• Title/Summary/Keyword: time-history analysis method

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Elastic floor response spectra of nonlinear frame structures subjected to forward-directivity pulses of near-fault records

  • Kanee, Ali Reza Taghavee;Kani, Iradj Mahmood Zadeh;Noorzad, Assadollah
    • Earthquakes and Structures
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    • v.5 no.1
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    • pp.49-65
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    • 2013
  • This article presents the statistical characteristics of elastic floor acceleration spectra that represent the peak response demand of non-structural components attached to a nonlinear supporting frame. For this purpose, a set of stiff and flexible general moment resisting frames with periods of 0.3-3.6 sec. are analyzed using forty-nine near-field strong ground motion records. Peak accelerations are derived for each single degree of freedom non-structural component, supported by the above mentioned frames, through a direct-integration time-history analysis. These accelerations are obtained by Floor Acceleration Response Spectrum (FARS) method. They are statistically analyzed in the next step to achieve a better understanding of their height-wise distributions. The factors that affect FARS values are found in the relevant state of the art. Here, they are summarized to evaluate the amplification and/or reduction of FARS values especially when the supporting structures undergo inelastic behavior. The properties of FARS values are studied in three regions: long-period, fundamental-period and short-period. Maximum elastic acceleration response of non-structural component, mounted on inelastic frames, depends on the following factors: inelasticity intensity and modal periods of supporting structure; natural period, damping ratio and location of non-structural component. The FARS values, corresponded to the modal periods of supporting structure, are strongly reduced beyond elastic domain. However, they could be amplified in the transferring period domain between the mentioned modal periods. In the next step, the amplification and/or reduction of FARS values, caused by inelastic behavior of supporting structure, are calculated. A parameter called the response acceleration reduction factor ($R_{acc}$), has been previously used for far-field earthquakes. The feasibility of extending this parameter for near-field motions is focused here, suggested repeatedly in the relevant sources. The nonlinearity of supporting structure is included in ($R_{acc}$) for better estimation of maximum non-structural component absolute acceleration demand, which is ordinarily neglected in the seismic design provisions.

A Study on the Organization of the 『Gongchengzuofazeli (工程做法則例)』 (『공정주법칙례(工程做法則例)』의 구성 체계에 관한 연구)

  • Yang, Hee Sick;Han, Dong Soo
    • Korean Journal of Heritage: History & Science
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    • v.44 no.2
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    • pp.26-45
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    • 2011
  • The Gongchengzuofazeli, which was published in 1734, the 12th year of the Yongzheng (雍正) emperor of the Ching Dynasty, is an authoritative book that discusses the architectural technology and engineering practices at that time. Moreover, buildings constructed during the Ching Dynasty are substantially similar with the book's content. This study is important in that it is done as the first step in conducting a comparative analysis between the Korean and Chinese wood structure mechanism. First, each content of the book is examined according to the editing order. And second, the standard for division between Da-shi (大式) and Xiao-shi (小式) architecture in terms of heavy woodwork method (vol. 1~27) is redefined, from which a new organization is deduced.

The Effect of Voice Therapy for the Treatment of Functional Aphonia: A Preliminary Study (기능적 실성증에 대한 음성치료의 효과 분석: 기초 연구)

  • Kim, No Eul;Kim, Jun Seok;Oh, Jae Hwan;Kim, Dong Young;Woo, Joo Hyun
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.32 no.2
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    • pp.75-80
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    • 2021
  • Background and Objectives Functional aphonia refers to in which by presenting whispering voice and almost producing very high-pitched tensed voices are produced. Voice therapy is the most effective treatment, but there is a lack of consensus for application of voice therapy. The purpose of this study was to examine the vocal characteristics of functional aphonia and the effect of voice therapy applied accordingly. Materials and Method From October 2019 to December 2020, 11 patients with functional aphonia were treated using voice therapy which was processing three stages such as vocal hygiene, trial therapy, and behavioral therapy. Of these, 7 patients who completed the voice evaluation before and after voice therapy was enrolled in this study. By retrospective chart review, clinical information such as sex, age, symptoms, duration, social and medical history, process of voice therapy, subjective and objective findings were analyzed. Voice parameters before and after voice therapy were compared. Results In GRBAS study, grade, rough, and asthenic, and in Consensus Auditory-Perceptual Evaluation of Voice, overall severity, roughness, pitch, and loudness were significantly improved after voice therapy. In Voice handicap index, all of the scores of total and sub-categories were significantly decreased. In objective voice analysis, jitter, cepstral peak prominence, and maximum phonation time were significantly improved. Conclusion The voice therapy was effective for the treatment of functional aphonia by restoring patient's vocalization and improving voice quality, pitch and loudness.

