• Title/Summary/Keyword: Valid and Invalid

Search Result 67, Processing Time 0.031 seconds

Prior Thinking and Posterior Thinking Formation of Children and Adolescents In Sinking Objects (물체의 수중낙하에 대한 아동 및 청소년의 사전생각과 사후생각 형성)

  • 김헤라;유안진
    • Journal of the Korean Home Economics Association
    • /
    • v.40 no.5
    • /
    • pp.39-51
    • /
    • 2002
  • The purpose of this study is to investigate prior thinking and posterior thinking formation of children and adolescents in sinking objects. The subjects consisted of twenty eight, 9- and 11-year old children and fourteen, 13-year old adolescents selected from one elementary school and two middle schools. The transcripts were analyzed to classify children and adolescents'prior thinking and posterior thinking frequency, reasoning response(evidence based response, idea based response) and reasoning method(valid method, invalid method). The data were analyzed by frequency, percentile, mean and standard deviation,1 test, ANOVA. Major findings were as followings: 1. Children and adolescents have already had prior thinking in sinking objects. 2. Children and adolescents applies their prior thinking to posterior thinking formation process. 3. There were significant differences in children and adolescent'posterior thinking formation process, especially choices in objects and reasoning methods depending on age. 4. There were significant differences in children and adolescents'reasoning response depending on presented evidences types.5. Through the experimentation, children and adolescents'prior thinking was different from their posterior thinking. There were significant differences in differences between the prior thinking and posterior thinking depending on age.

A Study on the Significance of Spatial Interaction Model from the Urban Competitive Point of View (입지 경쟁력과 공간상호작용 모형의 유의성 검정)

  • Kim, Dong-Yoon
    • Journal of The Korean Digital Architecture Interior Association
    • /
    • v.12 no.1
    • /
    • pp.71-79
    • /
    • 2012
  • This study aims at finding relationships between the competitiveness of cities and the size or distance of them, based on some premises; (1) the competitiveness can be measured on the interval-ratio level, that is, factor scores, (2) a hypothesis that the spatial interaction model is valid for the relationships can be generally accepted. Based on the general recognition a research hypothesis that the more is the population or the nearer is the distance from a central city the higher is the competitiveness score is constructed. According to the premises 5-factor scores and composite score are calculated by means of regression method, and the scores are regressed on cities' populations and distances from Seoul city. Using bootstrapping method for the tests of significance is effective due to small sample of 21 cities. Results of the analyses show that most aspects of the hypothesis should be rejected or adjusted. Scores on Health-welfare factor, public service factor, and commercial vitality factor have no relation to the cities' sizes or distances. But the results also find the facts that the strong (negative) relationships exist between (1) educational base factor score and population, (2) density factor score and distance. Although this study improves systematic and analytic understanding of spatial interaction patterns, the understanding should be invalid for the general context because it has used the data on 21 cities in the capital region at the time of 2009.

Frequency analysis of nonidentically distributed large-scale hydrometeorological extremes for South Korea

  • Lee, Taesam;Jeong, Changsam;Park, Taewoong
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2015.05a
    • /
    • pp.537-537
    • /
    • 2015
  • In recent decades, the independence and identical distribution (iid) assumption for extreme events has been shown to be invalid in many cases because long-term climate variability resulting from phenomena such as the Pacific decadal variability and El Nino-Southern Oscillation may induce varying meteorological systems such as persistent wet years and dry years. Therefore, in the current study we propose a new parameter estimation method for probability distribution models to more accurately predict the magnitude of future extreme events when the iid assumption of probability distributions for large-scale climate variability is not adequate. The proposed parameter estimation is based on a metaheuristic approach and is derived from the objective function of the rth power probability-weighted sum of observations in increasing order. The combination of two distributions, gamma and generalized extreme value (GEV), was fitted to the GEV distribution in a simulation study. In addition, a case study examining the annual hourly maximum precipitation of all stations in South Korea was performed to evaluate the performance of the proposed approach. The results of the simulation study and case study indicate that the proposed metaheuristic parameter estimation method is an effective alternative for accurately selecting the rth power when the iid assumption of extreme hydrometeorological events is not valid for large-scale climate variability. The maximum likelihood estimate is more accurate with a low mixing probability, and the probability-weighted moment method is a moderately effective option.

