• Asia pacific journal of information systems
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• 제23권4호
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• pp.85-102
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• 2013

This study proposes a web presence readiness model based on pre-payment service functions and a post-payment service function both of which embrace the major concerns of customers in the online purchasing context. Based on the concept of customer utility from the product itself and instrumental utility, the research model suggests four antecedents including, Perceived Economic Benefits, Product Search Support Quality, e-Shopping Method Diversity, and Post-Payment Support Quality. We empirically examined a proposed research model using data collected from online rating company websites. Among the four antecedents, post payment support quality is found to be the most influential determinant of customer evaluation on e-commerce websites. Based on the empirical results, the current study proposes an alternate model of web presence readiness. The findings of this study may provide an insight to field practitioners designing commercial websites. The implications and future research directions are further discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.24-45
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• 2012

In this paper, we present a survey of security and privacy preserving issues in M2M communications in Cyber-Physical Systems. First, we discuss the security challenges in M2M communications in wireless networks of Cyber-Physical Systems and outline the constraints, attack issues, and a set of challenges that need to be addressed for building secure Cyber-Physical Systems. Then, a secure architecture suitable for Cyber-Physical Systems is proposed to cope with these security issues. Eventually, the corresponding countermeasures to the security issues are discussed from four aspects: access control, intrusion detection, authentication and privacy preserving, respectively. Along the way we highlight the advantages and disadvantages of various existing security schemes and further compare and evaluate these schemes from each of these four aspects. We also point out the open research issues in each subarea and conclude with possible future research directions on security in Cyber-Physical Systems. It is believed that once these challenges are surmounted, applications with intrinsic security considerations will become immediately realizable.

• Wind and Structures
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• 제32권3호
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• pp.249-265
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• 2021

As high-rise buildings become more and more slender and flexible, the wind effect has become a major concern to modern buildings. At present, wind engineering for high-rise buildings mainly focuses on the following four issues: wind excitation and response, aerodynamic damping, aerodynamic modifications and proximity effect. Taking these four issues of concern in high-rise buildings as the mainline, this paper summarizes the development history and current research progress of wind engineering for high-rise buildings. Some critical previous work and remarks are listed at the end of each chapter. From the future perspective, the CFD is still the most promising technique for structural wind engineering. The wind load inversion and the introduction of machine learning are two research directions worth exploring.

• Journal of Information Science Theory and Practice
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• 제8권4호
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• pp.20-28
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• 2020

In this study, the RDA DMP Common Standard (RDCS), a data model for implementing a machine actionable Data Management Plan (maDMP), was analyzed in four aspects. First, the twelve class models proposed by RDCS were analyzed. Second, whether the DMP attribute was included in the class attribute was analyzed. Third, we analyzed the namespace used for RDCS properties. Fourth, the values and identifiers used in RDCS properties were analyzed. As a result of the analysis, four directions for improvement were derived. First, it is necessary to add an academic record class to describe information such as papers and reports, which are representative academic documents. Second, the primary research institution, responsibility, resources, option attribute, and additional attributes are needed to describe the researcher's affiliation information. Third, it is necessary to additionally use a namespace such as Friend of a Friend that can be used universally. Fourth, the use of digital object identifier should be considered to identify academic literature.

• 한국정보시스템학회지:정보시스템연구
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• 제30권1호
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• pp.105-121
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• 2021

Purpose Today, through digital services, many people enjoy a conveient and comfortable life. Nevertheless, it is easy to find people in our daily lives who are buried in work without any payment that we did not do before digital services. Such un-payed works under digital environment are called digital shadow works. The purpose of this study is to classification and dynamics of digital shadow works and to suggest research direction. Design/methodology/approach Based on two dimension, voluntary participation ('should' type and 'want' type) and work orientation (management-operation), digital shadow works were classified into four categories - chore, makeup, routine, and quest. Findings In digital shadow work there are four types of dynamics - routine and quest, makeup and chore, makeup and quest, and quest and actions in offline. According to the classification and analysis of dynamics, three research directions in digital shadow work are suggested and discussed- digital shadow works operation mechanism considering dynamics, expansion of existing user theories based on survey method by digital shadow works and social influences by digital shadow works.

• 한국초등과학교육학회지:초등과학교육
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• 제30권1호
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• pp.102-112
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• 2011

The purpose of this study is to investigate how $3^{rd}$ and $4^{th}$ grade elementary students view about 'Science story', which is recently inserted in the new version of science text books. For the study, four hundred $4^{th}$ graders at four schools were considered in the area of Cheonan city, Chungnam province. The degree of student's preference, preferable science topics from the 'Science story', the reason for their preference, and their attitudes toward general science were examined. The study was initiated after student's reading of the 'Science story' (Advanced science, Science in the life, Science in the history, and Future science directions). The student attitudes toward general science were examined using questionnaire survey prior to others. The results of the study are summarized: First, the students who have more interests and affirmative attitudes about science subjects with high scores are more favored about 'Science story'. Second, generally the students prefer reading topics in the order of 1) Science in the life, 2) Advanced science, 3) Science in the history, and 4) Future science directions. However the order was flexible depending on student's gender, preference, and attitudes. Third, the student's interests about 'Science story' was mostly raised from the new scientific topics in the book. And it was also raised partly from their personal interests and usefulness for science learning. Based on the results of our study, we included some suggestions for the improved 'Science story' and their utilizations.

