• Smart Structures and Systems
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• v.18 no.4
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• pp.643-662
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• 2016

The monitoring of structural integrity of pipeline tapered thread connections is of great significance in terms of safe operation in the industry. In order to detect effectively the loosening degree of tapered thread connection, an active sensing method using piezoceramic transducers was developed based on time reversal technique in this paper. As the piezoeramic transducers can be either as actuators or sensors to generate or detect stress waves, the energy transmission for tapered thread connection was analyzed. Subsequently, the detection principle for tapered thread connection based on time reversal was introduced. Finally, the inherent relationship between the contact area and tightness degree of tapered thread connection for the pipe structural model was investigated. Seven different contact area scenarios were tested. Each scenario was created by loosening connectors ranging from 3 turns to 4.5 turns in the right tapered threads when the contact area in the left tapered threads were 4.5 turns. The experiments were separately conducted with a highly noisy environment and various excitation signal amplitudes. The results show the focused peaks based on time reversal have the monotonously rising trend with the increase of the contact areas of tapered threads within an acceptable monitoring resolution for metal pipes. Compared with the energy method, the proposed time reversal based method to monitor tapered threads loosening demonstrates to be more robust in rejecting noise in Structural Health Monitoring (SHM) applications.

• Lingua Humanitatis
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• v.2 no.1
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• pp.7-42
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• 2002

This paper reexamines ideas about linguistic relativity in the light of new interest in the theoretical climate. The original idea is based on the incommensurability of the semantic structures of different languages. On this view, language, thought, culture are deeply interconnected, so that each language might be associated with it a distinctive world view. Throughout this work I utilize the historico-epistemological standpoint to dissect the conceptual structure of this principle. In the introduction I will of for a justification of choice of the theme. Section 1 will address some essential definition of the linguistic principle and insist on the necessity to elaborate a typological spectrum of relativism and universalism. In the second section some important landmarks of linguistic relativity were marked from Plato to Humboldt via Condillac and Herder. 1 will subdivide the relativity hypothesis into 3 theses which are interlated. In the final section the epistemological structure of the linguistic principle will be analysed in some detail by providing my exposition of Sapir-Whorf hypothesis. By way of conclusion I will present the works of Wierzbicka who demonstrated the lexicons of different languages suggest different conceptual universes. By rejecting analytical tools derived from the English language she proposed instead a natural semantic metalanguage based on lexical universals, which is made up of universal semantic primitives. In this paper we attempted to construct a general problematics of linguistic relativity, focolizing on the Sapir-Whorf hypothesis. We devided this very problematic question into its ontological and epistemological dimensions. In particular the ambivalance of Whorf's relativity is discussed in some detail. Also, an archeological survey of this subtle question on the relation between language, thinking and culture was provided. (from Aristotle to Humboldt, via Condillac and Nitzche). In conclusion this investigation underlines the necessity of preparing the cultural linguistics to enlarge the scope of contempory linguistics.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.2 no.1
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• pp.24-31
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• 1991

It has long been accepted that test anxiety is developed by parent-child relationship. The purpose of this study was to investigate the parent influence on student's test anxiety. The Korean Form of Test Anxiety Inventory(TAI-K) and the Parent Attitude Scale were used. 481 primary school-and 500 high school students were participated in the study. The results were as follows ; 1) The parental factor identified as 'rejecting' was positively correlated with students' test anxiety, while the parental factor identified as 'rearing as self-controlled being' was negatively correlated. 2) The students who identified their parents as 'being achievement-oriented' reported significantly higher test anxiety than those who identified their parents as 'accepting'. Many studies also report that high test anxiety interferes with student's performance. Therefore, parents should accept and understand their children in order to alleviate test.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.19 no.3
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• pp.175-181
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• 2008

Objectives: This study was conducted to compare the mothers' rearing attitude of ADHD children and that of children with depressive disorder. Methods: The participant consisted of 58 school-aged children diagnosed as ADHD, 14 children diagnosed as depressive disorder based on DSM-IV criteria. Normal control group consisted of 34 school-aged children who are free of any diagnosis of psychiatric disorders. Parental Acceptance-Rejection Questionnaire, Parenting Style Questionnaire, Children's Depression Inventory, Marital Satisfaction Scale, Beck's Depression Inventory were administered to all children and their mothers. Results: The parents of ADHD children showed more aggressive/hostile, neglecting/indifferent and less warm/affectionate parenting styles to their children than those of the depression and control groups. The depressive group perceived their parents as more rejecting than the control groups. Conclusion: The externalizing symptoms of ADHD might provoke parental distress and make it difficult for the parents to show positive rearing attitude toward their children. The depressive children might be more sensitive and perceptive to the negative sign of their parents' rearing attitude.

• