• Title/Summary/Keyword: model of line segment

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Establishment of Maintenance and Monitoring Standards for Shield and TBM Tunnels (Shield 및 TBM 터널의 유지관리계측 관리기준 설정에 관한 연구)

  • Jong-Tae Woo
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.1-12
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    • 2024
  • Purpose: The objective of this study was to improve the tunnel maintenance and monitoring technology by establishing the maintenance, management, and monitoring standards for shield and TBM tunnels, which had been applied more in recent years. Method: This study comprehensively analyzed and compared the data and model simulations of Seoul Subway Lines 7 and 9 and Bundang Line, shield and TBM tunnels in South Korea, tunnels in France and Japan, and Channel Tunnel in the UK. Result: This study set maintenance and monitoring standards when there was no design estimate based on numerical analyses such as section design and section analysis regarding the maintenance and monitoring section of shield and TBM tunnels. Conclusion: It is necessary to determine safety by comprehensively considering not only each monitoring item but also the changing trend and correlation of all items and compensation of the tunnel.

Numerical Analysis of the Grand Circulation Process of Mang-Bang Beach-Centered on the Shoreline Change from 2017. 4. 26 to 2018. 4. 20 (맹방해빈의 일 년에 걸친 대순환과정 수치해석 - 2017.4.26부터 2018.4.20까지의 해안선 변화를 중심으로)

  • Cho, Young Jin;Kim, In Ho;Cho, Yong Jun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.3
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    • pp.101-114
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    • 2019
  • In this study, we carry out the numerical simulation to trace the yearly shoreline change of Mang-Bang beach, which is suffering from erosion problem. We obtain the basic equation (One Line Model for shoreline) for the numerical simulation by assuming that the amount of shoreline retreat or advance is balanced by the net influx of longshore and cross-shore sediment into the unit discretized shoreline segment. In doing so, the energy flux model for the longshore sediment transport rate is also evoked. For the case of cross sediment transport, the modified Bailard's model (1981) by Cho and Kim (2019) is utilized. At each time step of the numerical simulation, we adjust a closure depth according to pertinent wave conditions based on the Hallermeier's analytical model (1978) having its roots on the Shield's parameter. Numerical results show that from 2017.4.26 to 2017.10.15 during which swells are prevailing, a shoreline advances due to the sustained supply of cross-shore sediment. It is also shown that a shoreline temporarily retreats due to the erosion by the yearly highest waves sequentially occurring from mid-October to the end of October, and is followed by gradual recovery of shoreline as high waves subdue and swells prevail. It is worth mentioning that great yearly circulation of shoreline completes when a shoreline retreats due to the erosion by the higher waves occurring from mid-March to the end of March. The great yearly circulation of shoreline mentioned above can also be found in the measured locations of shoreline on 2017.4.5, 2017.9.7, 2017.11.7, 2018.3.14. However, numerically simulated amount of shoreline retreat or advance is more significant than the physically measured one, and it should be noted that these discrepancies become more substantial for the case of RUN II where a closure depth is sustained to be as in the most morphology models like the Genesis (Hanson and Kraus, 1989).

A Study on Factors Influencing Attachment of Gamers to MMORPG On-line Games (MMORPG 온라인 게이머의 애착감 영향요인 연구)

  • Park, Seong-Taek;Lee, Han-Chul;Kim, Tae-Ung;Choi, Soo-Myung
    • Journal of Digital Convergence
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    • v.10 no.2
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    • pp.109-119
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    • 2012
  • MMORPG online game business has emerged as the most lucrative entertainment industry, with over 10 million gamers in South Korea. It appears that in this extremely attractive and growing services segment, academics, as well as practitioners, would benefit from investigating the relationships among the players' attachment or affection, game contents-related and social interaction-related construct. We assume that game contents-related construct consists of storytelling, game-play method, contents-diversity and the sense of identification, and that social interaction-related construct includes information-sharing, gamers' empowerment and the word-of-mouth. Based on data collected from online questionnaire survey, the validity of the research model has been tested. The results show that contents-related construct influences the players' attachment, and that social interaction-related construct has no direct impact on the attachment. But social interaction-related construct has been shown to influence contents-related construct, implying the indirect impact on the players' attachment.

