• 한국구조물진단유지관리공학회 논문집
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• 제24권1호
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• pp.24-34
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• 2020

본 연구는 nano-silica solution(NSS)을 배합수 중량치환방법을 사용한 OPC-slag cement의 특성에 관한 연구이다. 새로운 치환방법은 선행연구들보다 높은 NSS 치환율의 시멘트에 대한 거동을 연구하기 위한 기초 단계이다. NSS는 배합수 중량의 10%, 20%, 30%, 40%, 그리고 50% 치환하였다. 그 결과 역학적 및 미세구조적 특성이 향상되는 결과를 보였다. 이는 두 가지 원인으로 요약된다. 첫 번째는 NSS를 배합수중량 치환하면 나노 실리카 입자의 균질한 분산작용이 향상된다. 이는 초기 수화작용을 촉진한다. 두 번째는 배합수 보다 밀도가 큰 NSS의 치환은 w/b를 감소시킨다. 이는 치밀한 수화반응물질을 형성시킨다. 새로운 치환방법은 선행연구에서 밝혀진 분말형 나노 실리카 입자를 사용한 결과와 비교하여 역학적과 미세구조 특성의 저하가 나타나지 않았다. 따라서 본 연구에서 사용한 NSS를 배합수 중량 치환한 방법은 OPC-GGBFS cement의 배합에 적용 가능할 것으로 판단된다.

• 문화기술의 융합
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• 제5권4호
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• pp.147-155
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• 2019

광해군 즉위 후의 경기대동법(선혜법), 인조 즉위 후의 강원도대동법, 효종 즉위 후의 충청도 및 전라도 대동법의 시행은 새로이 즉위한 왕에게 기대를 걸어 백성들의 고단한 삶을 개선시키려 했던 위대한 경세가(輕世家)의 대단한 노력이 있었기에 가능했던 것이다. 그러나 이 세 왕의 즉위 후 시행된 대동법은 그 시행과 관련하여 큰 위기에 당면하게 된다. 시행과 관련된 위기의 차이점은 광해군 때와 인조 때의 대동법은 시행결정 후 시행은 즉시 이루어졌으나 얼마 안가서 폐지위기에 놓였다는 것이고, 효종 때의 충청도 및 전라도 대동법은 시행 전에 극심한 반대에 부딪쳤으나 그 반대를 극복하고 시행된 이후에는 폐지위기를 맞지 않고 계속 시행되었다는 것이다. 본 연구에서는 이러한 세 왕의 즉위와 그 새로운 왕에게 기대를 걸어 백성의 편안한 삶을 위한 대동법의 시행을 성공시킨 경세가(輕世家)들의 노력에 대하여 검토해 보았다. 광해군 때의 한백겸과 이원익 및 황신, 인조 때의 조익과 이원익, 효종 때의 김육 등은 공물방납의 폐단을 개선하여 백성들의 고달픈 삶을 개선시켜 주고자 하는 공통적인 생각을 가진 인물들이었다. 이들은 성리학의 이론적인 해석에만 치중하는 것이 아닌 그 해석을 바탕으로 백성을 위한 올바른 정치를 현실에서 실천하는 경세가(輕世家)적인 능력을 발휘하였다. 그 결과물이 바로 대동법 시행을 위한 정책입안과 시행인 것이다.

• 대한화장품학회지
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• 제47권4호
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• pp.305-316
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• 2021

본 연구는 타마린드씨검(Tamarindus indica seed gum, TG)과 에탄올, 폴리올의 반응성 및 산·염기 반응 실험을 기반으로 하여 최종적으로 지지체가 없는 것을 특징으로 하는 새로운 겔 시트 마스크 개발에 관한 것이다. TG와 특정 알코올류를 각각 일정 혼합 비율로 혼합하는 경우, 각 성분과의 반응에 의해 투명한 겔을 형성하므로 이를 이용하여 지지체가 없는 겔 시트 마스크를 얻을 수 있었다. 피부 밝기 개선을 극대화하기 위해 산·염기 반응의 탄산 시스템을 도입하기 위해 산 원료별 함량 실험을 진행하였고, 분광측색계와 수분 측정기기를 이용하여 피부 밝기 및 보습력 평가를 진행하였다. 본 연구를 통해 TG와 에탄올, 폴리올의 수소 결합에 의한 겔화 반응을 기반으로 하여 여러 제형으로의 개발이 가능할 것으로 생각되어, 본 연구에서 소개된 겔 시트 마스크 제형은 우수한 보습력을 부여하므로 향후 새로운 제품 개발에 도움이 될 것으로 기대된다.