  • PDF

A Study on the Realtime Cert-Validation of Certification based on DARC (DARC 기반에서의 실시간 인증서 유효성 검증에 관한 연구)

  • Jang, Heung-Jong;Lee, Seong-Eun;Lee, Jeong-Hyeon
    • The KIPS Transactions:PartC
    • /
    • v.8C no.5
    • /
    • pp.517-524
    • /
    • 2001
  • There are cases that revoke the certification because of disclosure of private key, deprivation of qualification and the expiration of a term of validity based on PKI. So, a user have to confirm the public key whether valid or invalid in the certification. There are many method such as CRL, Delta-CRL, OCSP for the cert-validation of certification. But these method many problems which are overload traffic on network and the CRL server because of processing for cert-validation of certification. In this paper we proposed the realtime cert-validation of certification method which solved problems that are data integrity by different time between transmission and receiving for CRL, and overload traffic on network and the CRL server based on DARC.

  • PDF

A New Approach to Robustly Exchange Models in Heterogeneous CAD/CAE Environment and its Application

  • Kim, In-Il;Jang, Young-Heuy;Suh, Heung-Won;Han, Seong-Hwan
    • Journal of Ship and Ocean Technology
    • /
    • v.10 no.2
    • /
    • pp.11-23
    • /
    • 2006
  • The model exchange from CAD system to CAE system in valid and effective manner is the major issue of automatic analysis modelling of ship structure. However, model exchange approaches based on the neutral CAD file have resulted in invalid model exchange that could not properly reflect the characteristics of CAD model and CAE model of ship structure. This paper presents the new approach of n-to-n mapping to exchange ship structure model in heterogeneous CAD/CAE environments. In this study, the common model called 'unified ship model for analysis' to directly extract proper information from different CAD systems for ship structural analysis is proposed. Moreover, a command language based model interfacing technique to construct an idealized model for analysis job is also proposed. The proposed approach has been actually implemented in DSME CAD/CAE environment of ship structure such as TRIBON system, PATRAN system and FLUENT system. The applicability and effectiveness of the proposed approach was verified by applying it to the real analysis project for fore-body of ship and block lifting. This application results show that the proposed approach can be effectively used for heterogeneous CAD/CAE environment.

Effects of Auricular Acupressure on Menstrual Pain, Dysmenorrhea, and Academic Stress in Women College Students (이압요법이 여대생의 월경통, 월경곤란증 및 학업 스트레스에 미치는 효과)

  • Ro, Seung-Ok;Lee, Hea-Young;Lee, Jaeon;Kim, Miyoung
    • Korean Journal of Adult Nursing
    • /
    • v.25 no.3
    • /
    • pp.356-364
    • /
    • 2013
  • Purpose: The purpose of this study was to determine the effects of auricular acupressure on menstrual pain, dysmenorrhea and academic stress among college students. Methods: A non-equivalent pretest-posttest design was used. Participants were 57 female students recruited from one college. The treatment group (n=30) received an auricular acupressure on a valid zone and the control group (n=27) received an auricular acupressure on an invalid zone (placebo). The independent t-test and ${\chi}^2$-test were used to examine group differences by using SPSS/Win18.0. Results: Subjects in the treatment group reported much less menstrual pain of premenstrual day (p=.001), 1st day (p<.001), 2nd day (p=.003), and dysmenorrhea (p=.003). Of significance, participants in the treatment group reported much less academic stress (p=.049) following auricular acupressure. Conclusion: The findings support that auricular acupressure is effective in controlling menstrual pain and academic stress related to menstruation. As the method is simple it would be useful for women students to be taught and encouraged to utilize this method to mitigate the symptoms related to menstruation through self care.

