• Title/Summary/Keyword: re-estimation

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Significance of seabed interaction on fatigue assessment of steel catenary risers in the touchdown zone

  • Elosta, Hany;Huang, Shan;Incecik, Atilla
    • Structural Engineering and Mechanics
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    • v.57 no.3
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    • pp.403-423
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    • 2016
  • The challenges involved with fatigue damage assessment of steel catenary riser (SCR) in the touchdown zone (TDZ) are primarily due to the non-linear behaviour of the SCR-seabed interaction, considerable uncertainty in SCR-seabed interaction modelling and geotechnical parameters. The issue of fatigue damage induced by the cyclic movements of the SCR with the seabed has acquired prominence with the touch down point (TDP) interaction in the TDZ. Therefore, the SCR-seabed response is critical for reliable estimation of fatigue life in the TDZ. Various design approaches pertaining to the lateral pipe-soil resistance model are discussed. These techniques have been applied in the finite element model that can be used to analyse the lateral SCR-seabed interaction under hydrodynamic loading. This study investigates the sensitivity of fatigue performance to geotechnical parameters through a parametric study. In this study, global analyses are performed to assess the influence of vertical linear seabed springs, the lateral seabed model and the non-linear seabed model, including trench evolution into seabed, seabed normalised stiffness, re-penetration offset parameter and soil suction resistance ratio, on the fatigue life of SCRs in the TDZ.

The Estimation of The Productivities of Institutions under Ministry of Oceans and Fisheries (해양수산부 산하기관의 생산성 추정에 관한 연구)

  • KIM, Tae-Hyun;KIM, Jong-Cheon;PARK, Cheol-Hyung
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.1
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    • pp.186-197
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    • 2016
  • This study applied the parametric bootstrapping method to analyze whether there was a change in the production efficiency of institutions under Ministry of Oceans and Fisheries. This study used input and output oriented productivity simultaneously. In particular, the productivity was estimated through 95% confidence interval derived by 2000 times re-sampling process. The results of the study showed us a reduction in overall total factor productivity by 24% between 2009 and 2013, and 7% of decreases in productivity annually. A recent conditions of an external economic shocks brought a 28% downward shift of production function. In this study, public institutions were divided into three types, which were public, quasi-government, and other public institutions. There were approximately 13%, 1%, and 5% decreases in total factor productivity per each. In analyzing the productivity each of 14 institutions, approximately DMU4 and DMU6 had 4%, and 5% increases in productivity per each. While DMU14 showed us no changes in productivity, all of the other 10 DMUs were estimated the decreases in productivities.

Determination of Proper Probability Distribution for Groundwater Monitoring Stations in Jeju Island (제주도 지하수위 관측지점별 적정 확률분포형의 결정)

  • Chung, Il-Moon;Nam, Woosung;Kim, Min Gyu;Choi, Gian;Kim, Gee-Pyo;Park, Yun-Seok
    • Journal of Soil and Groundwater Environment
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    • v.23 no.1
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    • pp.41-53
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    • 2018
  • Comprehensive statistical analysis for the 127 groundwater monitoring stations in Jeju Island during 2005~2015 was carried out for the re-establishment of management groundwater level. Three probability distribution functions such as normal distibution, GEV (General Extreme Value) distribution, and Gumbel distribution were applied and the maximum likelihood method was used for parameter estimation of each distribution. AIC (Akaike information criterion) was calculated based on the estimated parameters to determine the proper probability distribution for all 127 stations. The results showed that normal distribution and Gumble distribution were found in 11 stations. Whereas GEV distribution were found in 105 stations, which covered most of groundwater monitoring stations. Therefore, confidence levels should be established in accord with the proper probability distribution when groundwater level management is determined.

Determinants of Micro-, Small- and Medium-Sized Enterprise Loans by Commercial Banks in Indonesia

  • YUDARUDDIN, Rizky
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.19-30
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    • 2020
  • This paper investigates, in a single equation framework, the effect of bank-specific and macroeconomic determinants on micro-, small- and medium-sized loans by commercial banks in Indonesia. This study uses a sample of 790 observations from 79 commercial banks in Indonesia over the years 2006-2015. This study uses two estimation methods for our panel regressions: static and dynamic generalized method of moments (GMM) panel estimator. In static relationships, the literature usually uses the least square methods on fixed effects (FE) or random effects (RE). I found evidence that all banks, bank profitability and size are positively and significantly related to micro-, small- and medium-sized loans, while the coefficients of liquidity are significantly positive in all specifications, except government banks which is significantly negative. The relationship between risk and credit growth is negative for non-government banks. All estimated equations show that the effect of the capital variable on lending banks to MSMEs is not important in government banks and non-government banks. Finally, macroeconomic variables, such as inflation and gross domestic product, clearly affect the lending of the banking sector particularly non-state banks. The findings have several policy implications to Indonesia government, regulatory authority and bank managers in order to improve bank profitability through bank lending.

