• Title/Summary/Keyword: Unexpected values

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Seismic performance of a building base-isolated by TFP susceptible to pound with a surrounding moat wall

  • Movahhed, Ataallah Sadeghi;Zardari, Saeid;Sadoglu, Erol
    • Earthquakes and Structures
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    • v.23 no.1
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    • pp.87-100
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    • 2022
  • Limiting the displacement of seismic isolators causes a pounding phenomenon under severe earthquakes. Therefore, the ASCE 7-16 has provided minimum criteria for the design of the isolated building. In this research the seismic response of isolated buildings by Triple Friction Pendulum Isolator (TFPI) under the impact, expected, and unexpected mass eccentricity was evaluated. Also, the effect of different design parameters on the seismic behavior of structural and nonstructural elements was found. For this, a special steel moment frame structure with a surrounding moat wall was designed according to the criteria, by considering different response modification coefficients (RI), and 20% mass eccentricity in one direction. Then, different values of these parameters and the damping of the base isolation were evaluated. The results show that the structural elements have acceptable behavior after impact, but the nonstructural components are placed in a moderate damage range after impact and the used improved methods could not ameliorate the level of damage. The reduction in the RI and the enhancement of the isolator's damping are beneficial up to a certain point for improving the seismic response after impact. The moat wall reduces torque and maximum absolute acceleration (MAA) due to unexpected enhancement of mass eccentricity. However, drifts of some stories increase. Also, the difference between the response of story drift by expected and unexpected mass eccentricity is less. This indicates that the minimum requirement displacement according to ASCE 7-16 criteria lead to acceptable results under the unexpected enhancement of mass eccentricity.

A new geophysical exploration method based on electrical resistivity to detect underground utility lines and geological anomalies: Theory and field demonstrations

  • Jo, Seon-Ah;Kim, Kyoung-Yul;Ryu, Hee-Hwan
    • Geomechanics and Engineering
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    • v.18 no.5
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    • pp.527-534
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    • 2019
  • Although ground investigation had carried out prior to the construction, many problems have arisen during the civil-engineering works because of the presence of the unexpected underground utility lines or anomalies. In this study, a new geophysical exploration method was developed to solve those problems by improving and supplementing the existing methods. This new method was based on the difference of electrical resistance values between anomalies and surrounding ground medium. A theoretical expression was suggested to define the characteristics of the anomalies such as location, size and direction, by applying the electric field analysis. An inverse analysis algorithm was also developed to solve the theoretical expression using the measured electrical resistance values which were generated by the voltage flowing the subsurface medium. To verify the developed method, field applications were conducted at the sites under construction or planned. From the results of the field tests, it was found that not only the new method was more predictive than the existing methods, but its results were good agreed with the measured ones. Therefore, it is expected that application of the new exploration method reduces the unexpected accidents caused by the underground uncertainties during the underground construction works.

The Impacts of Changes in Brand Attributes on Financial Market Valuation of Korean Firms

  • Lee, Hee Tae;Kim, Byung-Do
    • Asia Marketing Journal
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    • v.16 no.1
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    • pp.169-193
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    • 2014
  • The earlier studies have verified that brand values have significant impact on financial values such as stock return and stock price to justify marketing costs for brand building. Except for Mizik and Jacobson (2008), however, little research has addressed what kinds of brand components composing brand values have a significant relationship with financial values. As a follow-up research of Mizik and Jacobson (2008), this research focuses on what kinds of relationships exist between the unanticipated change of each brand asset component and stock return, one of the financial values. The authors selected six brand asset components from the Korea-Brand Power Index(K-BPI) data in which 'Top of Mind,' 'Unaided Awareness,' and 'Aided Awareness' are brand awareness measures and 'Image,' 'Purchase Intention,' and 'Preference' are brand loyalty measures. Out of those six brand components, they found that unanticipated changes of 'Top of Mind,' 'Unaided Awareness,' 'Image,' and 'Preference' have significantly positive effect on unexpected stock return change. Therefore, they conclude that these four brand asset components provide incremental information in explaining unanticipated stock return.

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Power System State Estimation and Identification in Consideration of Line Switching (선로개폐상태를 포함하는 전력통계 상태추정및 동정)

  • 박영문;유석한
    • 전기의세계
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    • v.28 no.3
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    • pp.57-64
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    • 1979
  • The static state estimation are divided into two groups; estimation and detection & identification. This paper centers on detection and identification algorithm. Especially, the identification of line errors is focused on and is performed by the extended W.L.S. algorithm with line swithching states. Here, line switching states mean the discrete values of line admittance which are influenced by unexpected line switching. The numerical results are obtained from the assumption that the noise vector is independent zero mean Gaussian random variables.

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Development of Diagnosis Expert System for Production Facility by using CBR (사례베이스추론에 의한 생산설비의 고장진단 전문가시스템의 개발)

  • 김광만;이재원
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.18 no.34
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    • pp.25-33
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    • 1995
  • An expert system DESPRESS is developed to diagnose the fault of press by using CBR technique. In this paper, we describes the subjects for development of the system. DESPRESS deals compositly with perceptive symptoms, functional abnormalities, lamp signals and gage values, and then outputs fault parts and fault status for the press. The expert system can be used to prevent occurance of unexpected fault and minimize break times for failures.