Time-Scale Modification of Polyphonic Audio Signals Using Sinusoidal Modeling (정현파 모델링을 이용한 폴리포닉 오디오 신호의 시간축 변화)

  • 장호근;박주성
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.2
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    • pp.77-85
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    • 2001
  • This paper proposes a method of time-scale modification of polyphonic audio signals based on a sinusoidal model. The signals are modeled with sinusoidal component and noise component. A multiresolution filter bank is designed which splits the input signal into six octave-spaced subbands without aliasing and sinusoidal modeling is applied to each subband signal. To alleviate smearing of transients in time-scale modification a dynamic segmentation method is applied to subbands which determines the analysis-synthesis frame size adaptively to fit time-frequency characteristics of the subband signal. For extracting sinusoidal components and calculating their parameters matching pursuit algorithm is applied to each analysis frame of subband signal. In accordance with spectrum analysis a psychoacoustic model implementing the effect of frequency masking is incorporated with matching pursuit to provide a resonable stop condition of iteration and reduce the number of sinusoids. The noise component obtained by subtracting the synthesized signal with sinusoidal components from the original signal is modeled by line-segment model of short time spectrum envelope. For various polyphonic audio signals the result of simulation shows suggested sinusoidal modeling can synthesize original signal without loss of perceptual quality and do more robust and high quality time-scale modification for large scale factor because of representing transients without any perceptual loss.

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Analysis of Foreign Customers' Price Sensitivity on Korean Traditional Restaurants Using Price Sensitivity Measurement (외국인의 한식당에 대한 가격민감성 분석)

  • Lee, Min-A
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.1
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    • pp.124-130
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    • 2007
  • The purposes of this study were (1) to analyze price sensitivity, (2) to define the range of acceptable prices for each foreign segment, and (3) to provide a price model for Korean traditional restaurants. From October to November, 2006, a total of 781 foreigners responded to individual surveys. Statistical analyses on the survey data were performed using descriptive statistics and Price Sensitivity Measurement (PSM). Major findings from the study are as follows: First, the ranges of the acceptable prices were $98$\sim$$130 for fine dining/gourmet restaurants, $70$\sim$$90 for theme/ambience restaurants, $40$\sim$$60 for popular/family restaurants, and $18$\sim$$30 for convenience/fast food restaurants. Second, the convenience/fast food restaurants showed the highest price sensitivity. Third, a low stress level and wide range of the acceptable price were observed for the fine dining/gourmet restaurants, suggesting that the price sensitivity of the fine dining/gourmet restaurants was quite low. Finally, the price sensitivity indicated by the Japanese was higher than by the other groups. In consequence, the research findings suggest that the managers of the Korean traditional restaurants should strategically plan prices by understanding different customers' price sensitivity within and between customer segments. Through additional research, marketers can compare perceptions of specific brands, the competition, and variations within a product line.

Effect of Attenuation Correction, Scatter Correction and Resolution Recovery on Diagnostic Performance of Quantitative Myocardial SPECT for Coronary Artery Disease (감쇠보정, 산란보정 및 해상도복원이 정량적 심근 SPECT의 관상동맥질환 진단성능에 미치는 효과)

  • Hwang, Kyung-Hoon;Lee, Dong-Soo;Paeng, Jin-Chul;Lee, Myoung-Mook;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.36 no.5
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    • pp.288-297
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    • 2002
  • Purpose: Soft tissue attenuation and scattering are major methodological limitations of myocardial perfusion SPECT. To overcome these limitations, algorithms for attenuation, scatter correction and resolution recovery (ASCRR) is being developed, while quantitative myocardial SPECT has also become available. In this study, we investigated the efficacy of an ASCRR-corrected quantitative myocardial SPECT method for the diagnosis of coronary artery disease (CAD). Materials and Methods: Seventy-five patients (M:F=51:24, $61.0{\pm}8.9$ years old) suspected of CAD who underwent coronary angiography (CAG) within $7{\pm}12$ days of SPECT(Group-I) and 20 subjects (M:F=10:10, age $40.6{\pm}9.4$) with a low likelihood of coronary artery disease (Group-II) were enrolled. Tl-201 rest/ dipyridamole-stress Tc-99m-MIBI gated myocardial SPECT was performed. ASCRR correction was peformed using a Gd-153 line source and automatic software (Vantage-Pro; ADAC Labs, USA). Using a 20-segment model, segmental perfusion was automatically quantified on both the ASCRR-corrected and uncorrected images using an automatic quantifying software (AutoQUANT; ADAC Labs.). Using these quantified values, CAD was diagnosed in each of the 3 coronary arterial territories. The diagnostic performance of ASCRR-corrected SPECT was compared with that of non-corrected SPECT. Results: Among the 75 patients of Group-I, 9 patients had normal CAG while the remaining 66 patients had 155 arterial lesions; 61 left anterior descending (LAD), 48 left circumflex (LCX) and 46 right coronary (RCA) arterial lesions. For the LAD and LCX lesions, there was no significant difference in diagnostic performance. In Group-II patients, the overall normalcy rate improved but this improvement was not statistically significant (p=0.07). However, for RCA lesions, specificity improved significantly but sensitivity worsened significantly with ASCRR correction (both p<0.05). Overall accuracy was the same. Conclusion: The ASCRR correction did not improve diagnostic performance significantly although the diagnostic specificity for RCA lesions improved on quantitative myocardial SPECT. The clinical application of the ASC-RR correction requires more discretion regarding cost and efficacy.