An Efficient Mot ion Vector Re-estimation Algorithm for Frame Rate Conversion in MPEG Video Transcoding (MPEG 비디오 트랜스코딩에서 프레임율 변환을 위한 효율적인 움직임 벡터 재추정 기법)

  • Choi Youngtai;Yang Siyoung;Jeong Jechang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2004.11a
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    • pp.233-236
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    • 2004
  • 다양한 처리능력을 가진 단말기들은 복잡한 네트워크, 환경의 호환성을 제공하기 위해서, 전송 네트워크 채널이 허용하는 범위내로 부호화 된 비디오의 비트 율을 적응적으로 맞춰 주어야 한다 트랜스코더는 특정 비트율로 부호화되어 있는 비디오를 원하는 비트율의 다시 변환하기 위해서 복호화 만 후 다시 부호와의 과정을 거쳐야 하기 때문에 이에 따른 계산량의 증가와 더불어 전송시간에 문제가 발생한다. 이를 해결하기 위한 한 가지 방법으로 제안된 것이 프레임 건너뜀 기법 즉 시간적 해상도 변환 트랜스코딩이다. 비디오를 부호화하는 과정에서 계산량을 가장 많이 차지하는 움직임 추정과정의 계산량을 줄임으로써 트랜스코딩을 수행하는데 소모되는 시간과 노력을 크게 줄이고, 건너뛰지 않고 남아있는 프레임에 더 많은 비트를 할당하여 요구되는 화질을 유지할 수 있다. 본 논문에서는 움직임 벡터의 방향성을 고려한 움직임 벡터 재추정 기법과 정제 기법을 제안한다 제안된 기법인 E-FDVS(Efficient-Forward Dominant Vector Selection)는 움직임 벡터의 방향성을 고려하여 매크로블록과 움직임 벡터의 차이를 이용하여 움직임 벡터를 재추정한다. 그리고 제안한 기법인 DOS(Direction Oriented Search)를 사용하여 재추정 된 움직임 벡터의 방향으로 강한 움직임 벡터 정제를 함으로써 기존의 기법에 비해 우수한 화질을 제공한다.

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A Study for Professionalizlng of Multi-family Housing Manager (공동주택관리사의 전문직화를 위한 탐색적 연구)

  • 은난순;유병선;홍형옥
    • Journal of Families and Better Life
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    • v.21 no.3
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    • pp.109-121
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    • 2003
  • The purpose of this study was to investigate the difficulty of doing job among housing manager. It might be Provide the basic opinion which could be used for professionalizing of housing manager. The survey had been made 156 housing manager in managerial situation of multi-family housing for sale(so called condominium). The analytical methods adopted in this study were frequency, percentage, 1-test, one-way ANOVA, post-hoc estimation(Scheffe test), correlation by the SPSS 10.1 for Windows program. The major findings of this study were as follows. First, it was revealed that many housing manager thought about Residents' Committee In the negative. Because housing manager considered that Residents' Committee interfered in housing manager's business, on the other hand they set a low value on Residents' Committee disposition and its knowledge about housing management. Second, it was founded that a lot of housing manager felt uneasy about his employment for the reason mentioned. Actually Residents' Committee exercised its influence over hiring as well as dismissing housing manager in any management alternatives. Third, it was necessary that synthetic plan might be prepared for housing manager to educate, to re-educate, to furnish information etc. about related in housing management for the specialization of housing management.

