$Hwangjenaegyong(黃帝內經)${\gg}$. But the main logic that gives shape to the Constitution(體質) theory is $s{\check{o}}ng-ch{\check{o}}ng$ theory(性情論) of Confucian. Therefore, Tongmu(東武)'s Constitution $s{\check{o}}ng-ch{\check{o}}ng$ theory(體質性情論) is fundamentally based on confucian thoughts. Kongmaeng(孔孟) saw $s{\check{o}}ng$(性) as a base for connecting the entire mankind to be united, and $ch{\check{o}}ng$(情) as a individual thing that can exalted differently according to one's state of mind. Chuja(朱子) weakene the human's active volition by dividing $s{\check{o}}ng$ and $ch{\check{o}}ng$ as ibal(理發) and kibal(氣發) and therefore describing mankind to be submitted to Heaven's will. On the other hand Yolgok(栗谷) generalized $s{\check{o}}ng-ch{\check{o}}ng$ in the active mind of man himself by saying that $s{\check{o}}ng$ is when i-ki(理氣) does not act as a bodily function of the mind and $ch{\check{o}}ng$ is when it does. Furthennore he emphasized man's activeness on pursuing good by saying that the division of good and bad does not start from the origin of motion but is divided by the condition of ki(氣) which leads motion. Tongmu, who was influenced by Yulgok linked both $s{\check{o}}ng$and $ch{\check{o}}ng$ through, happiness, anger, sadness, pleasure(喜怒哀樂), and saw $s{\check{o}}ng$ as the ability to recognize good which is in the kijil(氣質) formed from the integration of i-ki, and saw $ch{\check{o}}ng$ as $s{\check{o}}ng$ blurred by man's greed. In addition to this, he says that the direct connection between each person's divergence in $s{\check{o}}ng-ch{\check{o}}ng$ and the condition of Four-organ(四臟) which is ki, not the mind which is i(理) forms sasangch'ejirin(四象體質人). His theory that illness comes from the partiality of $s{\check{o}}ng-ch{\check{o}}ng$ and therefore can prevent this by clarifying the mind and adjusting $s{\check{o}}ng-ch{\check{o}}ng$ through volition, has led Korean oriental medicine to be human based.

• Journal of vocational education research
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• v.36 no.4
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• pp.79-102
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• 2017

The purpose of this study was to develop curriculum framework for entrepreneurship development for adolescents. In order to achieve this goal, we studied and developed entrepreneurship semantics, entrepreneurship education, entrepreneurship education, entrepreneurship education contents. This study was developed through Delphi survey. The results of this study were as follows. First, the meaning of entrepreneurship is Innovative mind-set to create true value by experience into life in order to pursue 'self full-filling life' as the organizer of life. Second, the nature of entrepreneurship education for youth is that entrepreneurship education aims to find and solve new problems through self-management to young people who will lead the future, and to create dynamic challenges and creative changes to create innovative values. Leadership skills, challenging spirit, and ability to solve practical problems'. Third, we developed a general goal for youth and elementary, middle and high school goal for entrepreneurship education. Fourth, as a domain of entrepreneurship education, we have developed 'core discovery', 'entrepreneurial skills', 'becoming an entrepreneur' and developed key themes. Based on the results of this study, we developed a systematic entrepreneurship education linkage and educational condition creation for young people outside schools; entrepreneurship program application and educational condition development according to the operation of the free-learning semester system; the strengthening of business start-up support for youth in late adolescence, the establishment of measures to utilize related institutions in local communities and others.

• KSBB Journal
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• v.20 no.6
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• pp.453-457
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• 2005

We investigated the effect of sulfate re-addition on hydrogen production under sulfur-deprived condition. When the final concentration of sulfate to cell suspensions($0{\sim}120{\mu}M$) was increased, chlorophyll concentration, culture density, and total amount of $H_2$ produced, increased up to an optimal concentration of $30{\mu}M\;MgSO_4$. Maximum hydrogen volume was 236 mL $H_2/L$ culture at $30{\mu}M\;MgSO_4$. However, the addition of excess sulfate(above $MgSO_4\;60{\mu}M$) delayed the start of hydrogen production and the induction of hydrogenase. Accordingly, the final yield of hydrogen production was reduced. Using these results, we attempted the continuous and sustained hydrogen production by sulfate re-addition($30{\mu}M\;MgSO_4$) using a single C. reinhardtii culture for up to 4 cycles. In total, hydrogen production volume was 625 mL $H_2/L$ culture.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.405-412
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• 2012

In the MCFC power generation system, the combustor supplies a high temperature mixture of gases to the cathode and heat to the reformer by using the off-gas from the anode; the off-gas includes high concentrations of $H_2O$ and $CO_2$. Since a combustor needs to be operated in a very lean condition and avoid local heating, a catalytic combustor is usually adopted. Catalytic combustion is also generally accepted as one of the environmentally preferred alternatives for generation of heat and power from fossil fuels because of its complete combustion and low emissions of pollutants such as CO, UHC, and $NO_x$. In this study, experiments were conducted on catalytic combustion behavior in the presence of Pd-based catalysts for the BOP (Balance Of Plant) of 5 kW MCFC (Molten Carbonate Fuel Cell) power generation systems. Extensive investigations were carried out on the catalyst performance with the gaseous $CH_4$ fuel by changing such various parameters as $H_2$ addition, inlet temperature, excess air ratio, space velocity, catalyst type, and start-up schedule of the pilot system adopted in the BOP.

