• 한국지하수토양환경학회지:지하수토양환경
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• 제28권5호
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• pp.12-24
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• 2023

The Songji lagoon is brackish environment with a mixture of saline and fresh water, and the interaction of groundwater-lagoon water creates a physicochemical gradient. Although some studies have been conducted on the hydrological and geochemical characteristics of the Songji lagoon, microbial ecological studies have not yet been conducted. In this study, we investigated the effect of groundwater and surface water interaction on water quality as well as microbial community changes in the Songji Lagoon using 16S rRNA gene sequencing. Hydrochemical analyses show that samples were classified as 5 hydrochemical facies (HF) and hydrochemical facies evolution (HFE) revealed the intrusion phase was more dominant (57.9%) than the freshening phase (42.1%). Higher microbial diversity was found in freshwater in comparison to saline water samples. The microbial community at the phylum level shows the most dominance of Proteobacteria with an average of 37.3%, followed by Bacteroidota, Actinobacteria, and Patescibacteria. Heat map analyses of the top 18 genera showed that samples were clustered into 5 groups based on type, and Pseudoalteromonas could be used potential indicator for seawater intrusion.

• Structural Engineering and Mechanics
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• 제50권6호
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• pp.797-816
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• 2014

Cooling tower is analyzed as an assembly of layered nonlinear shell elements. Geometric representation of the shell is enabled through layered nonlinear shell elements to define the different layers of reinforcements and concrete by considering the material nonlinearity of each layer for the cooling tower shell. Modal analysis using Ritz vector analysis and nonlinear time history analysis by direct integration method have been carried out to study the effects of the inclination of the supporting columns of the cooling tower shell on its dynamic characteristics. The cooling tower is supported by I-type columns and ${\Lambda}$-type columns supports having the different inclination angles. Relevant comparisons of the dynamic response of the structural system at the base level (at the junction of the column and shell), throat level and at the top of the tower have been made. Dynamic response of the cooling tower is found to be significantly sensitive to the change of the inclination of the supporting columns. It is also found that the stiffness of the structure system increases with increase in inclination angle of the supporting columns, resulting in decrease of the period of the structural system. The participation of the stiffness of the tower in structural response of the cooling tower is fund to be dependent of the change in the inclination angle and even in the types of the supporting columns.

• 한국음향학회지
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• 제20권5호
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• pp.14-20
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• 2001

힘평형 서보 가속도계의 성능특성을 결정하는 4개의 팔로 구성된 질량지지 장치를 설계·제작하였다. 팔의 두께와 인가질량의 변화에 따른 질량지지 장치의 응답특성을 유한 요소법을 이용하여 계산하고, 레이저 간섭계를 이용하여 간섭무의 수의 변화와 응답 전압값을 이용하여 가속도계의 응답특성을 측정하였다 팔의 길이와 두께가 변화함에 따라 응답특성은 크게 변화하였으며, 인가질량의 변화는 질량지지 장치의 응답특성변화에 큰 영향을 미치지 못함을 알 수 있었다. 수치해석과 레이저 간섭계로 측정한 공진주파수가 5%차이의 근사한 값을 얻을 수 있었다.

• 약학회지
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• 제41권1호
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• pp.139-146
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• 1997

In the present study, capsaicin-induced desensitization of peripheral sensory nerves were investigated by using guinea pig bronchi, in which these nerves are stimulated with cap saicin to produce a contractile response via the release of sensory neuropeptides such as substance P and neurokinin A. The contractile response to capsaicin was inhibited by the combination of CP96345 and SR 48968 suggesting that the excitatory effect of capsaicin is mediated via both the tachykinin NK-1 and NK-2 receptor. Capsaicin produced in vitro-desensitization in dose-dependent manner, but after this in vitro-desensitization the response to NK-1 and NK-2 receptor agonist did not change. Systemic administration (s.c.) of capsaicin also desensitized significantly bronchial tissues but could not produce any change in the contractile response to the selective agonists of NK-1 and NK-2 receptor. Therefore, the present results suggest that functional desensitization to capsaicin-induced contractile response in guinea pig bronchi does not involve NK-1 and NK-2 receptor, while excitatory effect of capsaicin is mediated via both NK-1 and NK-2 receptor. In conclusion, it is suggested that capsaicin- induced excitation and desensitization involves somewhat different pathways.

• Journal of Plant Biology
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• 제26권3호
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• pp.131-139
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• 1983

Temperature response of amoebae of thermotactic mutants have been investigated. Amoebae of the mutant strain HO 428 showed positive thermotaxs which is strong at lower temperaturs and drops sharply above the growth temperature of amoebae. The temperature response of HO 428 amoebae was not affected by the length of amoebae on the grdients. HO 596 amoebae seemed to have both positive and negative thermotactic responses shortly after food depletion. Longer exposure of these amoebae on the thermal gradients induced a stronger negative response at lower temperatures and an apparent positive response at higher temperatures. A similar changes could be observed in HO 1445 amoebae. Based on the steady positive thermotactic response by HO 428 amoebae and the mode of change in termperature response at higher temperatures, 24$^{\circ}C$ and $25^{\circ}C$, by HO 596 amoebae, a model for the temperature response of vegetative Dictyostelium discoideum amoebae, strain HL 50, has been proposed. The main features of the model are: a positive response at the thermal gradients with midpoint temperatures lower than the growth temperatures of amoebae and a negative response above it.