• Parasites, Hosts and Diseases
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• 제61권3호
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• pp.282-291
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• 2023

Despite the recent progress in public health measures, malaria remains a troublesome disease that needs to be eradicated. It is essential to develop new antimalarial medications that are reliable and secure. This report evaluated the pharmacokinetics and antimalarial activity of 1,2,6,7-tetraoxaspiro[7.11]nonadecane (N-89) using the rodent malaria parasite Plasmodium berghei in vivo. After a single oral dose (75 mg /kg) of N-89, its pharmacokinetic parameters were measured, and t_1/2 was 0.97 h, T_max was 0.75 h, and bioavailability was 7.01%. A plasma concentration of 8.1 ng/ml of N-89 was maintained for 8 h but could not be detected at 10 h. The dose inhibiting 50% of parasite growth (ED₅₀) and ED₉₀ values of oral N-89 obtained following a 4-day suppressive test were 20 and 40 mg/kg, respectively. Based on the plasma concentration of N-89, we evaluated the antimalarial activity and cure effects of oral N-89 at a dose of 75 mg/kg 3 times daily for 3 consecutive days in mice harboring more than 0.5% parasitemia. In all the N-89-treated groups, the parasites were eliminated on day 5 post-treatment, and all mice recovered without a parasite recurrence for 30 days. Additionally, administering oral N-89 at a low dose of 50 mg/kg was sufficient to cure mice from day 6 without parasite recurrence. This work was the first to investigate the pharmacokinetic characteristics and antimalarial activity of N-89 as an oral drug. In the future, the following steps should be focused on developing N-89 for malaria treatments; its administration schedule and metabolic pathways should be investigated.

• 통합자연과학논문집
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• 제16권4호
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• pp.103-110
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• 2023

Invasive species are organisms that are introduced into places outside of their natural distribution range. The global pet trade is facilitating the introduction of invasive species into new countries and areas. Among the introduced alien species, turtles are one of the most common animal groups whether lives in wetland ecosystems, such as wetlands or reservoirs. Like other countries around the world, exotic turtles is becoming a growing concern for the wetland ecosystem in South Korea. In this study, we report new reports of subspecies of Painted turtle (Chrysemysspp.): Chrysemys picta marginata, C. p. bellii and C. dorsalis, from the reservoirs in downtown Cheongju and Gwangju, South Korea. We used morphological features, such as the characteristics of the legs, plastron, and carapace, to identify the turtles. It is assumed that all turtles were artificially released into nature. Considering the increasing number of reports on the introduction of alien invasive turtles in Korean wetlands, we recommend the formulation of an immediate and systematic management plan for pet trades and organized continuous monitoring programs.

• 대한지리학회지
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• 제38권
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• pp.15-36
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• 1988