The Study of Characteristics of Consumer Purchasing Private Brand Products at Large-Scale Mart (국내 대형마트의 유통업체 브랜드 상품 구매 소비자의 특성 분석에 관한 연구)

  • Hwang, Seong-Huyk;Lee, Jung-Hee;Roh, Eun-Jung
    • Journal of Distribution Research
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    • v.15 no.4
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    • pp.1-19
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    • 2010
  • As having the movement of developing private brand (PB) goods, domestic big retailers are facing up with new problems. Thus, it is required studies of PB products, and how consumers recognize PB products as a consideration commodity set. Also, it is worthy in order that it gives us the important meaning on the marketing strategy with focusing on evaluating the differences between customers buying PB grocery goods with respect to demographic characteristics and purchasing behaviors. PB has some advantages for customers and retailers. However, according to AC Nielson's report (2005), Asian and emerging market has 1/5 sales relatively to Western countries. But we can assume that the emerging market has the most potential growth through this result. As a result from several other studies, it becomes necessary to not only increase the rate of selling composition of PB product temporarily, but also analyze the characteristics of customers using big retailers and segmenting customer groups to make PB product as a consideration commodity set for them. In addition, it is needed to have a variety of acts of marketing. From studies related to PB, there is a prejudice - cheap products have low quality - but, evaluation by customers who have used those products shows neutral stand, and there is a study representing that it is the most important to accumulate the belief between the retailers selling PB products and consumers using those for the accurate evaluation and intention on purchasing. Also, by the result from analyzing the characteristics of customers buying PB products, we could assume that higher income and higher education level, more preference on PB products. Especially, according to TNS's research, the primary targets of PB product are 30's who seeks value for money and planned spending habits, and 40's who have teenager children, and are interested in encouraging themselves. This paper used Probit model to analyze the characteristics of consumers. This model helps us to analyze with the variables representing the demographic characteristics of consumers (gender, age, educational level, occupation, income level, living area), and variables related to purchasing behavior (visiting frequency on big retailers, the average amount that they pay for goods in there, and check-up which brand made those goods). The method we used in this study is by man to man interview and survey on-line with the rate of 89% and 11% in Seoul and Gyunggi Province, respectively, for about one month from the beginning of February, 2008. As a result of this, under the assumption that people buy PB products more as long as they go shopping more, it was not meaningful for target groups which we pointed out as frequently visiting customers to be. Although, we have expected women buy more PB products than men do, gender doesn't mean anything for the result. And, it has inferred that married people buy more PB goods than singles do. It was also meaningless with variables related to occupation. Because housewives are often exposed to any kind of supermarket than workers are, we could not get any relatives. Moreover, we couldn't proof that younger generation prefer big retailers more than older people who 50~60's. Education levels doesn't affect on the purchase of PB product as well. Related to living area, the result is statistically not similar as we expected whether living in Seoul or not. It shows there is no relationship with the preference on retail brands and PB products, and it is similar with the study researched by TNS(2008) that customers tend to buy PB product impulsively no matter which brand it is and where they are even though their shopping place is the big market where customers are often using. Variables on which we had meaningful results are income level and living place. That is, customers who have 3,000,000~6,000,000 WON every month on average are more willing to buy PB products than other customers whose income is over 6,000,000 WON, and residents not living in Seoul prefer PB goods than those who are living in Seoul. To explain more about what we got, if there is only one condition about customer's visiting frequency on big retails, we could come up with this result that more exposed to PB products, more purchasing frequency. Consequently, it brings the important insight that large retailers have to prepare something to make customers visit them often to increase selling rate of PB products. To demonstrate the result of analyzing more, what is more efficient variables are demographically including marital status, income level, and residential area to buy items that affect the PB products and could include the frequency of visiting large markets by the purchase habits. Specifically, then, married couples rather than singles, middle-income customers than high-income customers, and local residents not living in Seoul than customers in Seoul are more likely to purchase PB goods. In addition, as long as a customer visits two times more, then the purchasing rate of PB products is to increase over 5.3%. Therefore, it seems that retailers are better to make a shopping place as fun and comfortable places. With overwhelming the idea that PB products are just cheap, one-time purchase goods, it is needed to increase the loyalty on those goods like NB products, try to make PB products as a consideration products set, and occur to sustainable sales. Especially, as suggested by this paper, it seems like it strongly needs to identify the characteristics of customers who prefer PB, to segment those customers, and to select the main target, and to do positioning with well-planned marketing strategies. Then, it is able to give us a meaningful point on marketing strategy by developing the field of PB study, identifying the difference of life style and shopping habits of customers.

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