• 한국연초학회지
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• 제26권1호
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• pp.50-56
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• 2004

The quality of burley leaf tobacco was affected by various toasting conditions. In this study, we determined main factor to influence the quality of burley tobacco on toasting and established proper toasting condition to improve the quality of toasted tobacco. Our results indicated that the main factor to influence the quality of burley tobacco was the amount of treatment and 3rd drying zone temperature. We also found that the proper toasting conditions to improve the quality of toasted tobacco and reduce the smoking irritation were moisture content (34 %), amount of treatment (1,520kg/hr), 1st drying zone temperature (135$^{\circ}C$), 2nd zone drying temperature(145$^{\circ}C$) and 3rd zone drying temperature (147$^{\circ}C$).

• Journal of Biosystems Engineering
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• 제10권1호
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• pp.76-82
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• 1985

To investigate the influence of annealing heat treatment on the mechanical properties at the various weld zone, an experimental study was performed for the structural alloy steel. The results obtained from the experimental works are as follows: 1. Hardness and tensile strength showed the highest value at the heat affected zone, which was 5mm apart from bond zone. With increasing of annealing temperature, hardness and tensile strength were decreased at every weld zone, and bound in heat affected zone was increased. 2. Impact strength was the highest at the filler metal, and increased with increment of annealing temperature at filler metal and base metal. However, both at bond and heat affected zones, impact strength was increased from $700^{\circ}C$ of annealing temperature, and was decreased again over $900^{\circ}C$. 3. Mutual relationship between the mechanical properties at filler and base metals showed a similar linearty to that the common structural steel did. However, it varied unsteadly both at bond and heat affected zones. 4. It may be concluded that proper annealing temperature is $700^{\circ}C$ from the viewpoint of hardness, tensile and impact strength.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.67-67
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• 2001

The structure zone model has been used to provide an overview of the relationship between the microstructure of the films deposited by PVD and the most prominent deposition condition.s. B.AMovchan and AV.Demchishin have proposed it firstls such model. They concluded that the general features of the resulting structures could be correlated into three zones depending on $T/T_m$. Here T m is the melting point of the coating material and T is the substrate temperature in kelvines. Zone 1 ($T/Tm_) is dominated by tapered macrograins with domed tops, zone 2 ($O.3) by columnar grains with denser boundaries and zone 3 ($T/T_m>O.5$) by equiaxed grains formed by recrystallization. J.AThomton has extended this model to include the effect of the sputtering gas pressure and found a fourth zone termed zone T(transition zone) consisting of a dense array of poorly defined fibrous grains. R.Messier found that the zone I-T boundary (fourth zone of Thorton) varies in a fashion similar to the film bias potential as a function of gas pressure. However, there has not nearly enough model for explaining the change in morphology with crystal orientation of the films. The structure zone model only provide an information about the morphology of the deposited film. In general, the nucleation and growth mechanism for granular and fine structure of the deposited films are very complex in an PVD technique because the morphology and orientation depend not only on the substrate temperature but also on the energy of deposition of the atoms or ions, the kinetic mechanism between metal atoms and argon or nitrogen gas, and even on the presence of impurities. In order to clarify these relationship, AI and Mg thin films were prepared on SPCC steel substrates by PVD techniques. The influence of gas pressures and bias voltages on their crystal orientation and morphology of the prepared films were investigated by SEM and XRD, respectively. And the effect of crystal orientation and morphology of the prepared films on corrosion resistance was estimated by measuring polarization curves in 3% NaCI solution.

• 한국터널지하공간학회 논문집
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• 제17권2호
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• pp.91-105
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• 2015

본 연구에서는 3차원 유한요소해석을 실시하여 말뚝의 하부에서 실시된 터널시공으로 인한 말뚝의 거동을 말뚝선단의 상대위치를 고려하여 분석하였다. 수치해석에서는 순수하게 터널굴착으로 인해 유발된 (tunnelling-induced) 말뚝침하, 축력분포, 전단응력 및 겉보기안전율의 변화를 심도 있게 고찰하였다. 말뚝의 선단이 터널굴착에 대한 말뚝선단의 위치를 고려한 영향권 내부에 존재하는 경우 말뚝의 침하는 Greenfield 조건의 최대침하와 인근지반의 침하를 초과하는데 비해, 횡방향 이격거리가 증가하여 영향권 외부에 있는 경우 말뚝의 침하는 그 반대의 경향을 보였다. 말뚝선단이 영향권 내부에 존재하는 경우 tunnelling-induced 인장력이 발생하지만, 말뚝선단이 영향권의 외부에 존재할 경우 말뚝침하를 초과하는 인근지반의 침하로 인해 압축력이 발생하는 것으로 분석되었다. 터널굴착으로 인한 말뚝침하의 증가로 말뚝의 겉보기안전율(apparent factor of safety)은 말뚝선단이 영향권 내부에 존재할 경우 1.0 미만으로 감소하는 것으로 나타나 말뚝의 사용성에 심각한 문제가 발생할 수 있는 것으로 나타났다. 본 연구를 통해 분석한 말뚝선단의 위치에 대한 영향권 내부 및 외부에서의 말뚝의 거동을 말뚝의 침하, 축력 및 겉보기안전율에 대해 심도 있게 고찰하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.33.2-42
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• 2000

This study probes the necessity of establishing a logistic free zone in Port of Busan. It considers the economic effects of establishing the logistic free zone of Busan Port, and suggests policy prescriptions for introducing the free zone system and improving the logistics functions of Busan Port. Using input-output table data, the regression analysis was able to provide a quantitative prediction on effects of making the Busan Port a tariff-free zone. Influence for the regional economy due to the enforcement of the free zone system this research found that a strong positive effects should be expected on the Busan regional economy once the logistic free zone would be set up at the Port of Busan. The positive economic effects on Busan regional industries might be further strengthened if the value-added logistics function of Busan Port could be supplemented by linking to the hinterland of Busan Port.