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Validation of chlorophyll algorithm in Ulleung Basin, East/Japan Sea

  • Yoo, Sin-Jae;Kim, Hyun-Cheol;Lee, Jeong-ah;Park, Mi-Ok
    • Korean Journal of Remote Sensing
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    • v.18 no.1
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    • pp.35-42
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    • 2002
  • The results of our observation in May 2000 indicated that the SeaWiFS algorithm (O'Reilley et al., 1998), which was adopted for OSMI data processing, overestimated the actual chlorophyll values. This was rather unexpected in that there were good reasons to expect that the bio-optical properties of East/Japan Sea belonged to Case 1 water and in such case, the OC2 algorithm would give unbiased estimates of actual chlorophyll a values. In November 2000, a cruise conducted bio-optical surveys in the same area. This time we added HPLC (High Performance Liquid Chromatography) method for measuring chlorophyll a concentration to the standard fluorometric method, which we hale been using during the past Fluorometric method with acidification is known to result in under/overestimation of chlorophyll values in many parts of the world oceans, while it is easier and cheaper than HPLC method. To our surprise, the comparison of HPLC chlorophyll and fluorometric chlorophyll values show that fluorometric values gave an underestimation up to 50%. This error was due to the presence of accessory pigments such as chlorophyll b. Considering this error, our precious result of May 2000(Yoo et al., 2000) might have to be reinterpreted. Calculation of reflectance at 490 and 555nm, however, indicated that this is not still enough to explain the discrepancies.

An Empirical Study on the Stock Volatility of the Korean Stock Market (한국 증권시장의 주가변동성에 관한 실증적 연구)

  • Park, Chul-Yong
    • Korean Business Review
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    • v.16
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    • pp.43-60
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    • 2003
  • There are several stylized facts concerning stock return volatility. First, it is persistent, so an increase in current volatility lasts for many periods. Second, stock volatility increases after stock prices fall. Third, stock volatility is related to macroeconomic volatility, recessions, and banking crises. On the other hand, there are many competing parametric models to represent conditional heteroskedasticity of stock returns. For this article, I adopt the strategy followed by French, Schwert, and Stambaugh(1987) and Schwert(l989, 1990). The models in this article provide a more structured analysis of the time-series properties of stock market volatility. Briefly, these models remove autoregressive and seasonal effects from daily returns to estimate unexpected returns. Then the absolute values of the unexpected returns are used in an autoregressive model to predict stock volatility.

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Pre-service Elementary Teachers Difficulties in Science Lessons (초등 예비교사들이 과학 수업에서 겪는 어려움)

  • 윤혜경
    • Journal of Korean Elementary Science Education
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    • v.23 no.1
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    • pp.74-84
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    • 2004
  • The purpose of this study was to get an implication on teacher education program, by exploring the difficulties pre-service elementary teachers have with their science lessons. 37 pre-service teachers were requested to write an anecdote about their science lessons during their 4 week practicum. By analyzing these anecdotes, the difficulties were grouped into several categories by the researcher, and then reconfirmed by the pre-service teachers themselves. The result showed that there were far more difficulties with practical work (cases: 48), than with content knowledge teaching (cases: 17). Among practical work related difficulties, the most frequent cases were: 1) when they have unexpected result different from scientific theory (cases: 10), 2) when they teach process skill and usage of lab equipments (cases: 8), and 3) when they do not have enough preparation for practical work (cases: 7). Unlike the result of preceding research on secondary pre-service teachers, there was no affective aspect problems. These difficulties also can be divided into 'problems' and 'dilemmas'. Whereas 'problems' can be settled by removing obstacles, 'dilemmas', a conflict-filled situation, require choices between competing values or aims. The use of scientific language, the decision on the level and amount of knowledge they teach, and disposal of unexpected experiment results caused such dilemmas in science lessons. The research results imply practical work should be more strengthened in the elementary teacher education program. And both teacher educators and pre-service teachers need to understand that practical teaching is a complex enterprise accompanying some 'dilemmas'. The role of science teachers as managers of dilemmas could be considered.

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Fashion Styles and Aesthetic Values represented in Bridesmaid dresses - Focused on Movie '27 Dresses' -

  • Kim, Young Sam;Lee, Jin-Ah
    • Fashion & Textile Research Journal
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    • v.16 no.6
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    • pp.860-870
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    • 2014
  • This study considers style types and examines aesthetic values by analyzing images expressed through bridesmaid dresses in the movie '27 Dresses'. The research method used was a case study on fashion types from movie costumes. The conclusions of this study are as follows. There are three fashion style types in the movie '27 Dresses' presented by diverse dress type according the bride's dress code, dress style that reflects a country's culture and tradition of how bridesmaids wear traditional costumes particular to each country as well as a dress style that suits the overall wedding's atmosphere and theme. The aesthetic values of the movie '27 Dresses': First, it reflects a complementarity synergy between the bridesmaid and the bride at the wedding. It plays a complementary role in creating synergy through a harmonious presentation at the wedding. Secondly, it represents traditionality. Traditional costumes of different cultures were used as bridesmaid dresses. These costumes play an important role in denoting the bride's nationality and tradition. Third, it represents a sense of amusement using a wedding as concept. The bridesmaid dresses were unique in a way that elicited surprise and unexpected laughter as well as a feeling of pleasure and interest in the audience. The different styles of bridesmaid dresses in movie costumes can help expand more diverse wedding cultures in a modern society.