• Bulletin of the Korean Chemical Society
• /
• 제29권12호
• /
• pp.2434-2440
• /
• 2008

The effect of sodium (Na) promotion was studied in the biphenol (BP) hydrogenation using various Pd/C catalysts. Different amounts of sodium metal were used for promotion with Pd/C and their effects on BP hydrogenation were observed. The promotion order was changed to compare the effect of the position of the promoter in relation to the palladium (Pd) metal on the catalytic activity and yield of the final product, bicyclohexyl-4,4'-diol (BHD). Pd/C catalysts prepared from different methods were also sodium-promoted and the changes of the reaction pathway according to the type of promoted Pd/C catalyst were compared.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
• /
• pp.279-283
• /
• 2004

Thermal postbuckling and vibration analyses of functionally graded plates (FG plates) are performed. The nonlinear finite element equation based on the first-order shear deformation plate theory is formulated for the FG plate. The von Karman strain-displacement relation is used to account for the thermal large deflection. The incremental method considering the effect of the initial deflection and the initial stress is adopted for temperature-dependent material properties of functionally graded materials. The numerical result shows characteristics of the thermal postbuckling and vibration of FG plates in the pre- and post- buckled regions.

• 대한지구과학교육학회지
• /
• 제10권1호
• /
• pp.38-49
• /
• 2017

이 연구는 예비교사들이 교육실습을 통해 무엇을 느꼈으며 교육실습에 대해 어떻게 생각하고 있는지 알아보는 데 목적이 있었다. 특히 이번 연구에서는 예비교사들이 실습기간 동안 느낀 교육실습과 대학 교육과정의 관계를 분석하였다. 연구를 위해 교사 양성 기관에 재학 중인 3학년 학생 20명이 참여하였다. 연구 결과, 첫째, 교육실습을 위해 대학에서 배운 내용학 지식과 교육학 지식과 관련된 교과들이 도움이 되었다고 예비교사들은 응답하였다. 둘째, 예비교사들은 교육실습은 수업을 보는 것만으로도 도움을 줄 수 있다고 응답하였다. 셋째, 예비교사들은 교육실습을 위해 수업시연의 기회가 대학 교육과정 내에서 이루어져야 한다고 생각하였다. 그리고 다양한 교수 기술과 새로운 교수방법을 배울 수 있는 강의가 개설되기를 원하고 있었다. 넷째, 예비교사들은 수업의 완성도를 높이기 위해서는 교사와 학생간의 관계가 중요하다는 것을 이야기하였다. 그리고 이것은 교육현장에서는 그들이 생각한 것보다 더 중요하다는 것을 느꼈다고 응답하였다. 더불어 그들은 이런 교육실습을 통해 많은 것을 경험하는 것은 매우 도움이 된다고 생각하고 있었다. 이러한 결과를 통해 교육실습은 미래 교사가 될 예비교사들을 위해 매우 필수적인 과정이며 많은 영향을 준다는 것을 알 수 있었다. 아울러 교육실습과 관련된 교사 양성 기관의 교육과정에 대한 검토 및 수정이 요구된다고 하겠다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권17호
• /
• pp.7701-7705
• /
• 2015

Background: Thyroid hormones (TH) are regulated by the hypothalamic-pituitary axis, which plays an important role in cell growth, differentiation, development and other aspects of metabolism. It is believed that an active hypothalamic-pituitary axis increases the susceptibility of thyroid dysfunction during systemic chemotherapy. In order to investigate the relation between thyroid function and chemotherapy the present study was designed to investigate TH in breast cancer patients receiving at least three cycles of chemotherapy. The levels of TH were measured at the baseline and before each cycle of chemotherapy. Materials and Methods: Blood samples for estimation of TH levels were collected from 80 (pre-menopausal-40; post-menopausal-40) breast cancer patients just before they were undergoing - $1^{st}$, $2^{nd}$, $3^{rd}$ and $4^{th}$ cycle of chemotherapy. The serum was separated and $T_3$, $T_4$ and TSH levels were determined by chemiluminescence method. Results: $T_3$ and $T_4$ were found significantly decreased and TSH was found significantly increased after $1^{st}$ (p<0.001), $2^{nd}$ (p<0.0001) and $3^{rd}$ cycle of chemotherapy (p<0.0001). The variation of $T_3$ levels (decreased) and TSH levels (increased) was found more in post-menopausal (p<0.0001) women then in pre-menopausal women after $3^{rd}$ cycle of chemotherapy as compared to baseline (p<0.001). Conclusions: TH were remarkably altered after each cycle of chemotherapy leading to decline in thyroid function of breast cancer patients. Further, the results also indicated that post-menopausal women were more prone towards decline in thyroid function then pre-menopausal women. The present study proposes the monitoring of TH after each cycle of chemotherapy in breast cancer patients.