• Geomechanics and Engineering
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• 제24권5호
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• pp.479-490
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• 2021

Pre-drainage of groundwater in the roof aquifer by boreholes is the main method for prevention of roof water disaster, and the drop in the water level during the drainage leads to the variation of the local stress in the overlying strata. Based on a multitude of boreholes for groundwater drainage from aquifer above the 1303 mining face of Longyun Coal Mine, theoretical analysis and numerical simulation are used to investigate the local stress variation in the process of borehole drainage. The results show that due to the drop in the water level of the roof aquifer during the drainage, the stress around the borehole gradually evolved. From the center of the borehole to the outside, a stress-relaxed zone, a stress-elevated zone, and a stress-recovered zone are sequentially formed. Along with the expansion of drainage influence, the stress peak in the stress-elevated zone also moves to the outside. When the radius of influence develops to the maximum, the stress peak position no longer moves outward. When the coal mining face advances to the drainage influence range, the abutment pressure in front of the mining face is superimposed with the high local stress around the borehole, which increases the risk of stress concentration. The present study provides a reference for the stress concentration caused by borehole drainage, which can be potentially utilized in the optimal arrangement of drainage boreholes in underground mining.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.335-340
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• 2000

The influence of lap splice of longitudinal bars in the plastic hinge zone on the nonlinear behavior characteristics of RC piers has been investigated through the scale model tests. The seismic performance of bridge piers with lap splice is found to be insufficient due to the premature bond failure. On the other hand it is confirmed that the preventing lap splice in the plastic hinge zone enhance the seismic performance considerably even without the seismic details of transverse reinforcements. Bases on these experimental results new seismic detailing concept appropriate to moderate seismicity region has been proposed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.580-585
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• 2000

Recently TEIS model, Two-zone model aid Stanitz equations are often used for off-design performance prediction of centrifugal compressor and pump. The prediction results often agree well with experimental data. However these models and equations have some important variables which have a great influence on overall performance prediction me. But no systematic study about these variables has been performed. So, in this paper, a systematic study about these variables influence on overall performance prediction owe is peformed. Finally the meaning of the variables and the research to be undertaken are discussed.

• 의정연구
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• 제24권1호
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• pp.31-66
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• 2018

본 연구는 한국의 대북정책 결정과정에서 대통령의 영향력이 제한적으로 나타나게 되는 제도적 요인과 정치적 환경을 분석하는 것을 목적으로 한다. 대통령은 국가수반으로서 대북정책에 대한 최고 결정권을 보유하고 있다. 하지만 대북정책에서 대통령의 영향력이 언제나 절대적인 것은 아니다. 권력분립과 민주주의의 제도화에 의한 관료정치, 분점정부 여부나 대통령의 남은 임기 등 정책을 추진하는 시점의 정치적 환경, 정책의 특수성 등 여러 요인들이 대북정책에 대한 대통령의 영향력을 제한하는 요인으로 작동할 수 있다. 본 연구는 2007년 남북한 정상의 합의로 계획되었던 '서해평화협력특별지대' 조성에 관한 정책결정 과정의 동학을 분석하여, 그 과정에서 대통령의 영향력이 제도적 환경과 정치적 여건에 의해 제한적으로 나타나고 있음을 살펴보았다.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.185-194
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• 2014

Seasonal monitoring was implemented to understand the influence of macrophyte bed structure on the composition and trophic interaction of aquatic organisms (algae, zooplankton, macro-invertebrate, and fish) in a shallow wetland (Upo Wetland, South Korea). Distinct division of the plant assemblage (reed zone and mixed plant zone) was observed. The reed zone was composed solely of Phragmites communis, whereas the mixed plant zone comprised a diverse macrophyte assemblage (Salvinia natans, Spirodela polyrhiza, Trapa japonica, Ceratophyllum demersum, and Hydrilla verticillata). Most of the aquatic organisms were more abundant in the mixed plant zone than in the reed zone, and this was positively associated with the seasonal development of macrophyte cover. Stable isotope analysis showed seasonal interactions among aquatic organisms. The majority of aquatic animal (zooplankton, Odonata, and Ephemeroptera) were dependent on epiphytic particulate organic matter (EPOM), and the dependence on EPOM gradually increased toward autumn. Interestingly, Lepomis macrochirus consumed Ephemeroptera and zooplankton in both macrophyte zones, but Micropterus salmoides depended on different food items in the reed zone and the mixed plant zone. Although, M. salmoides in the reed zone showed food utilization similar to L. macrochirus, it consumed Odonata or small L. macrochirus in the mixed plant zone. Based on these results, it appears that differences in the structure of the two macrophyte zones support different assemblages of aquatic organisms, strongly influencing the trophic interactions between the aquatic organisms.