• Title/Summary/Keyword: State Space Analysis

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Isogeometric Shape Design Optimization of Power Flow Problems at High Frequencies (고주파수 파워흐름 문제의 아이소-지오메트릭 형상 최적설계)

  • Yoon, Minho;Ha, Seung-Hyun;Cho, Seonho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.3
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    • pp.155-162
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    • 2014
  • Using an isogeometric approach, a continuum-based shape design optimization method is developed for steady state power flow problems at high frequencies. In case the isogeometric method is employed to the shape design optimization, the NURBS basis functions used in CAD geometric modeling are directly utilized to embed the exact geometry into the computational framework so that the design parameterization for shape optimization is much easier than that in the finite element method and consequently provides the enhanced smoothness of design perturbations. Thus, exact geometric models can be used in both the response and the shape sensitivity analyses, where normal vector and curvature are continuous over the whole design space so that enhanced shape sensitivity can be expected. Through numerical examples, the developed isogeometric sensitivity is compared with finite difference one to provide excellent agreement. Also, it turns out that the proposed method works very well in the shape optimization problems.

Time Synchronization Algorithm using the Clock Drift Rate and Reference Signals Between Two Sensor Nodes (클럭 표류율과 기준 신호를 이용한 두 센서 노드간 시간 동기 알고리즘)

  • Kim, Hyoun-Soo;Jeon, Joong-Nam
    • The KIPS Transactions:PartC
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    • v.16C no.1
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    • pp.51-56
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    • 2009
  • Time synchronization algorithm in wireless sensor networks is essential to various applications such as object tracking, data encryption, duplicate detection, and precise TDMA scheduling. This paper describes CDRS that is a time synchronization algorithm using the Clock Drift rate and Reference Signals between two sensor nodes. CDRS is composed of two steps. At first step, the time correction is calculated using offset and the clock drift rate between the two nodes based on the LTS method. Two nodes become a synchronized state and the time variance can be compensated by the clock drift rate. At second step, the synchronization node transmits reference signals periodically. This reference signals are used to calculate the time difference between nodes. When this value exceeds the maximum error tolerance, the first step is performed again for resynchronization. The simulation results on the performance analysis show that the time accuracy of the proposed algorithm is improved, and the energy consumption is reduced 2.5 times compared to the time synchronization algorithm with only LTS, because CDRS reduces the number of message about 50% compared to LTS and reference signals do not use the data space for timestamp.

Crystallographic and Magnetic Properties of Li0.5Fe2.5-χRhχO4 by Using Applied Field Mossbauer Spectrometer (외부자기장 뫼스바우어 분광기를 이용한 Li0.5Fe2.5-χRhχO4의 자기적 성질과 결정학적 구조에 관한 연구)

  • Kang, Kun-Uk;Kim, Chul-Sung
    • Journal of the Korean Magnetics Society
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    • v.14 no.6
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    • pp.219-223
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    • 2004
  • L $i_{0.5}$F $e_{2.5-{\chi}}$R $h_{\chi}$ $O_4$ ($\chi$ = 0.25, 0.50, 0.75, 1.00) has been prepared by solid state reaction. Crystallographic and magnetic properties were investigated by Mossbauer spectroscopy, SQUID magnetometry, and x-ray diffraction. The crystal structure is found to be a cubic spinel structure with space group Fd3m for all the samples. The lattice constant $a_{0}$ increases from 8.3365 $\AA$ to 8.3932 $\AA$ with increasing Rh concentration $\chi$. The migration of Li ion has been confirmed by x-ray patterns and the results of applied field Mossbauer analysis. The temperature dependence of the absorption area of each site was analyzed with the Debye model for the recoil-free fraction. The Debye temperature for the octahedral sites is almost as large as for the tetrahedral sites, thereby suggesting similar inter-atomic binding forces for the octahedral and the tetrahedral sites. The saturated magnetic moment and the Mossbauer spectra taken at 4.2 K under the applied field (6 T) show that the spin structure of L $i_{0.5}$F $e_{2.5-{\chi}}$R $h_{\chi}$ $O_4$ is compatible with the collinear Neel Model.