In this paper, I consider the development of methods in contemporary human geography in terms of a dialectical relation of action and structure, and try to draw a new horizon of method toward which geographical research and spatial theory would develop. The positivist geography which was dominent during 1960s has been faced both with serious internal reflections and strong external criticisms in the 1970s. The internal reflections that pointed out its ignorance of spatial behavior of decision-makers and its simplication of complex spatial relations have developed behavioural geography and systems-theoretical approach. Yet this kinds of alternatives have still standed on the positivist, geography, even though they have seemed to be more real and complicate than the previous one, The external criticisms that have argued against the positivist method as phenomenalism and instrumentalism suggest some alternatives: humanistic geography which emphasizes intention and action of human subject and meaning-understanding, and structuralist geography which stresses on social structure as a totality which would produce spatial phenomena, and a theoretical formulation. Human geography today can be characterized by a strain and conflict between these methods, and hence rezuires a synthetic integration between them. Philosophy and social theory in general are in the same in which theories of action and structural analysis have been complementary or conflict with each other. Human geography has fallen into a further problematic with the introduction of a method based on so-called political ecnomy. This method has been suggested not merely as analternative to the positivist geography, but also as a theoretical foundation for critical analysis of space. The political economy of space with has analyzed the capitalist space and tried to theorize its transformation may be seen either as following humanistic(or Hegelian) Marxism, such as represented in Lefebvre's work, or as following structuralist Marxism, such as developed in Castelles's or Harvey's work. The spatial theory following humanistic Marxism has argued for a dialectic relation between 'the spatial' and 'the social', and given more attention to practicing human agents than to explaining social structures. on the contray, that based on structuralist Marxism has argued for social structures producing spatial phenomena, and focused on theorising the totality of structures, Even though these two perspectives tend more recently to be convergent in a way that structuralist-Marxist. geographers relate the domain of economic and political structures with that of action in their studies of urban culture and experience under capitalism, the political ecnomy of space needs an integrated method with which one can overcome difficulties of orthhodox Marxism. Some novel works in philosophy and social theory have been developed since the end of 1970s which have oriented towards an integrated method relating a series of concepts of action and structure, and reconstructing historical materialism. They include Giddens's theory of structuration, foucault's geneological analysis of power-knowledge, and Habermas's theory of communicative action. Ther are, of course, some fundamental differences between these works. Giddens develops a theory which relates explicitly the domain of action and that of structure in terms of what he calls the 'duality of structure', and wants to bring time-space relations into the core of social theory. Foucault writes a history in which strategically intentional but nonsubjective power relations have emerged and operated by virtue of multiple forms of constrainst wihthin specific spaces, while refusing to elaborate any theory which would underlie a political rationalization. Habermas analyzes how the Western rationalization of ecnomic and political systems has colonized the lifeworld in which we communicate each other, and wants to formulate a new normative foundation for critical theory of society which highlights communicatie reason (without any consideration of spatial concepts). On the basis of the above consideration, this paper draws a new norizon of method in human geography and spatial theory, some essential ideas of which can be summarized as follows: (1) the concept of space especially in terms of its relation to sociery. Space is not an ontological entity whch is independent of society and has its own laws of constitution and transformation, but it can be produced and reproduced only by virtue of its relation to society. Yet space is not merlely a material product of society, but also a place and medium in and through which socety can be maintained or transformed.(2) the constitution of space in terms of the relation between action and structure. Spatial actors who are always knowledgeable under conditions of socio-spatial structure produce and reproduce their context of action, that is, structure; and spatial structures as results of human action enable as well as constrain it. Spatial actions can be distinguished between instrumental-strategicaction oriented to success and communicative action oriented to understanding, which (re)produce respectively two different spheres of spatial structure in different ways: the material structure of economic and political systems-space in an unknowledged and unitended way, and the symbolic structure of social and cultural life-space in an acknowledged and intended way. (3) the capitalist space in terms of its rationalization. The ideal development of space would balance the rationalizations of system space and life-space in a way that system space providers material conditions for the maintainance of the life-space, and the life-space for its further development. But the development of capitalist space in reality is paradoxical and hence crisis-ridden. The economic and poltical system-space, propelled with the steering media like money, and power, has outstriped the significance of communicative action, and colonized the life-space. That is, we no longer live in a space mediated communicative action, but one created for and by money and power. But no matter how seriously our everyday life-space has been monetalrized and bureaucratised, here lies nevertheless the practical potential which would rehabilitate the meaning of space, the meaning of our life on the Earth.