• 방송공학회논문지
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• 제21권3호
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• pp.404-411
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• 2016

본 논문에서는 우리나라 FM(Frequency Modulation) 방송국에서 송신용 안테나로 사용하고 있는 CP(circularly polarized)-dipole 안테나와 CP(circularly polarized)-ring 안테나에 대해 실제 전계 강도 측정을 통한 안테나의 전파 방사 패턴을 조사하고, 현장 적용에 대해 비교 고찰하였다. 비교 결과, 송·중계소가 방송국의 방송 서비스 지역의 한 가운데에 위치하는 경우에는 CP-dipole 안테나(4방향)가 유용하며, 후방에 있는 철탑의 반사 효과로 인해 지향 특성을 갖는 CP-ring 안테나는 지향 방향의 조정을 통하여 타 지역으로의 전파 월경 방지는 물론 주요 서비스 방향으로 5∼9dB 높은 전파를 방사할 수 있었다. 특히, 송·중계소가 서비스 구역의 한 쪽 방향에 위치하여 3방향으로 전파를 방사하는 경우가 많은 우리나라에서는 CP-ring 안테나를 사용하여 안테나의 지향 방향을 인구 및 도로 밀집 지역으로 집중하여 방송 수신 환경을 개선시킬 수 있다.

• 박물관보존과학
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• 제18권
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• pp.35-50
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• 2017

국립중앙박물관 목조불상 조사사업 중 복장물에 직물이 포함된 4건 53점의 조사를 실시하였다. 조사 결과 첫째, 복장직물의 직조 방식을 구분하면 고려시대의 라직물 2점과 능직물 5점이 확인되었으며, 조선시대 특징이 나타나는 단직물과 사직물로 분류되었다. 특히 금동관음보살좌상(덕수801) 복장직물에서는 조선 전기와 후기 특징을 지닌 직물로 분류된 것으로 보아 15세기와 17세기에 2차례에 걸쳐 납입이 이루어졌을 가능성이 높다. 둘째, 직물 무늬의 종류는 꽃무늬와 보배무늬, 과실무늬, 동물이 함께 나타난 식물무늬와 구름무늬로 구성된 자연산수무늬로 구별되었다. 셋째, 복장직물의 수량은 적지만 구성에 따라 모든 방위에 해당될 것으로 추정할 수 있는 직물 편이 발견되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1184-1189
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• 1990

In order to investigate liquid fuel filming over the intake manifold wall, an electrode-type probe has been developed by lines of authors and this probe was employed in a single cylinder two and four-stroke cycle engine and in a four cylinder four-stroke engine operated by neat methanol fuel. The performance of the probe was dependent upon several parameters including the liquid fuel layer thickness, temperature, additive in the fuel, and electric power source (i.e., AC and voltage level) and was independent of other variables such as direction of liquid flow with respect to the probe arrangement. Several new findings from this study may be in order. The flow velocity of the fuel layer in the intake manifold of engine was about (if the air velocity in the steady state operation, the layer thickness of liquid fuel varied in both the circumferential and longitydinal directions. In the transient operation of the engine, the temporal variation of fuel thickness was determined, which clearly suggests that there was difference between fuel/air ratio in the intake manifold and that in the cylinder. The variation was greatly affected by the engine speed, fuel/air ratio and throttle opening. And the variation was also very significant from cylinder to cylinder and it was particularly strong different engine speeds and throttle opening.

• Smart Structures and Systems
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• 제6권7호
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• pp.793-810
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• 2010

This paper addresses the control issue of vibratory MEMS-based gyroscopes. This study considers a gyroscope that can be modeled by an inner mass attached to an outer mass by four springs and four dampers. The outer mass itself is attached to the rotating frame by an equal number of springs and dampers. In order to measure the angular rate of the rotating frame, a driving force is applied to the inner mass and the Coriolis force is sensed along the y-direction associated with the outer mass. Due to micro-fabrication imperfections, including anisoelasticity and damping effects, both gyroscopes do not allow accurate measurements, and therefore, it becomes necessary to devise feedback controllers to reduce the effects of such imperfections. Given an ideal gyroscope that meets certain performance specifications, a feedback control strategy is synthesized to reduce the error dynamics between the actual and ideal gyroscopes. For a dual-mass gyroscope, it is demonstrated that the error dynamics are remarkably decreased with the application of four actuators applied to both masses in the x and y directions. It is also shown that it is possible to reduce the error dynamics with only two actuators applied to the outer mass only. Simulation results are presented to prove the efficiency of the proposed control design.