A Study on the Cyber Weapons Classification System (사이버무기 분류체계에 관한 시론)

  • Lee, Yongseok;Kwon, Hunyeong;Choi, Jeongmin;Lim, Jongin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.4
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    • pp.905-917
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    • 2018
  • The sovereign state has the right to engage in self-defense or war with the approval of the Security Council when it receives an invasion of territory from a foreign country. War is conducted under the principle of the necessity and proportionality of self-defense. In case of cyber attack, proportional countermeasure must be made through attack means and effect analysis, and cyber weapons need to be classified for this purpose. Therefore, this study aims to provide a rational and legitimate response according to the necessity and proportionality of the self - defense right by suggesting definition and classification criteria of cyber weapons. In this study, cyber weapons were defined as "means of collecting, attacking, and protecting information using cyber technology in the cyber space according to military objectives. Based on existing weapon systems and public cyber weapons cases, cyber weapons were classified as (1) cyber weapons for information gathering, (2) cyber weapons for attack, and (3) cyber weapons for protection. We suggest the considerations for applying the proportional response according to this functional classification. In order to guarantee the principle of proportionality to cyber attacks in the future, the classification study based on the cyber weapon effect should be conducted. This study has conducted an exploratory study on the classification of cyber clusters which constitutes one axis of the proportionality principle.

Case Analysis for Application of Bamboo in Floral Designs (화훼장식에서 대나무 활용의 사례 분석)

  • Bang, Sik;Yoon, Pyung Sub;Ryu, Byung Yeol;Kim, Yang Hee
    • FLOWER RESEARCH JOURNAL
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    • v.16 no.1
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    • pp.7-11
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    • 2008
  • In order to investigate the application of bamboo in various ways in floral designs, we analyzed 108 bamboo items from the monthly magazine 'Fleur' and from the International Flower Contest held from 2001 to 2006. We analyzed the frequency of usage of bamboos by the used parts, kind of design, type of design, and arrangement method in the design work. In terms of the used parts of the bamboo, stems took 90% of the whole work. Among the 77 designs that used stems, excluding the 20 work items presented in the International Flower Contest which has been held in April, number of the bamboo work items peaked at the beginning of the year in January and February, and during summer (July and August). Upon analyzing the type of stems that were used in the 97 works, 63% of the works used bamboo in natural state, but not processed. 48% of the works used the vertical-parallel method among the arrangement methods. Other categorized works were rounded works that were not included in the vertical, horizontal or diagonal mathod. More than 50% of the works, including the table decoration, used space decoration. Among the types of work design that used bamboo as material, 64% were decorative type, 30% graphic type, and 4% formal-linear type.

Improvement of Multi-Dimensional Urban Planning System for Urban Regeneration (도시재생 측면에서 입체도시계획의 기능과 제도 개선 방안)

  • Lee, Bum-Hyun;Nam, Seong-Woo;Kim, Young-Hyun
    • The Journal of the Korea Contents Association
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    • v.19 no.2
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    • pp.516-524
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    • 2019
  • The purpose of this study is to analyze the cases related to the multi-dimensional urban planning and its related systems that can contribute to the urban regeneration as the policies and projects for stereoscopic city increase. Through the case analysis, urban regeneration function and role of multi-dimensional urban planning are identified as connection of places, activation of local economy, expansion of infrastructure and supply of housing. In the institutional sector, private participation is hindered due to the ban on the establishment of the right to hold state property. In addition, it is difficult to utilize the three-dimensional urban space without land securing at a certain rate based on uniform installation standards of the two-dimensional land use plan, and the problem of insufficient interconnection between law and institution is derived. In conclusion, it should actively support and promote the promotion of the three-dimensional facility with the aim of diversifying the regional infrastructure structure and strengthening the urban function. In addition, development of stereoscopic and compound development should be promoted for old urban areas, and parking lots, underground shopping malls, parking lots, etc. should be installed using the subspaces of parks, schools, roads and traditional markets of old residential areas. Finally, cooperation between the central government, the municipalities and the private sector is necessary for the realization of these urban regeneration projects.

Neutrophil to Lymphocyte Ratio and Serum Biomarkers : A Potential Tool for Prediction of Clinically Relevant Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage

  • Osman Kula;Burak Gunay;Merve Yaren Kayabas;Yener Akturk;Ezgi Kula;Banu Tutunculer;Necdet Sut;Serdar Solak
    • Journal of Korean Neurosurgical Society
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    • v.66 no.6
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    • pp.681-689
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    • 2023
  • Objective : Subarachnoid hemorrhage (SAH) is a condition characterized by bleeding in the subarachnoid space, often resulting from the rupture of a cerebral aneurysm. Delayed cerebral ischemia caused by vasospasm is a significant cause of mortality and morbidity in SAH patients, and inflammatory markers such as systemic inflammatory response index (SIRI), systemic inflammatory index (SII), neutrophil-to-lymphocyte ratio (NLR), and derived NLR (dNLR) have shown potential in predicting clinical vasospasm and outcomes in SAH patients. This article aims to investigate the relationship between inflammatory markers and cerebral vasospasm after aneurysmatic SAH (aSAH) and evaluate the predictive value of various indices, including SIRI, SII, NLR, and dNLR, in predicting clinical vasospasm. Methods : A retrospective analysis was performed on a cohort of 96 patients who met the inclusion criteria out of a total of 139 patients admitted Trakya University Hospital with a confirmed diagnosis of aSAH between January 2013 and December 2021. Diagnostic procedures, neurological examinations, and laboratory tests were performed to assess the patients' condition. The Student's t-test compared age variables, while the chi-square test compared categorical variables between the non-vasospasm (NVS) and vasospasm (VS) groups. Receiver operating characteristic (ROC) curve analyses were used to evaluate the diagnostic accuracy of laboratory parameters, calculating the area under the ROC curve, cut-off values, sensitivity, and specificity. A significance level of p<0.05 was considered statistically significant. Results : The study included 96 patients divided into two groups : NVS and VS. Various laboratory parameters, such as NLR, SII, and dNLR, were measured daily for 15 days, and statistically significant differences were found in NLR on 7 days, with specific cut-off values identified for each day. SII showed a significant difference on day 9, while dNLR had significant differences on days 2, 4, and 9. Graphs depicting the values of these markers for each day are provided. Conclusion : Neuroinflammatory biomarkers, when used alongside radiology and scoring scales, can aid in predicting prognosis, determining severity and treatment decisions for aSAH, and further studies with larger patient groups are needed to gain more insights.

Review on Rock-Mechanical Models and Numerical Analyses for the Evaluation on Mechanical Stability of Rockmass as a Natural Barriar (천연방벽 장기 안정성 평가를 위한 암반역학적 모델 고찰 및 수치해석 검토)

  • Myung Kyu Song;Tae Young Ko;Sean S. W., Lee;Kunchai Lee;Byungchan Kim;Jaehoon Jung;Yongjin Shin
    • Tunnel and Underground Space
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    • v.33 no.6
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    • pp.445-471
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    • 2023
  • Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.

Consumer Responses to Retailer's Location-based Mobile Shopping Service : Focusing on PAD Emotional State Model and Information Relevance (유통업체의 위치기반 모바일 쇼핑서비스 제공에 대한 소비자 반응 : PAD 감정모델과 정보의 상황관련성을 중심으로)

