• Journal of Preventive Medicine and Public Health
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• 제45권1호
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• pp.29-36
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• 2012

Objectives: The purpose of this study was to identify any influence of socioeconomic status on smoking and smoking cessation in a situation where genetic factors are controlled. Methods: The sample for this study was 2502 members of the twins and families cohort who participated in the Korean Healthy Twins Study from 2005 to 2009. Groups of brothers or sisters, including twins and fraternal twins, were compared in terms of smoking and smoking cessation behaviors according to differences in socioeconomic status and gender. Results: In a situation with complete control of genetic factors, results showed that the daily smoking amount, cumulative smoking amount, and dependence on nicotine decreased with higher-status occupations, and the rate of smoking and amount of cumulative smoking decreased with higher levels of education. Regarding smoking cessation behavior, a higher level of education was associated with a lower smoking cessation rate, and no significant gender differences were found. Conclusions: Environmental factors had a stronger influence on smoking behavior than did genetic factors. Genetic factors had greater influence on smoking cessation than did environmental factors; however, this requires verification in further studies.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1053-1064
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• 2021

The objective of this research is to empirically study public servant knowledge sharing intention by implementing the Theory of Planned Behavior (TPB) of the Sustainable Development Goals (SDGs). The researcher proposes an extended TPB combined with a perceived environmental concern variable as a determinant of behavioral intention. A total of 150 questionnaires were distributed among civil society and the public sector at the district level in the Central Kalimantan Province of Indonesia. Collectively, 126 inquiries were received. A Partial Least Squares (PLS) analysis was applied to analyze and test the research model and hypothesis. The results show that all of the components of the TPB significantly influenced perceived SDG realization. The findings also partially show that knowledge sharing intention mediated the effect of attitude, perceived behavioral control, and perceived environmental concern on SDG realization. This study confirms that perspectives that affect knowledge sharing intention among public sectors could be approached based on the offered model. Hence, the local government can implement the suggestion offered in this research. The originality of this paper lies in the fact that this study discloses factors affecting knowledge sharing among public servants.

• Geomechanics and Engineering
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• 제30권2호
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• pp.211-218
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• 2022

This study characterizes Proctor and geophysical properties in a broad range of grading and fines contents. The results show that soil index properties such as uniformity and fines plasticity control the optimum water content and peak dry unit trends, as well as elastic wave velocity. The capillary pressure at a degree of saturation less than S = 20% plays a critical role in determining the shear wave velocity for poorly graded sandy soils. The reduction in electrical resistivity with a higher water content becomes pronounced as the water phase is connected A parallel set of compaction and geophysical properties of sand-kaolinite mixtures reveal that the threshold boundaries computed from soil index properties adequately capture the transitions from sand-controlled to kaolinite-controlled behavior. In the transitional fines fraction zone between F_F ≈ 20 and 40%, either sand or kaolinite or both sand and kaolinite could dominate the geophysical properties and all other properties associated with soil compaction behavior. Overall, the compaction and geophysical data gathered in this study can be used to gain a first-order approximation of the degree of compaction in the field and produce degree of compaction maps as a function of water content and fines fraction.

• 한국지반환경공학회 논문집
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• 제23권12호
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• pp.33-39
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• 2022

본 논문은 터널을 구성하고 있는 구성요소(지보재, 주변지반)들의 열화로 인한 터널의 장기거동을 수치해석을 이용하여 예측/분석하였다. 터널의 구성요소들은 시간이 지남에 따라 열화를 겪게 된다. 이러한 열화로 인해 터널의 장기적인 안정성을 예측하는 것은 매우 중요한 이슈이다. 따라서 본 연구에서는 열화를 예측하는 모델을 제시하였으며, 이 모델은 두 개의 파라미터로 구성되어 있다. 그 중 하나는 부재 및 주변지반의 열화로 인해 남아있는 잔류강도를 나타내며, 나머지 하나는 열화되는 모양을 표시한다. 제안한 열화 모델을 이용하여 수치해석을 수행하여 터널의 장기거동을 예측하였다. 그 결과 열화로 인해 터널 주변 지반의 이완응력이 증가하여 터널의 장기적인 안정성에 영향을 미치고 있음을 알 수 있었다.

• 한국환경교육학회지:환경교육
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• 제15권2호
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• pp.1-13
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• 2002

The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

• 한국환경교육학회지:환경교육
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• 제15권1호
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• pp.137-147
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• 2002

The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily Impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene Pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

• 한국기후변화학회지
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• 제5권4호
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• pp.277-284
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• 2014

Biochar application to soil is widely known to have effects of climate change mitigation and soil quality improvement. However, effects of biochar on soil ecosystem are not always positive and some biochars are reported to contain toxic materials which might influence soil ecosystem. In this context, this study aims to investigate behavioral changes of earthworms(Eisenia fetida, Eisenia andrei) in response to different application rates of biochar to artificial soil. Treatment included two types of biochars made from rice husk (RH_Char) and wastewater sludge (SL_Char) with 1% and 10% application rates, respectively. Avoidance test revealed that earthworms did not avoid SL_Char treatments at 1% and 10%, while they rather moved to the RH_Char treatments probably due to higher labile carbon content(Hot water extractable carbon) of the RH_Char. The HWC content of RH_Char was 4 times higher than that of the SL_Char. Results of reproduction test showed that the survival rates, number of juveniles and number of cocoons were not influenced by biochar application except for the treatment of SL_Char at 10% rate. In the SL_Char 10% treatment, fatality was approximately 3.3 times as high as the control and the number of cocoons was 1.3 times higher in the same treatment than the control, indicating that earthworms were under environmental stress. The possible explanation for the stress condition was related to higher Cd, Ni, Cr, and As contents in the SL_Char. Overall results imply that biochar application at low rate might not change earthworms' behavior for the short term, while the reproduction behavior might be negatively influenced under the high application rate.