• Journal of Plant Biology
• /
• 제17권1호
• /
• pp.15-21
• /
• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.

• 과학교육연구지
• /
• 제44권1호
• /
• pp.1-14
• /
• 2020

이 연구에서는 '계절별 낮과 밤의 길이'에 대한 초등 예비교사들의 인식을 규명하기 위하여 수도권 소재 교육대학교 4학년 재학생 30명이 글과 그림으로 설명한 내용을 분석하였다. 주요 연구 결과는 다음과 같다. 첫째, 예비교사들이 글 설명에서 가장 많이 사용한 용어는 남중고도, 자전축, 공전 순으로 나타났으며, 글 설명보다 그림 설명에서 오개념이 많이 드러났다. 둘째, 글과 그림 설명을 종합하여 예비교사들의 인식을 분석함으로써 공전과 관련하여 자전축이 기울어져서 지구와 태양 사이의 거리가 가까워진다거나, 지구의 공전 궤도 반지름 변화에 의해 계절 변화가 생긴다는 등 과학적 오류를 포함하는 설명 유형을 확인하였다. 또한 지구의 자전과 관련하여 계절별 남중고도는 변화하나 태양이 뜨고 지는 위치는 변화하지 않는다는 등의 설명 유형도 나타났으며, 지구의 공전과 자전 모두와 관련하여 과학적 오류를 포함하는 사례도 일부 나타났다. 분석 결과를 바탕으로 과학 지식을 활용하여 특정 현상의 설명 체계를 구성해 보는 경험의 부족, 자연 현상에 대한 관찰 및 관측 경험의 부족, 인지적 갈등을 유발하는 다른 설명 체계에의 노출 부족 등의 문제를 논의하였다. 이상의 논의를 토대로 초등 교사 양성 프로그램의 과학 영역에서 예비교사들의 이해를 제고할 수 있는데 구체적이고 실질적인 도움이 될 수 있기를 기대한다.

• 한국수산과학회지
• /
• 제2권2호
• /
• pp.161-172
• /
• 1969

Ten experimental tuna long line fishing operations were performed with the long lines A and B, in combination casting orders of BA and AB. The long line B differs from A in its additional main line length per basket and its greater depth of submersion (Table 1). The BA casting order results in an AB hauling order, so that the long line B is casted at an earlier time of a day and fishes for a longer period than A line (fig. 2). The number of fish caught was divided into subclasses in order to be subjected to $x^2-tests$ (Table 2). The first series of $x^2-tests$ were calculated using the hooking rates of two subclasses with other factors pooled (Table 3). The second series of $x^2-tests$ were calculated to obtain the interactions between two subclasses when other factors differed (Table 4). Attention was paid to the extremely small interactions as well as to the large interactions in order to find out whether a factor functions in the same way or in a contradictory way when the other factors involved differ. The test result is summarized in Table 5. The relationship between the hook casting time (relative to the sunrise time) and the hooking rates reveals the feeding behavior of particular species (fig. 3) A high hooking rate for yellowfin tuna shown in the period from one hour before sunrise to the moment of sunrise suggests that they feed actively in that period. Their poor hooking rate on earlier casted hooks suggests that they do not feed well under conditions of darkness and that they feed best while the hooks are sinking. Furthermore it is likely that yellowfin tuna maintain a shallow depth in the daytime, for the $x^2$ interaction between the line casting order BA and AB shows their persistant preferance of the long line A regardless of line casting order. Bigeye tuna show their feeding behavior under conditions of darkness, and show a preference for the sea's deeper layer. Alepisaurus borealis (Gill) show their feeding behavior under conditions of darkness more significantly than the bigeye tuna and their preferance for deep layers is also more significant. Marlins (mainly Makaria mazara) show a feeding behavior which is similar to the yellowfin tuna. The author emphasizes that certain variations of the hooking rates in relation to the line easting time were caused by an inadequate fishing depth as well as by the fish preference for a particular feeding time. When the part of the line casted in pre-dawn hours and hauled in the pre-sunset hours show a significantly lower hooking rate than other parts of the line, then it is concluded that tile hooks settled in a sea layer too deep for feeding.