• 산업융합연구
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• 제20권8호
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• pp.127-136
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• 2022

본 연구는 코로나19 상황에서 우리나라 국민이 경험한 팬데믹의 개인정서와 사회변화 인식이 엔데믹 이후 재난대처 인식에 미치는 영향을 실증적으로 분석하기 위해 다중회귀모형을 활용하여 수행하였다. 이 연구를 위해 한국언론 진흥재단에서 실시한 「코로나19 이후 국민의 일상 변화 조사」를 사용하였고, 996명(남 508명, 여 488명)을 연구대상으로 설계하였다. 연구 결과, 코로나19 긍정정서와 사회변화 인식 요인들은 재난대처 인식에 정(+)의 영향을 미쳤으며, 공동체의식은 재난대처 인식에 부(-)의 영향을 미치는 코로나19 부정정서를 완화시켜 주는 조절효과가 있었다. 엔데믹 이후 재난대처 인식에 상대적으로 가장 많은 영향을 미치는 요인은 재난 상황시 우리나라 사회에 대한 자긍심과 안정감을 갖는 코로나19 긍정정서와 공동체의식이었다. 따라서 본 연구는 엔데믹 이후 재난 발생 상황에서 수행되는 정부의 선행 및 후속 조치 방안들이 국민에게 자긍심과 안정감을 주는 체계적인 재난대처 메뉴얼과 컨트롤 타워가 더 강력하게 요청되며, 국민에게는 재난 상황에서 개인적인 행동과 판단으로 대처하기보다는 재난을 함께 극복하려는 공동체의식이 요청됨을 시사한다.

• 대한감각통합치료학회지
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• 제6권1호
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• pp.63-69
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• 2008

서론: 본 연구는 감각통합장애(감각조절장애와 실행장애의 혼합) 아동의 사례보고를 통해 아동의 내적동기를 유발하기 위한 감각통합 치료의 방향설정 과정을 살펴보고 적응반응의 변화에 대해 제시하고자 하였다. 본론: 연구대상은 2008년 감각통합치료과정의 단기집중 프로그램에 참여한 만 5세 10개월 된 남아이다. 아동의 평가결과에 기초하여 연구목표, 치료계획 및 내용을 제시하였고 4 세션 치료기간 동안의 적응반응 변화를 분석하였다. 결론: 본 연구결과, 감각통합치료를 통한 적응반응의 향상을 볼 수 있었고 아동의 내적동기 유발이 중요하다는 것을 알 수 있었다. 그러나 향후에는 감각통합치료를 통한 치료효과를 보다 객관적으로 제시하고 일상에서의 변화를 함께 고려해야 할 것이다.

• 전력전자학회논문지
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• 제17권3호
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• pp.205-212
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• 2012

This paper proposes the fuzzy logic based variable step-size MPPT (Maximum Power Point Tracking) method for the stability at the steady state and the improvement of the transient response in the wind power system. If the change value of duty ratio is set on stability of the steady state, MPPT control traces to maximum power point slowly. And if the change value is set on improvement of the transient response, the system output oscillates at the maximum power point. By adjusting the step size with fuzzy logic, it can be improved the MPPT response speed and stability at steady state when MPPT control is performed to track the maximum power point. The effectiveness of the proposed method has been verified by simulations and experimental results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 춘계학술대회 논문요약집
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• pp.188-188
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• 2004

Modal testing and analysis is a primary tool for obtaining reliable models to represent the dynamics of structures. When a structure is tested in order to collect measured data in modal testing, we usually use attached accelerometers to pick up the response data. Change in modal parameters due to the mass of transducers in modal testing is a well-known problem. The disadvantages are the shift of measured modal frequencies and the change of modal shapes, which can cause inaccurate results in further analysis. Modal analysis methods in frequency domain are based on a set of measured frequency response functions(FRF).(omitted)

• Nuclear Engineering and Technology
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• 제30권5호
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• pp.387-395
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• 1998

In general, the laminated rubber bearing (LRB), a composite structure laminated with the elastic rubber and steel plates, has a complex hysteretic nonlinear characteristics in relationships between the restoring force and shear deflection. The representative nonlinear characteristics of LRB include the change of hysteresis loop with cyclic shear deflections and the hardening effects at large shear deflection regions. Changes of the hysteresis loop of LRB with cyclic shear deflections affect the horizontal stiffness and the damping characteristics. The hardening behavior of LRB in large shear deflection region results in an increased horizontal stiffness and therefore, has a great impacton the seismic responses. In this paper, the seismic response analysis is carried out using the modified hysteretic bi-linear model of LRB, which takes into account the hysteresis loop change and the hardening behavior with cyclic shear deflection. The results on seismic responses are compared with those obtained using the widely used hysteretic hi-linear model. The new model is found to reveal the greater amount of peak acceleration response.