  • Lee, Hyun-Hwa;Moon, Hee-Kang
    • Journal of Distribution Research
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    • v.17 no.2
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    • pp.63-92
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    • 2012
  • This study investigated consumer intention to use a location-based mobile shopping service (LBMSS) that integrates cognitive and affective responses. Information relevancy was integrated into pleasure-arousal-dominance (PAD) emotional state model in the present study as a conceptual framework. The results of an online survey of 335 mobile phone users in the U.S. indicated the positive effects of arousal and information relevancy on pleasure. In addition, there was a significant relationship between pleasure and intention to use a LBMSS. However, the relationship between dominance and pleasure was not statistically significant. The results of the present study provides insight to retailers and marketers as to what factors they need to consider to implement location-based mobile shopping services to improve their business performance. Extended Abstract : Location aware technology has expanded the marketer's reach by reducing space and time between a consumer's receipt of advertising and purchase, offering real-time information and coupons to consumers in purchasing situations (Dickenger and Kleijnen, 2008; Malhotra and Malhotra, 2009). LBMSS increases the relevancy of SMS marketing by linking advertisements to a user's location (Bamba and Barnes, 2007; Malhotra and Malhotra, 2009). This study investigated consumer intention to use a location-based mobile shopping service (LBMSS) that integrates cognitive and affective response. The purpose of the study was to examine the relationship among information relevancy and affective variables and their effects on intention to use LBMSS. Thus, information relevancy was integrated into pleasure-arousal-dominance (PAD) model and generated the following hypotheses. Hypothesis 1. There will be a positive influence of arousal concerning LBMSS on pleasure in regard to LBMSS. Hypothesis 2. There will be a positive influence of dominance in LBMSS on pleasure in regard to LBMSS. Hypothesis 3. There will be a positive influence of information relevancy on pleasure in regard to LBMSS. Hypothesis 4. There will be a positive influence of pleasure about LBMSS on intention to use LBMSS. E-mail invitations were sent out to a randomly selected sample of three thousand consumers who are older than 18 years old and mobile phone owners, acquired from an independent marketing research company. An online survey technique was employed utilizing Dillman's (2000) online survey method and follow-ups. A total of 335 valid responses were used for the data analysis in the present study. Before the respondents answer any of the questions, they were told to read a document describing LBMSS. The document included definitions and examples of LBMSS provided by various service providers. After that, they were exposed to a scenario describing the participant as taking a saturday shopping trip to a mall and then receiving a short message from the mall. The short message included new product information and coupons for same day use at participating stores. They then completed a questionnaire containing various questions. To assess arousal, dominance, and pleasure, we adapted and modified scales used in the previous studies in the context of location-based mobile shopping service, each of the five items from Mehrabian and Russell (1974). A total of 15 items were measured on a seven-point bipolar scale. To measure information relevancy, four items were borrowed from Mason et al. (1995). Intention to use LBMSS was captured using two items developed by Blackwell, and Miniard (1995) and one items developed by the authors. Data analyses were conducted using SPSS 19.0 and LISREL 8.72. A total of usable 335 data were obtained after deleting the incomplete responses, which results in a response rate of 11.20%. A little over half of the respondents were male (53.9%) and approximately 60% of respondents were married (57.4%). The mean age of the sample was 29.44 years with a range from 19 to 60 years. In terms of the ethnicity there were European Americans (54.5%), Hispanic American (5.3%), African-American (3.6%), and Asian American (2.9%), respectively. The respondents were highly educated; close to 62.5% of participants in the study reported holding a college degree or its equivalent and 14.5% of the participants had graduate degree. The sample represents all income categories: less than $24,999 (10.8%), $25,000-$49,999 (28.34%), $50,000-$74,999 (13.8%), and $75,000 or more (10.23%). The respondents of the study indicated that they were employed in many occupations. Responses came from all 42 states in the U.S. To identify the dimensions of research constructs, Exploratory Factor Analysis (EFA) using a varimax rotation was conducted. As indicated in table 1, these dimensions: arousal, dominance, relevancy, pleasure, and intention to use, suggested by the EFA, explained 82.29% of the total variance with factor loadings ranged from .74 to .89. As a next step, CFA was conducted to validate the dimensions that were identified from the exploratory factor analysis and to further refine the scale. Table 1 exhibits the results of measurement model analysis and revealed a chi-square of 202.13 with degree-of-freedom of 89 (p =.002), GFI of .93, AGFI = .89, CFI of .99, NFI of .98, which indicates of the evidence of a good model fit to the data (Bagozzi and Yi, 1998; Hair et al., 1998). As table 1 shows, reliability was estimated with Cronbach's alpha and composite reliability (CR) for all multi-item scales. All the values met evidence of satisfactory reliability in multi-item measure for alpha (>.91) and CR (>.80). In addition, we tested the convergent validity of the measure using average variance extracted (AVE) by following recommendations from Fornell and Larcker (1981). The AVE values for the model constructs ranged from .74 through .85, which are higher than the threshold suggested by Fornell and Larcker (1981). To examine discriminant validity of the measure, we again followed the recommendations from Fornell and Larcker (1981). The shared variances between constructs were smaller than the AVE of the research constructs and confirm discriminant validity of the measure. The causal model testing was conducted using LISREL 8.72 with a maximum-likelihood estimation method. Table 2 shows the results of the hypotheses testing. The results for the conceptual model revealed good overall fit for the proposed model. Chi-square was 342.00 (df = 92, p =.000), NFI was .97, NNFI was .97, GFI was .89, AGFI was .83, and RMSEA was .08. All paths in the proposed model received significant statistical support except H2. The paths from arousal to pleasure (H1: ${\ss}$=.70; t = 11.44), from information relevancy to intention to use (H3 ${\ss}$ =.12; t = 2.36), from information relevancy to pleasure (H4 ${\ss}$ =.15; t = 2.86), and pleasure to intention to use (H5: ${\ss}$=.54; t = 9.05) were significant. However, the path from dominance to pleasure was not supported. This study investigated consumer intention to use a location-based mobile shopping service (LBMSS) that integrates cognitive and affective responses. Information relevancy was integrated into pleasure-arousal-dominance (PAD) emotional state model as a conceptual framework. The results of the present study support previous studies indicating that emotional responses as well as cognitive responses have a strong impact on accepting new technology. The findings of this study suggest potential marketing strategies to mobile service developers and retailers who are considering the implementation of LBMSS. It would be rewarding to develop location-based mobile services that integrate information relevancy and which cause positive emotional responses.