• 유통과학연구
• /
• 제12권8호
• /
• pp.123-132
• /
• 2014

Purpose - Recently, Korean companies have been struggling to perform well in the larger smartphone market in China, which is regarded as a blue ocean area. First, it is very important to accurately understand the Chinese consumers, who have a different consumption culture and value system from the Korean culture and system. This would help to identify priorities for the Chinese market. Further, considering the smartphone industry, where technological change is rapid, Korean companies will need to take prompt measures about market trends in order to establish strong competitiveness. Consequently, this study focused on analyzing the relationship between the variables of consumption value, satisfaction, and loyalty in the Chinese smartphone market. The principal dimensions of consumption value, which smartphones have, was analyzed, and the influence on satisfaction was identified. Moreover, the relationship among the variables of satisfaction, attitudinal loyalty, and behavioral loyalty was empirically analyzed. Research design, data, and methodology - This study examined the relationships between various consumption values (functional value, emotional value, social value, epistemic value, and economic value), along with satisfaction and loyalty. The data were collected through a questionnaire survey that was circulated to 310 customers who were users of smartphones in Chingdao and Yeontae regions in China. The survey was conducted from June 23 to August 4, 2013. A total of 301 responses to the questionnaires were collected and used for the data analysis. Moreover, a path analysis based on Lisrel 8.54 was used for the hypothesis test. Results - The variables of functional value, emotional value, social value, and epistemic value were revealed to have positive effects on satisfaction related to smartphone usage. However, the variables of monetary cost and psychological cost were not found to have negative effects on satisfaction related to smartphone usage. Moreover, satisfaction positively influenced attitudinal loyalty related to smartphone usage, but did not have a significant influence on behavioral loyalty related to smartphone usage. Specifically, satisfaction is essential, but not a sufficient condition for building behavioral loyalty in relation to smartphone usage. In addition, attitudinal loyalty positively influenced behavioral loyalty in relation to smartphone usage. Conclusions - First, this study shows that functional value, emotional value, social value, and epistemic value in relation to smartphone usage are important for marketing in the Chinese smartphone market. Particularly, functional value and emotional value play pre-eminent roles as regards customer loyalty in the use of smartphones. Second, the results of this study reveal that the variables of monetary cost and psychological cost are not important to the Chinese consumers. Specifically, the smartphone price and cognitive effort are not perceived as value barriers. Third, satisfaction did not guarantee behavioral loyalty in relation to smartphone usage, and the strategic approach for improving the repurchase and referral action in relation to smartphones based on solid attitudinal loyalty would be desirable and should be the focus of the marketing activities of Korean smartphone companies.

• 한국방재학회 논문집
• /
• 제10권3호
• /
• pp.1-11
• /
• 2010

본 연구에서는 경기도 용인시 기흥구 구갈동(구갈역세권)과 보라구역, 중동구역 일대를 중심으로 개발계획, 개발잠재력, 입지여건과 아울러 녹색 및 재해예방 인프라에 대한 4가지 측면을 고려하여 대상지의 투자가치 평가를 통한 전략적 도시관리 방안을 연구하였다. 방법론 측면에서는 평가항목간의 상관관계를 고려할수 있는 네트워크 분석적 의사결정법을 통하여 판단해보고자 하였다. 분석 결과 개발계획에서는 개발용도, 키테넌트, 자금조달, 마케팅순으로, 개발잠재력에서는 시장성, 정체성, 역사성 순으로, 입지여건에서는 토지이용, 주변환경, 교통환경순으로, 마지막으로 녹색 및 재해예방인프라에서는 자연재해예방, 인적재해예방, 사회적 재해예방순으로 나타났다. 본 연구의 결과는 향후 도시개발사업 추진하는데 있어 합리적인 사전 평가방안으로 활용할 수 있을 것이라 본다.

• 대한토목학회논문집
• /
• 제30권4C호
• /
• pp.193-200
• /
• 2010

본 연구에서는 사질토의 응력이력 효과를 평가하기 위해 정지토압계수($K_0$)를 추정하는 방법을 제안하였다. 제안된 방법은 사질토의 상태정수(${\psi}$)를 매개로 하여 $K_D/K_{0-\psi}$ 관계와 $E_D/{\sigma_m}^'-{\psi}$ 관계를 조합한 $K_D/K_0=\chi(E_D/{\sigma_m}^')^{\delta}$ 의 형태로 표현된다. 챔버에서 수행된 딜라토미터시험 결과에 의하면 본 연구에서 제안된 관계식은 응력이력에 영향을 받지 않는 것을 알 수 있었다. 제안된 방법은 사질토의 정지토압계수 추정 시 딜라토미터 시험결과 만을 이용하는 간편한 방법이며, 콘관입시험과 딜라토미터 시험 결과를 동시에 이용하는 기존의 방법에 비해 간단하고 신뢰성이 높은 장점이 있다.