• 한국초지조사료학회지
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• 제28권2호
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• pp.107-118
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• 2008

본 실험은 NDF 및 ADF 함량이 높은 버섯폐배지(버섯잔사)에 대한 볏짚 대체 가능성을 채식 행동 관점에서 검토할 목적으로 실시하였으며, 시험사료인 농후사료+볏짚(Control: 5.32kg+자유채식), 농후사료+버섯폐배지+볏짚(T1 : 5.32kg+0.82kg+자유채식) 및 농후사료+버섯폐배지+ 볏짚 (T2 : 5.32 kg+1.64 kg+자유채식)를 급여하여 채식 행동 조사를 하였다. 공시가축은 평균체중 357.0+2.9kg인 한우 18두를 이용하였으며, 사료급여에 있어서는 농후사료와 버섯페배지는 1일 2회로 반량씩 급여하였으며 볏짚은 자유채식토록 하였다. 볏짚 채식량은 Control구가 2.66kg으로서 가장 높게, T2구가 2.03 kg으로 가장 낮게 나타난 반면, 총채식량 및 NDF 채식량은 T2 > T1 > Control구 순으로 높게 나타났다. 채식시간은 Control구가 289.3분, T2구가 290.5로 비슷했고 T1구가 236.0분으로 가장 적었다(p<0.05). 반추시간에 있어서는 버섯폐배지 첨가량을 0%(0.0kg), 15%(0.82kg) 및 30%(1.64kg)로 증가 시켜줌에 따라 반추시간은 451.0분에서 359.5분으로 직선적으로 감소하였다(p<0.05). 이는 버섯폐배지의 사료입자 크기가 매우 작았던 것에 기인된 것으로 생각된다. 1일 저작시간, 식괴수, 저작회수와 식괴당 저작수 및 사료가치지수는 볏짚을 급여한 대조구에서 모두 높게 나타났다(p<0.05). 그러나 식괴당 반추시간은 T2(69.4분)에서, 분 당 식괴수는 T1구(1.07번)에서 높게 나타났다(p<0.05). 채식율, 반추효율 및 저작효율성에 있어서는 버섯폐배지 첨가 급여구(T1, T2)가 무첨가 급여구(Control)에 비하여 높게 나타났으며, 이는 높은 채식량과 버섯폐배지의 작은 입자도가 관여한 것으로 생각된다. 군 행동은 모든 구(Control, T1 및 T2)에서 농후사료 급여시에 통일된 행동을 보였고, 반추 및 휴식에 있어서 군 행동은 처리 간 큰 차이가 없는 것으로 나타났다. 이상의 결과 육성우 배합사료에 버섯폐배지 15% 및 30%를 첨가 급여함으로서 반추시간, 식괴수, 저작수 및 FVI치는 다소 낮은 결과치를 보였으나, 채식행동에 큰 문제가 될 정도는 아니며, 오히려 채식율, 반추효율 및 저작효율에 있어서 무첨가구에 비하여 첨가구가 높았던 점을 감안 할 때 한우 육성우 조사료원으로서 대체 가능성을 기대할 수 있다.

• Geomechanics and Engineering
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• 제5권3호
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• pp.195-221
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• 2013

A centrifuge model study is carried out to investigate the behavior of pile subject to negative skin friction induced by pile installation, ground water drawdown and surcharge loading. A single end-bearing pile is examined as the induced negative skin friction would induce the most severe stress on the pile structural material as compared to friction piles. In addition, the behavior of the pile under simultaneous negative skin friction and dead/live loads is examined. To facilitate detailed interpretations of the test results, the model setup is extensively instrumented and involves elaborate test control schemes. To further examine the phenomenon of negative skin friction on an end-bearing pile, finite element analyses were conducted. The numerical analysis is first validated against the centrifuge test data and subsequently extended to examine the effects of pile slenderness ratio, surcharge intensity and pile-soil stiffness ratio on the degree of mobilization of negative skin friction induced on the pile. Finally experimental and numerical studies are conducted to examine the effect of applied transient live load on pile subject to negative skin friction.

• 한국환경과학회지
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• 제19권9호
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• pp.1119-1127
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• 2010

The behavior of copper throughout the whole process of wastewater treatment plant that uses the activated sludge process to treat the wastewater of petrochemical industry that contains low concentration of copper was investigated. Total inflow rate of wastewater that flows into the aeration tank was $697\;m^3$/day with 0.369 mg/L of copper concentration, that is, total copper influx was 257.2 g/day. The ranges of copper concentrations of the influent to the aeration tank and effluent from the one were 0.315 ~ 0.398 mg/L and 0.159 ~ 0.192 mg/L, respectively. The average removal rate of copper in the aeration tank was 50.8 %. The bioconcentration factor (BCF) of copper by microbes in the aeration tank was 3,320. The accumulated removal rate of copper throughout the activated sludge process was 71.3%, showing a high removal ratio by physical and chemical reactions in addition to biosorption by microbes. The concentration of copper in the solid dehydrated by filter press ranged from 74.8 mg/kg to 77.2 mg/kg and the concentration of copper by elution test of waste was 2.690 ~ 2.920 mg/L. It was judged that the copper concentration in dehydrated solid by bioconcentration could be managed with the control of that in the influent.