• 정보처리학회논문지B
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• 제16B권5호
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• pp.341-346
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• 2009

모션 데이터 글러브는 손의 움직임을 측정하여 컴퓨터에 입력하는 대표적인 인간과 컴퓨터간의 인터페이스 도구로서, 홈 오토에이션, 가상 현실, biometrics, 모션 캡쳐 등의 컴퓨터 신기술에 사용되는 필수 장비이다. 본 논문에서는 대중화를 위하여, 별도의 특수 장비 없이 사용 가능한 저가형 비주얼 모션 데이터 글러브를 개발하고자 한다. 본 방식의 특징은 기존의 모션 데이터 글러브에 사용되었던, 고가의 모션 센싱 섬유를 사용하지 않음으로써, 저가형으로 개발이 가능하다는 것이다. 따라서 제작이 용이하고 대중화에 크게 기여할 수 있다는 장점을 가진다. 본 방식에서는 모션 센싱 섬유를 사용하는 기계적인 방식대신 광학적 모션 캡쳐 기술을 개량한 비주얼 방식을 채택한다. 기존의 비주얼 방식에 비해 본 방식은 다음과 같은 장점과 독창성을 가진다. 첫째, 기존의 비주얼 방식은 가려짐 현상을 제거하고 3차원 자세 복원을 위해 많은 수의 카메라와 장비를 사용하는 데 비해, 본 방식은 모노비전 방식을 채택하여 장비가 간소하고 저가형 개발이 가능하다. 둘째, 기존의 모노비전방삭은 가려짐 현상에 취약하여 영상에서 가려진 부분은 3차원 자세 복원이 어려웠다. 하지만 본 논문은 독창적으로 설계된 막대 모양의 지시자를 사용하여, 영상에서 가려진 부분도 3차원 자세 복원이 가능하다. 셋째, 기존의 모노 비전 방식은 비선형 수치해석 형태의 영상 해석 알고리즘을 사용하는 경우가 많아서 초기화나 계산시간 면에서 불편하였다. 하지만, 본 논문에서는 독창적인 공식화 방법을 사용하여 닫힌 형태의 영상해석 알고리즘을 도출함으로써 이와 같은 불편을 개선하였다. 넷째, 기존의 닫힌 형태의 알고리즘은 공식화 과정에서 근사화 방법을 도입하는 경우가 많아서 정확도가 떨어지고 특이점에 의한 응용분야에 제한이 있었다. 하지만 본 방식은 오일러 각과 같은 국부적인 매개화나 근사화 등을 사용하는 대신 지수형태의 트위스트좌표계를 사용하는 독창적인 공식화 방법을 사용하여, 공식화 단계에서의 근사화 방법 없이 닫힌 형태의 알고리즘을 도출함으로써 이 문제들을 개선하였다.

• 공업화학
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• 제29권1호
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• pp.81-96
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• 2018

본 연구에서는 천연 소재인 경옥가루의 물리화학적 특성을 조사하고 이를 함유한 워시오프 팩과 리퀴드 파운데이션을 제조하였다. 또한 이들 제형을 대상으로 각 제형이 주는 효과와 사용자 관능 평가, 제형 안정성 및 피부 안전성 평가를 수행하였다. 워시오프 팩 중의 경옥가루의 함량이 증가할수록 원적외선 방사율과 방사에너지 값이 증가하였고, 경옥가루를 3% 함유한 제품에서는 피부 적용 시 피부 온도가 약 $0.5^{\circ}C$ 상승하였다. 경옥가루를 첨가한 리퀴드 파운데이션은 피부 본래의 색을 더욱 선명하게 표현할 수 있는 채도를 나타냈다. 경옥가루를 첨가한 워시오프 팩과 리퀴드 파운데이션은 각각의 수분 보유량이 최대 5.0% 및 63.0%로 나타났다. 사용자 관능 평가에서 경옥가루를 함유한 워시오프 팩 제형은 피부친화력, 밀착력, 가려움 및 촉촉함을 개선시켰다. 경옥가루를 함유한 리퀴드 파운데이션도 대조군 제형과 비교했을 때 커버력을 제외한 모든 항목에서 개선이 이루어졌다. 경옥가루 함유 제형에 대해 8주간 안정성 평가를 한 결과 육안상으로 변색이나 분리현상은 관찰되지 않았으며 pH는 8주까지, 점도는 4주까지 안정함을 확인하였다. 또한, 피부 안전성 평가에서 경옥가루 함유 제형은 모두 자극이 없는 것으로 나타났다. 결론적으로, 경옥가루는 무기안료로써 안정성과 안전성이 확보된 새로운 다기능 소재로써 화장품에 응용 가능성이 있음을 시사하였다.