• Clinics in Shoulder and Elbow
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• v.1 no.1
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• pp.109-117
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• 1998

We evaluated the results of the surgery for impingement syndromes and partial thickness tears of the rotator cuff with an average follow-up period of 15 months. One group(group I) of 43 patients, 46 cases underwent arthroscopic subacromial decompression. The other comparable group(group Ⅱ) of 10 patients, II cases underwent open acromioplasty. The average age at operation was 48 years, old. Arthroscopic subacromial decompression achieved slightly better pain relief, the range of the acti ve forward flexion, function, strength and the overall score with improvement from the preoperative condition than open acromioplasty. The patient's satisfaction was better in group I as well. Using the UCLA Shoulder Rating Scale, 89% of group I and 82% of group n had good or excellent results. Preservation of the origin of the deltoid during an arthroscopic acromioplasty reduced the postoperative morbidity and made it possible to start rehabilitation sooner and to achieve the better and more predictable results.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.2
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• pp.125-136
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• 1997

Digestion of a municipal wastewater sludge by the anaerobic sequencing batch reactor(ASBR) was investigated to evaluate the performance of the ASBR process at a critical condition of high-solids-content feed. The reactors were operated at an HRT of 10 days with an equivalent loading rate of 0.8-1.5 gVS/L/d at $35^{\circ}C.$ The main conclusions drawn from this study were as follows: 1. Digestion of a municipal wastewater sludge was possible using the ASBR in spite of high concentration of settleable solids in the sludge. The ASBRS with 3- and 4-day cycle period showed almost identical high digestion performances. 2. No adverse effect on digestion stability was observed in the ASBRS in spite of withdrawal and replenishment of $30\%\;or\;40\%$ of liquid contents. A conventional anaerobic digester could be easily converted to the ASBR without any stability problem. 3. Flotation thickening occurred in thicken step of the ASBRS throughout steady state, and floating bed volume at the end of thicken period occupied about $70\%$ of the working volume of the reactor. Efficiency of flotation thickening in the ASBRS could be comparable to that of additional gravity thickening of a completely mixed digester. 4. Solids were accumulated rapidly in the ASBR during start-up period. Solids concentrations in the ASBRS were 2.6 times higher than that in the completely mixed control reactor at steady state. Dehydrogenase activity had a strong correlation with the solids concentration. Dehydrogenase activity of the digested sludge in the ASBR was 2.9 times higher than that of the sludge in the control reactor, and about 25 times higher than that of the subnatant in the ASBR. 5. Remarkable increase in equivalent gas production of $52\%$ was observed at the ASBRS compared with the control reactor in spite of similar Quality of clarified effluent from the ASBRS and control reactor. The increase in gas production from the ASBRS was believed to be combined results of accumulation of microorganisms, higher driving force applied, and additional long-term degradation of organics continuously accumulated.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1268-1272
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• 2008

Low temperature plasma applied with partial oxidation is a technique to produce synthesis gas from methane. Low temperature plasma reformer has superior miniaturization and start-up characteristics to reformers using steam reforming or CO$_2$ reforming. In this research, a low temperature plasma reformer using GlidArc discharge was proposed. Reforming characteristics for each of the following variables were studied: gas components ratio (O$_2$/CH$_4$), the amount of steam, comparison of reaction on nickle and iron catalysts and the amount of CO$_2$. The optimum conditions for hydrogen production from methane was found. The maximum Hydrogen concentration of 41.1% was obtained under the following in this condition: O$_2$/C ratio of 0.64, total gas flow of 14.2 L/min, catalyst reactor temperature of 672$^{\circ}C$, the amount of steam was 0.8, reformer energy density of 1.1 kJ/L with Ni catalyst in the catalyst reactor. At this point, the methane conversion rate, hydrogen selectivity and reformer thermal efficiency were 66%, 93% and 35.2%, respectively.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.344-352
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• 2015

This study aims to identify the difference in the starting time of the dawn chorus of different species of birds and related environmental conditions. For this study, the bird songs were recorded every 2 hours a day starting from 2 hours before sunrise for a whole spring season (from April to June, 2014) in Korea. The recorded sounds were analyzed to find the starting time of each species' song by sonogram pattern using a sound analyzing program (Adobe Audition CC). To analyze the relationship between the environmental conditions and the time of the birdsong of each species, we collected the data of environmental conditions: daily precipitation, Julian date, time of sunrise and moonrise, temperature data and twilight time from the Korea Meteorological Office. As a result of this study, it was found that there are several statistical correlation between the starting time of the birdsong and environmental conditions (every environmental condition except daily precipitation and time of moonrise). Also, the difference of the starting time among each species were identified. The species were divided into 3 groups (early, mid and late) by their wake-up time. Ring-necked pheasant and yellow-throated bunting were categorized as 'Early' group and all woodpeckers were categorized as'Late' group. This study is significant as it first presented a classification of wild birds in Korea by the starting time of their dawn chorus. However, further studies are required to identify why each species to do their dawn singing at different times.