• Wind and Structures
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• 제2권3호
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• pp.133-150
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• 1999

Significant costs to the public and private sectors due to recent extreme wind events have motivated the need for systematic post-hurricane damage data collection and analysis. Current post disaster data are collected by many different interested groups such as government agencies, voluntary disaster relief agencies, representatives of media companies, academicians and companies in the private sector. Each group has an interest in a particular type of data. However, members of each group collect data using different techniques. This disparity in data is not conducive to quantifying damage data and, therefore, inhibits the statistical and spatial description of damage and comparisons of damage among different extreme wind events. The data collection does not allow comparisons of data or results of analyses within a group and also prohibits comparison of damage data and information among different groups. Typically, analyses of data from a given event lead to different conclusion depending upon the definition of damage used by individual investigators and the type of data collected making it difficult for members of groups to compare the results of their analyses with a common language and basis. A formal method of data collection and analysis-within any single group-would allow comparisons to be made among different individuals, hazardous events and eventually among different groups, thus facilitating the management and reduction of damage due to future disaster. This research introduces a definition of damage to single family dwellings, and a common method of data collection and analysis suited for groups interested in regional characterization of damage. The current state-of-data is presented and a method for data collection is recommended based on these existing data collection methods. A fixed-scale damage index is proposed to consider the damage to a dwelling's feature. Finally, the damage index is applied to three dwellings damaged by Hurricane Iniki (1992). The damage index reflects the reduced functionality of a structure as a single family detached dwelling and provides a means to evaluate regional damage due to a single event or to compare damage due to events of different severity. Evaluation of the damage index and the data available support recommendation for future data collection efforts.

• East Asian mathematical journal
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• 제36권5호
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• pp.537-545
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• 2020

We investigate some polynomial invariants for virtual knots via virtualization moves. We define two types of polynomials W_G(t) and S²_G(t) from the definition of the index polynomial for virtual knots. And we show that they are invariants for virtual knots on the quotient ring Z[t^±1]/I where I is an ideal generated by t² - 1.

• Communications for Statistical Applications and Methods
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• 제19권5호
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• pp.743-750
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• 2012

In this study, we propose definitions for the one-sided variance for asymmetric distribution. We consider to apply the one-sided variance to the construction to define modified $C_{pk}$, which is a definition for the process capability index for the asymmetric process distribution. Then we consider to obtain the consistent estimation for the one-sided variance and to apply to the various industrial fields.

• 대한토목학회논문집
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• 제42권4호
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• pp.457-467
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• 2022

가뭄은 지역적 특성이 강하게 나타나므로 가뭄이 진행하는 상태나 심한 정도를 정의할 수 있는 객관적인 정의나 기준이 필요하다. 이를 위해 가뭄지수(drought index)란 개념은 증발산량을 정량적으로 제시하면서 시작되었으며, 현재까지 전 세계적으로 많은 가뭄 관련 연구가 수행되고 있다. 본 연구에서는 대표적인 기상학적 가뭄지수인 표준 강수 지수(SPI)를 산정하였고, 실질적인 가뭄을 고려할 수 있는 가뭄 위험 지수(DRI)를 가뭄 취약성 지수(DVI)와 가뭄 위험요소 지수(DHI)를 대상지역인 의령군에 적용하여 안정적인 용수공급 체계를 마련할 수 있는 실제적인 가뭄의 평가에 대한 방법을 제시하였다.

• 대한지역사회영양학회지
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• 제29권1호
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• pp.34-50
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• 2024

Objectives: Transformation through a sustainable food system to provide healthy diets is essential for enhancing both human and planetary health. This study aimed to explain about sustainable diets and illustrate appropriate measurement of adherence to sustainable diets using a pre-existing index. Methods: For literature review, we used PubMed and Google Scholar databases by combining the search terms "development," "validation," "sustainable diet," "sustainable diet index," "planetary healthy diet," "EAT-Lancet diet," and "EAT-Lancet reference diet." For data presentation, we used data from National Health and Nutrition Examination Survey, 2017-2018, among adults aged 20 years and older (n = 3,920). Sustainable Diet Index-US (SDI-US), comprising four sub-indices corresponding to four dimensions of sustainable diets (nutritional quality, environmental impacts, affordability, and sociocultural practices), was calculated using data from 24-hour dietary recall interview, food expenditures, and food choices. A higher SDI-US score indicated greater adherence to sustainable diets (range: 4-20). This study also presented SDI-US scores according to the sociodemographic status. All analyses accounted for a complex survey design. Results: Of 148 papers, 16 were reviewed. Adherence to sustainable diets fell into 3 categories: EAT-Lancet reference diet-based (n = 8), Food and Agriculture Organization (FAO) definition-based (n = 4), and no specific guidelines but including the sustainability concept (n = 4). Importantly, FAO definition emphasizes on equal importance of four dimensions of diet (nutrition and health, economic, social and cultural, and environmental). The mean SDI-US score was 13 out of 20 points, and was higher in older, female, and highly educated adults than in their counterparts. Conclusions: This study highlighted that sustainable diets should be assessed using a multidimensional approach because of their complex nature. Currently, SDI can be a good option for operationalizing multidimensional sustainable diets. It is necessary to develop a Korean version of SDI through additional data collection, including environmental impact of food, food price, food budget, and use of ready-made products.