• 한국작물학회지
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• 제68권4호
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• pp.422-430
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• 2023

우리나라 국민들에게 부족하기 쉬운 영양소인 칼슘함량이 풍부하고 항산화 활성이 높은 손가락조의 기능성 식품소재로서의 가능성을 확인하고자 손가락조 '핑거1호'를 이용하여 쿠키 가공을 하였을 때 품질 특성 및 칼슘 함량 등의 변화를 평가하여 신작물인 손가락조를 이용한 가공품 개발에 활용 여부를 판단하였다. 1) 밀가루 100%를 대조로하여 핑거1호 통곡 분말 10%, 30%, 50%, 100%를 첨가하여 쿠키를 제조하고 가공 특성과 이화학 특성 등, 품질과 항산화 활성 등을 조사하였다. 2) 핑거1호 분말 첨가량이 증가함에 따라 칼슘 함량은 10% 첨가시 1.8배에서 100%시 10.8배에 이르기까지 현저하게 증가하였다. 3) 반면, 나트륨의 경우 10% 첨가시 1.01배에서 100%시 1.38배로 증가량의 변화가 크지 않아 칼슘이 부족하고 나트륨은 과다섭취하는 우리나라 국민들의 식습관을 고려할 시 영양학적으로 바람직한 쿠키의 제조가 가능할 것으로 판단되었다. 4) 항산화활성도 칼슘 등 무기성분 함량증가와 마찬가지로 핑거1호 첨가량의 증가에 ABTS radical 소거활성 1.6~7.5배, DPPH radical 소거활성 2.8~18.7배 증가하였다. 5) 쿠키의 품질특성에서 핑거1호 분말첨가가 증가할수록 쿠키의 퍼짐성은 증가하고 경도가 감소되어 부드러운 조직감의 쿠키제조가 가능하였고, 색상도 10%의 첨가만으로도 뚜렷한 차이를 나타내었다.

• Asia pacific journal of information systems
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• 제23권4호
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• pp.53-84
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• 2013