Galloping characteristics of a 1000-kV UHV iced transmission line in the full range of wind attack angles

  • Lou, Wenjuan;Wu, Huihui;Wen, Zuopeng;Liang, Hongchao
    • Wind and Structures
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    • v.34 no.2
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    • pp.173-183
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    • 2022
  • The galloping of iced conductors has long been a severe threat to the safety of overhead transmission lines. Compared with normal transmission lines, the ultra-high-voltage (UHV) transmission lines are more prone to galloping, and the damage caused is more severe. To control the galloping of UHV lines, it is necessary to conduct a comprehensive analysis of galloping characteristics. In this paper, a large-span 1000-kV UHV transmission line in China is taken as a practical example where an 8-bundled conductor with D-shaped icing is adopted. Galerkin method is employed for the time history calculation. For the wind attack angle range of 0°~180°, the galloping amplitudes in vertical, horizontal, and torsional directions are calculated. Furthermore, the vibration frequencies and galloping shapes are analyzed for the most severe conditions. The results show that the wind at 0°~10° attack angles can induce large torsional displacement, and this range of attack angles is also most likely to occur in reality. The galloping with largest amplitudes in all three directions occurs at the attack angle of 170° where the incoming flow is at the non-iced side, due to the strong aerodynamic instability. In addition, with wind speed increasing, galloping modes with higher frequencies appear and make the galloping shape more complex, indicating strong nonlinear behavior. Based on the galloping amplitudes of three directions, the full range of wind attack angles are divided into five galloping regions of different severity levels. The results obtained can promote the understanding of galloping and provide a reference for the anti-galloping design of UHV transmission lines.

Outcome of single-incision laparoscopic cholecystectomy compared to three-incision laparoscopic cholecystectomy for acute cholecystitis

  • Sanggyun Suh;Soyeon Choi;YoungRok Choi;Boram Lee;Jai Young Cho;Yoo-Seok Yoon;Ho-Seong Han
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.27 no.4
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    • pp.372-379
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    • 2023
  • Backgrounds/Aims: While single-incision laparoscopic cholecystectomy (SILC) has advantages in cosmesis and postoperative pain, its utilization has been limited. This study raises the possibility of expanding its indication to acute cholecystitis with the novel method of solo surgery under retrospective analysis. Methods: We compared the outcomes of SILC (n = 58) to those of three-incision laparoscopic cholecystectomy (TILC; n = 117) for acute cholecystitis, being performed from March 2014 to December 2015. Results: Intraoperative results, including the operation time, did not differ significantly, except for drain catheter insertion (p = 0.004). Each group had 1 case of open conversion due to common bile duct injury. There was no significant difference in the length of hospital stay. Either group by itself was not a risk factor for complications, but in preoperative drainage for intraoperative perforation, 3 factors of intraoperative perforation, biliary complication, and history of upper abdominal operation for additional port, only American Society of Anesthesiology (ASA) scores for postoperative complication of Clavien-Dindo grades III and IV were significant risk factors. Conclusions: Our study findings showed comparative outcomes between both groups, providing evidence for the safety and feasibility of SILC for acute cholecystitis.

Collapse failure mechanism of subway station under mainshock-aftershocks in the soft area

  • Zhen-Dong Cui;Wen-Xiang Yan;Su-Yang Wang
    • Geomechanics and Engineering
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    • v.36 no.3
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    • pp.303-316
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    • 2024
  • Seismic records are composed of mainshock and a series of aftershocks which often result in the incremental damage to underground structures and bring great challenges to the rescue of post-disaster and the repair of post-earthquake. In this paper, the repetition method was used to construct the mainshock-aftershocks sequence which was used as the input ground motion for the analysis of dynamic time history. Based on the Daikai station, the two-dimensional finite element model of soil-station was established to explore the failure process of station under different seismic precautionary intensities, and the concept of incremental damage of station was introduced to quantitatively analyze the damage condition of structure under the action of mainshock and two aftershocks. An arc rubber bearing was proposed for the shock absorption. With the arc rubber bearing, the mode of the traditional column end connection was changed from "fixed connection" to "hinged joint", and the ductility of the structure was significantly improved. The results show that the damage condition of the subway station is closely related to the magnitude of the mainshock. When the magnitude of the mainshock is low, the incremental damage to the structure caused by the subsequent aftershocks is little. When the magnitude of the mainshock is high, the subsequent aftershocks will cause serious incremental damage to the structure, and may even lead to the collapse of the station. The arc rubber bearing can reduce the damage to the station. The results can offer a reference for the seismic design of subway stations under the action of mainshock-aftershocks.