A Structure of Personalized e-Learning System Using On/Off-line Mixed Estimations Based on Multiple-Choice Items

  • Oh, Yong-Sun
    • International Journal of Contents
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    • v.5 no.1
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    • pp.51-55
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    • 2009
  • In this paper, we present a structure of personalized e-Learning system to study for a test formalized by uniform multiple-choice using on/off line mixed estimations as is the case of Driver :s License Test in Korea. Using the system a candidate can study toward the license through the Internet (and/or mobile instruments) within the personalized concept based on IRT(item response theory). The system accurately estimates user's ability parameter and dynamically offers optimal evaluation problems and learning contents according to the estimated ability so that the user can take possession of the license in shorter time. In order to establish the personalized e-Learning concepts, we build up 3 databases and 2 agents in this system. Content DB maintains learning contents for studying toward the license as the shape of objects separated by concept-unit. Item-bank DB manages items with their parameters such as difficulties, discriminations, and guessing factors, which are firmly related to the learning contents in Content DB through the concept of object parameters. User profile DB maintains users' status information, item responses, and ability parameters. With these DB formations, Interface agent processes user ID, password, status information, and various queries generated by learners. In addition, it hooks up user's item response with Selection & Feedback agent. On the other hand, Selection & Feedback agent offers problems and content objects according to the corresponding user's ability parameter, and re-estimates the ability parameter to activate dynamic personalized learning situation and so forth.

Passive parasitic UWB antenna capable of switched beam-forming in the WLAN frequency band using an optimal reactance load algorithm

  • Lee, Jung-Nam;Lee, Yong-Ho;Lee, Kwang-Chun;Kim, Tae Joong
    • ETRI Journal
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    • v.41 no.6
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    • pp.715-730
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    • 2019
  • We propose a switched beam-forming antenna that satisfies not only ultra-wideband characteristics but also beam-forming in the WLAN frequency band using an ultra-wideband antenna and passive parasitic elements applying a broadband optimal reactance load algorithm. We design a power and phase estimation function and an error correction function by re-analyzing and normalizing all the components of the parasitic array using control system engineering. The proposed antenna is compared with an antenna with a pin diode and reactance load value, respectively. The pin diode is located between the passive parasitic elements and ground plane. An antenna beam can be formed in eight directions according to the pin diode ON (reflector)/OFF (director) state. The antenna with a reactance load value achieves a better VSWR and gain than the antenna with a pin diode. We confirm that a beam is formed in eight directions owing to the RF switch operation, and the measured peak gain is 7 dBi at 2.45 GHz and 10 dBi at 5.8 GHz.

Design and Implementation of the Efficient Web-based Individual RC2 system with Learning Problem Structure (학습문제 구조화를 통한 효율적인 웹기반 개별화 학습시스템 RC2의 설계 및 구현)

  • Song, Min-A;Song, Eun-Ha;Jung, Kwon-Ho;Jeong, Young-Sik
    • The Journal of Korean Association of Computer Education
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    • v.3 no.1
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    • pp.51-63
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    • 2000
  • All learners can selection of their work through hypermedia technology in the area provided by usual WBI. Also, it provides learner with individual teaching-learning environment and estimation. RC2 System has the fundamental client/server model, and provides the learning, evaluation algorithms based on the LCPG(Learning Contents Problem Graph) model, the dynamic re-learning mechanism in according to the property of individual. Moreover, it support learning editor to provide interface, which is convenient for teacher, Courseware writer, on the Web

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HMM-based Music Identification System for Copyright Protection (저작권 보호를 위한 HMM기반의 음악 식별 시스템)

  • Kim, Hee-Dong;Kim, Do-Hyun;Kim, Ji-Hwan
    • Phonetics and Speech Sciences
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    • v.1 no.1
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    • pp.63-67
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    • 2009
  • In this paper, in order to protect music copyrights, we propose a music identification system which is scalable to the number of pieces of registered music and robust to signal-level variations of registered music. For its implementation, we define the new concepts of 'music word' and 'music phoneme' as recognition units to construct 'music acoustic models'. Then, with these concepts, we apply the HMM-based framework used in continuous speech recognition to identify the music. Each music file is transformed to a sequence of 39-dimensional vectors. This sequence of vectors is represented as ordered states with Gaussian mixtures. These ordered states are trained using Baum-Welch re-estimation method. Music files with a suspicious copyright are also transformed to a sequence of vectors. Then, the most probable music file is identified using Viterbi algorithm through the music identification network. We implemented a music identification system for 1,000 MP3 music files and tested this system with variations in terms of MP3 bit rate and music speed rate. Our proposed music identification system demonstrates robust performance to signal variations. In addition, scalability of this system is independent of the number of registered music files, since our system is based on HMM method.

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