With rapid development of ICT (Information and Communications Technology), new services by the convergence of mobile network and application technology began to appear. Today, smart phone with new ICT convergence network capabilities is exceedingly popular and very useful as a new tool for the development of business opportunities. Previous studies based on Technology Acceptance Model (TAM) suggested critical factors, which should be considered for acquiring new customers and maintaining existing users in smart phone market. However, they had a limitation to focus on technology acceptance, not value based approach. Prior studies on customer's adoption of electronic utilities like smart phone product showed that the antecedents such as the perceived benefit and the perceived sacrifice could explain the causality between what is perceived and what is acquired over diverse contexts. So, this research conceptualizes perceived value as a trade-off between perceived benefit and perceived sacrifice, and we need to research the perceived value to grasp user's continuous intention to use of smart phone. The purpose of this study is to investigate the structured relationship between benefit (quality, usefulness, playfulness) and sacrifice (technicality, cost, security risk) of smart phone users, perceived value, and continuous intention to use. In addition, this study intends to analyze the differences between two subgroups of smart phone users by the degree of personal innovativeness. Personal innovativeness could help us to understand the moderating effect between how perceptions are formed and continuous intention to use smart phone. This study conducted survey through e-mail, direct mail, and interview with smart phone users. Empirical analysis based on 330 respondents was conducted in order to test the hypotheses. First, the result of hypotheses testing showed that perceived usefulness among three factors of perceived benefit has the highest positive impact on perceived value, and then followed by perceived playfulness and perceived quality. Second, the result of hypotheses testing showed that perceived cost among three factors of perceived sacrifice has significantly negative impact on perceived value, however, technicality and security risk have no significant impact on perceived value. Also, the result of hypotheses testing showed that perceived value has significant direct impact on continuous intention to use of smart phone. In this regard, marketing managers of smart phone company should pay more attention to improve task efficiency and performance of smart phone, including rate systems of smart phone. Additionally, to test the moderating effect of personal innovativeness, this research conducted multi-group analysis by the degree of personal innovativeness of smart phone users. In a group with high level of innovativeness, perceived usefulness has the highest positive influence on perceived value than other factors. Instead, the analysis for a group with low level of innovativeness showed that perceived playfulness was the highest positive factor to influence perceived value than others. This result of the group with high level of innovativeness explains that innovators and early adopters are able to cope with higher level of cost and risk, and they expect to develop more positive intentions toward higher performance through the use of an innovation. Also, hedonic behavior in the case of the group with low level of innovativeness aims to provide self-fulfilling value to the users, in contrast to utilitarian perspective, which aims to provide instrumental value to the users. However, with regard to perceived sacrifice, both groups in general showed negative impact on perceived value. Also, the group with high level of innovativeness had less overall negative impact on perceived value compared to the group with low level of innovativeness across all factors. In both group with high level of innovativeness and with low level of innovativeness, perceived cost has the highest negative influence on perceived value than other factors. Instead, the analysis for a group with high level of innovativeness showed that perceived technicality was the positive factor to influence perceived value than others. However, the analysis for a group with low level of innovativeness showed that perceived security risk was the second high negative factor to influence perceived value than others. Unlike previous studies, this study focuses on influencing factors on continuous intention to use of smart phone, rather than considering initial purchase and adoption of smart phone. First, perceived value, which was used to identify user's adoption behavior, has a mediating effect among perceived benefit, perceived sacrifice, and continuous intention to use smart phone. Second, perceived usefulness has the highest positive influence on perceived value, while perceived cost has significant negative influence on perceived value. Third, perceived value, like prior studies, has high level of positive influence on continuous intention to use smart phone. Fourth, in multi-group analysis by the degree of personal innovativeness of smart phone users, perceived usefulness, in a group with high level of innovativeness, has the highest positive influence on perceived value than other factors. Instead, perceived playfulness, in a group with low level of innovativeness, has the highest positive factor to influence perceived value than others. This result shows that early adopters intend to adopt smart phone as a tool to make their job useful, instead market followers intend to adopt smart phone as a tool to make their time enjoyable. In terms of marketing strategy for smart phone company, marketing managers should pay more attention to identify their customers' lifetime value by the phase of smart phone adoption, as well as to understand their behavior intention to accept the risk and uncertainty positively. The academic contribution of this study primarily is to employ the VAM (Value-based Adoption Model) as a conceptual foundation, compared to TAM (Technology Acceptance Model) used widely by previous studies. VAM is useful for understanding continuous intention to use smart phone in comparison with TAM as a new IT utility by individual adoption. Perceived value dominantly influences continuous intention to use smart phone. The results of this study justify our research model adoption on each antecedent of perceived value as a benefit and a sacrifice component. While TAM could be widely used in user acceptance of new technology, it has a limitation to explain the new IT adoption like smart phone, because of customer behavior intention to choose the value of the object. In terms of theoretical approach, this study provides theoretical contribution to the development, design, and marketing of smart phone. The practical contribution of this study is to suggest useful decision alternatives concerned to marketing strategy formulation for acquiring and retaining long-term customers related to smart phone business. Since potential customers are interested in both benefit and sacrifice when evaluating the value of smart phone, marketing managers in smart phone company has to put more effort into creating customer's value of low sacrifice and high benefit so that customers will continuously have higher adoption on smart phone. Especially, this study shows that innovators and early adopters with high level of innovativeness have higher adoption than market followers with low level of innovativeness, in terms of perceived usefulness and perceived cost. To formulate marketing strategy for smart phone diffusion, marketing managers have to pay more attention to identify not only their customers' benefit and sacrifice components but also their customers' lifetime value to adopt smart phone.