Metallurgical Study on the Iron Artifacts Excavated from Sudang-ri Site in Geumsan (금산 수당리유적 출토 철제유물의 금속학적 연구)

  • Park, Hyung-ho;Cho, Nam-chul;Lee, Hun
    • Korean Journal of Heritage: History & Science
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    • v.46 no.3
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    • pp.134-149
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    • 2013
  • The Sudang-ri Site in Geumsan is considered the historic site where Baekje dominated the inland traffic route to Gaya through Geumsan and Jinan in the 5th Century. This study identified the production techniques of iron by conducting an analysis of metallographical microstructure of the artifacts such as an iron sword and an iron sickle that were excavated in Sudang-ri Site, Geumsan, one of the regions ruled by Baekje, and tried to figure out the characteristics and the technical systems of Baekje's ironmaking around the 5th Century by comparing them with other iron artifacts produced around the same time. The analysis showed that various production techniques were applied to the artifacts excavated in Sudang-ri Site, Geumsan. Depending on the production techniques, they can be divided largely into three methods: the simple shape-forging method, the steel manufacture method after forging, and the steel manufacture & heat-treatment method after forging. The iron sickle from the stone chamber tomb No. 1, which was produced only through forging, is mostly composed of soft ferrite at both edges of the blade and at the rear making the use of the weapon impractical. From this fact, it is presumed that they were produced as burial objects or ceremonial accessories for the person buried. The iron axe from the outer stone coffin tomb No. 1 and the iron swords and sickle from the outer stone coffin tomb No. 12, which were produced through the steel manufacture method after forging such as carburizing, did not go through the heat treatment such as quenching, but applied different production processes to each part. Therefore, it is deemed that they were produced as daily tools for cultivation rather than burial objects or ceremonial accessories. The production techniques following the forging process - carburizing and heat treatment - can be found on the iron swords from the outer stone coffin tomb No. 5 and the outer stone coffin tomb No. 12. The sturdy structure of the blade part and the durable structure of the rear processed with heat are deemed to have been produced as weaponry and used by the person buried. Based on the analysis of the iron artifacts excavated from Sudang-ri Site in Geumsan, the characteristics of iron production techniques were investigated by comparing them with the artifacts from Yongwon-ri Site in Cheonan, Bongseon-ri Site in Seocheon, and Bujang-ri Site in Seosan that were made around the same time as the cluster of Baekje tombs examined by the metallographical microstructure analysis of this study. For the iron artifacts analyzed here, the changes in the techniques were investigated using the iron swords common in all of the tombs. In the case of the iron swords, it was identified the heat treatment technique called tempering was applied from the 4th Century.

Analysis of Posting Preferences and Prediction of Update Probability on Blogs (블로그에서 포스팅 성향 분석과 갱신 가능성 예측)

  • Lee, Bum-Suk;Hwang, Byung-Yeon
    • Journal of KIISE:Databases
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    • v.37 no.5
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    • pp.258-266
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    • 2010
  • In this paper, we introduce a novel method to predict next update of blogs. The number of RSS feeds registered on meta-blogs is on the order of several million. Checking for updates is very time consuming and imposes a heavy burden on network resources. Since blog search engine has limited resources, there is a fix number of blogs that it can visit on a day. Nevertheless we need to maximize chances of getting new data, and the proposed method which predicts update probability on blogs could bring better chances for it. Also this work is important to avoid distributed denial-of-service attack for the owners of blogs. Furthermore, for the internet as whole this work is important, too, because our approach could minimize traffic. In this study, we assumed that there is a specific pattern to when a blogger is actively posting, in terms of days of the week and, more specifically, hours of the day. We analyzed 15,119 blogs to determine a blogger's posting preference. This paper proposes a method to predict the update probability based on a blogger's posting history and preferred days of the week. We applied proposed method to 12,115 blogs to check the precision of our predictions. The evaluation shows that the model has a precision of 0.5 for over 93.06% of the blogs examined.