A Study on the Validity of the Deviation Clause of B/L in the Contract for the Carriage of Goods by Sea (해상운송계약(海上運送契約)에서 선화증권(船貨證券) 이로조항(離路條項)의 유효성(有效性)에 관한 고찰(考察))

  • Kang, Byeong-Chang;Jo, Jong-Ju
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
    • /
    • v.18
    • /
    • pp.137-157
    • /
    • 2002
  • The clauses of bill of lading(B/L) consist of the terms of contract for the carriage of goods by sea because of clauses of B/L by the mutual agreement of contracting parties. There are some exempted cause of deviation clause in B/L for specific reasons. Then deviation clauses are influenced by Rules of international carriage of goods by sea, because the international rules become the governing law of contract for the carriage of goods by sea. The problem of deviation clauses in B/L is stipulated as follows. "It shall be prerequisite to the Merchant' claim for damages on account of deviation that the merchant's insurance shall first have been cancelled on account of alleged deviation. No deviation shall oust the right to limit liability or damages, and the Carrier shall always be entitled to the full benefit of all privileges, rights and immunities contained in this Bill of Lading and incorporated tariffs." This stipulation should be adjusted according to the confirmed cases, otherwise it will be invalid according to the Hague Rules and Hamburg rules. The sphere of a reasonable deviation in the deviation clause should be interpreted in the connection with the designed voyage and the commercial object of contract for the carriage of goods by sea and the deviation become valid unless the policy, the general object of international rules or the true intention of contracting parties has violated.

  • PDF

A Study on the Statistical Model Validation using Response-adaptive Experimental Design (반응적응 시험설계법을 이용하는 통계적 해석모델 검증 기법 연구)

  • Jung, Byung Chang;Huh, Young-Chul;Moon, Seok-Jun;Kim, Young Joong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2014.10a
    • /
    • pp.347-349
    • /
    • 2014
  • Model verification and validation (V&V) is a current research topic to build computational models with high predictive capability by addressing the general concepts, processes and statistical techniques. The hypothesis test for validity check is one of the model validation techniques and gives a guideline to evaluate the validity of a computational model when limited experimental data only exist due to restricted test resources (e.g., time and budget). The hypothesis test for validity check mainly employ Type I error, the risk of rejecting the valid computational model, for the validity evaluation since quantification of Type II error is not feasible for model validation. However, Type II error, the risk of accepting invalid computational model, should be importantly considered for an engineered products having high risk on predicted results. This paper proposes a technique named as the response-adaptive experimental design to reduce Type II error by adaptively designing experimental conditions for the validation experiment. A tire tread block problem and a numerical example are employed to show the effectiveness of the response-adaptive experimental design for the validity evaluation.

  • PDF

Determination of measuring time for decision of heavy metal ion concentration in Square Wave Voltammetry with FPGA (FPGA를 이용한 네모파 전압전류법의 계측시간 분석)

  • Lee, Jaechoon
    • Journal of Korea Society of Digital Industry and Information Management
    • /
    • v.12 no.4
    • /
    • pp.25-31
    • /
    • 2016
  • In this research, to analyze the concentration of heavy metal ions in water, we tried to find the measuring time at which the faradaic electric currents flowing by the pure oxidation-reduction reaction from the pushing up mercury electrode of the stripping scan square wave voltammetry(SV+SWV) methods system becomes larger than the capacitance electric current. In order to do this, a method for analyzing signals using FPGA has been designed and we conducted 120 experiments using it. As a result, when the frequency of the square wave is 40Hz, The valid potential-current signal was measured from 96.6667% to 96.7155% of the end of the pulse of the forward and reverse, and the optimal signal was measured at 96.6667%. In addition, the experiment was carried out 40 times by changing the pulse height of the square wave from 10Mv to 40Mv. As a result, at a size smaller than 40Mv, there is little change in the magnitude of the potential-current, and an invalid signal was generated when it is out of this size.

Performance Improvement of Cert-Validation of Certification based on FM Subcarrier Broadcasting (FM방식을 이용한 인증서 유효성 검증의 성능 향상)

  • 장홍종;이성은;이정현
    • Journal of the Korea Institute of Information Security & Cryptology
    • /
    • v.12 no.3
    • /
    • pp.3-13
    • /
    • 2002
  • There are cases that revoke the certification because of disclosure of private key, deprivation of qualification and the expiration of a term of validity on PKI. So, a user has to confirm the public key whether valid or invalid in the certification. There are many methods such as CRL, Delta-CRL, OCSP for the cert-validation of certification. But these methods have many problems, which cause overload traffic on network and the CRL server because of realtime processing for cert-validation of certification. In this paper we proposed cert-validation of certification improvement method based on FM Subcarrier Broadcasting, which solved problems that are data integrity by different time between transmission and receiving for CRL, and overload traffic on network and the CRL server the realtime management.