• Asian Journal of Innovation and Policy
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• 제2권1호
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• pp.37-62
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• 2013

Many scholars have persevered in understanding the convergence process by developing a measurement that reflects the characteristics of the convergence phenomenon as a process. Recently a series of studies suggested a framework in terms of diversity and coherence. However, an index for coherence is required to reflect the vital features of the conceptual definition, and thus a new index for coherence is proposed in this paper. Technology Convergence Index combines diversity and coherence and indicates the degree of the convergence in information computer technology (ICT), biotechnology (BT) and nanotechnology (NT) sectors. The index can not only be used to track each technology field that consists of a major technology sector, but also to compare other leading countries. Based on a comparison study between the United States and South Korea, the degrees of technology convergence of Korea in ICT, BT, and NT sectors have ameliorated.

• 대한기계학회논문집A
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• 제24권4호
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• pp.811-823
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• 2000

In design and manufacturing airframe structures which are composed of a lot of sub-assemblies and large complex profile shapes it is difficult to reduce so called hardware variations. Accordingly cost increasing factors for manufacturing airframe parts are much more than other machine parts because of the variability of fabricated details and assemlies. To improve cost and quality, accurate assembly methods and DPD techniques are proposed in this paper which are based upon using CAD/CAM techniques, the concept of KC's and the coordinated datum and index throughout the design, tooling, manufacturing and inspection. The proposed methods are applied to produce fuselage frame assemblies and related engineering aspects are described regarding the design of parts and tools in the context of concurrent digital definition. First articles and consequent mass production of frame assemblies shows a great improvement of the process capability ratio from 0.7 by the past processes to 1.0 by the proposed methods in addition to the cost reduction due to the less number of tools, reduced total assembly times and the space compaction needed by massive inventory. The need to achieve better Cpk, however, and future studies to be investigated will be addressed briefly.

• Structural Engineering and Mechanics
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• 제62권3호
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• pp.365-372
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• 2017

Reliability analysis is a probabilistic approach to determine a safety level of a system. Reliability is defined as a probability of a system (or a structure, in structural engineering) to functionally perform under given conditions. In the 1960s, Basler defined the reliability index as a measure to elucidate the safety level of the system, which until today is a commonly used parameter. However, the reliability index has been formulated based on the pivotal assumption which assumed that the considered limit state function is normally distributed. Nevertheless, it is not guaranteed that the limit state function of systems follow as normal distributions; therefore, there is a need to define a new reliability index for no-normal distributions. The main contribution of this paper is to define a sophisticated reliability index for limit state functions which their distributions are non-normal. To do so, the new definition of reliability index is introduced for non-normal limit state functions according to the probability functions which are calculated based on the convolution theory. Eventually, as the state of the art, this paper introduces a simplified method to calculate the reliability index for non-normal distributions. The simplified method is developed to generate non-normal limit state in terms of normal distributions using series of Gaussian functions.

• 전기학회논문지
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• 제59권11호
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• pp.1996-2005
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• 2010

This paper proposes a new method for constant control of the output AC voltage of a voltage-fed three phase Z-source inverter (ZSI), in case of Z-network DC voltage variation or heavy change of load. The modulation index for the reference output AC voltage of ZSI can be calculated by the basic definition of ZSI, the input DC voltage and capacitor voltage of Z-network. And, the output AC voltage of ZSI is controlled by the modified space vector modulation (SVM) with the calculated modulation index. By the proposed method, the modulation index of output AC voltage is closely following in the reference modulation index. The validity of the proposed method is verified using PSIM simulation. In case which the input DC voltage of ZSI is heavily changed from 100[V] to 70[V] (or to 150[V]) and in case which load is changed from $30[\Omega]$ to $10[\Omega]$, we confirmed that the output AC voltage of ZSI is constantly controlled by the proposed method because the modulation index of ZSI is also simultaneously changed. Finally, FFT and %THD of the output voltage and current of ZSI by the proposed method are analyzed.

• 대한기계학회논문집A
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• 제26권1호
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• pp.74-82
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• 2002

In this paper the start fuel index was developed to estimate ride quality of a forklift truck during the start motion. Through the consultation with test drivers, definition of start feel was made, and three parameters were selected to describe the start motion. They are engagement shock in the forwarding direction, vertical and pitch vibration respectively. To find out the relation between the measured motion and the subjective fueling, both the subjective rating and the measurement of vehicle motions were performed simultaneously. The correlation analysis between the two kinds of results showed start fuel was expressed by the measured accelerations with accuracy and reliability, Use of the new index has advantages of not only evaluating start fuel only by the measured signals but providing the consistent results which are not affected by physical and mental state of a test driver. Usefulness of the new index was confirmed by verification test on four new forklift trucks of a same model, which showed the order of preference by the index was coincided that by subjective evaluation.