Comparison of Personalized Ad Methods on the Internet and Smart Phone Platforms (인터넷과 스마트폰 환경에서의 개인화된 광고 방법론의 비교 분석)

  • Kim, Jun San;Lee, Jae Kyu
    • Asia pacific journal of information systems
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    • v.22 no.4
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    • pp.125-149
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    • 2012
  • As the smart phone is propagating rapidly, the importance of mobile advertisement has also grown. One of the main characteristics of the Internet and smart phone advertising is that they can deliver personalized advertisements to each customer. The smart phone enables the identification of additional personalized information such as the customer's location and the accessibility to the site at any place any time. As the Internet platform becomes richer, firms that offer the ad services via the wired PC Internet and wireless smart phone are seeking various types of personalized ads. However, their service platform and Information and Communication Technology (ICT) platform should be suitable to the characteristics of personalized ads. This research explores various types of personalized ad methods and evaluates their adequacy encompassing four types of ad service platforms (such as search portal, news portal, e-mall servers, and SNS) and two types of ICT platforms (PC Internet and smart phone). To this end, we classified the personalized ads into seven types: three basic types and four composite types. The basic types of ad methods are identified by considering the current activity that the customer is engaged, the individual profile and log history, and the customer's current location or planning location. Four composite types of ad methods are constructed as the combination of these basic types. For those types of ad methods, we evaluate whether each ad method adequately maps with four types of ad service platforms and two types of ICT platforms. We proposed a metric of evaluation and demonstrated the concept with illustrative numbers. Specifically, we analyze and compare personalized ad methods in three ways. Firstly, the possibility of implementing a personalized ad method on the platform is analyzed to confirm the degree of suitability. Secondly, the value of personalized ad method is analyzed based on the customer accessibility. Lastly, expected effectiveness for each personalized ad method is computed by multiplying the possibility and the value. Through this kind of analysis, the ad service providers as well as advertising companies can evaluate what kinds of personalized ad methods and platforms are possible and suitable to maximize their ad effectiveness on the Internet and smart phone platforms.

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A Study on Article 78 CISG: Interest on Sums in Arrears (CISG 제78조(연체이자(延滯利子) 청구권(請求權))에 대한 고찰(考察))

  • Kim, Tae-Gyeong
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.31
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    • pp.3-25
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    • 2006
  • This study focus on interest for arrears and filling of the gaps left in Article 78 of CISG. In the case of CISG, Article 78 provides for interest any time a payment under a contract is untimely, but does not specify a particular rate of interest or a method to determine such a rate. This issue did not cause any uncertainty under ULIS, the CISG's antecedent, since Article 83 of ULIS provided for 1%p above the official discount rate in the creditor's country. Lacking any CISG general principle as well as any indication by the very same CISG, one can only conclude that the matter must be deferred to the domestic rule of private international law. Actually, resorting to private international law is not only admissible, but expressly required by Article 7(2). In the interpretation and filling of the gaps left in Article 78, there is a considerable difference of opinion especially amongst commentators on whether the gap is a lacuna praeter legem, i.e., one being governed by, but not expressly settled in the CISG, or whether it is an issue falling outside the scope of application of the CISG, i.e. a lacuna intra legem. The protagonists of the former view lay emphasis on the overall objective of the CISG, namely to create a uniform law, whereas the supporters of the latter view refer to the legislative history of Article 78 as the dominant principle in interpreting Article 78. Some authors believe that the issue of determining the rate of interest is not dealt with by CISG and it is, therefore, governed by the applicable domestic law, which is the subsidiary law applicable to the sales contract, since "no special connecting points seem to have developed for the entitlement to interest." In the light of the relevant case law, it seems correct to conclude that the interest rate is not determined by CISG and that courts normally determine it according to their own rules of private international law. While CISG Article 78 expressly does not deal with this issue, PICC Article 7.4.9 and PECL Article 9.508, on the other hand, set forth a precise method for computing interest. Although a method like the one set by PICC may be useful and may encourage uniformity, it still cannot be used under the CISG. The PICC or PECL formula may, however, be a very good starting point in a de jure condendum analysis when a new Article 78 will be drafted, if an interest rate method will ever be embodied in the text of an international convention.

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