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Analysis on the Movement Found in an Animation - Focusing on Laban's Effort - (애니메이션 <몬스터 대학교>의 움직임 분석 -라반의 에포트를 중심으로)

  • Sung, Rea
    • Cartoon and Animation Studies
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    • s.40
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    • pp.33-53
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    • 2015
  • The movement of characters is one of the crucial elements to deliver their emotion flowing inside. Though it is the same movement, it may appear or be expressed differently according to the character's personality or emotion or the particular situation. The purpose of this study is to analyze not only the movement found superficially in an animation but also a character's internal emotion and attitude with Laban's movement analysis system, particularly effort, one of its analysis categories, and examine how effectively Laban's movement analysis often employed at the circles of dance can analyze movement in an animation. is about a monster that constantly makes efforts to realize its dream to be a scarer. Functional movement forms the most part, but expressive movement to show how a character thinks or feels also appears harmoniously. Characters' externally shown movement can express their internal emotion properly sometimes, but they also often move expressing their feelings in moderation. Therefore, this study analyzes the movement of characters found in the four scenes of with LMA's effort. According to the findings, at the scene where Michael enters the door leading to the human world following the scarer, the emotional state of Michael envious of the scarer is expressed with the Vision Drive giving the strong feel of dreaming. At the scene of the second game to choose the best scare team, it shows us the Spell Drive with its careful and light movement having clear intention to survive at the game. At the scene where there is a party held for the teams that have survived, it shows the Passion Drive of being eagerly expressing happy and delightful feelings without considering what is around. At the scene where Michael and Sullivan are pursued by people, the Action Drive was used to express movement that was heavy and strong and was getting faster gradually by focusing the feelings of the characters in haste into one place.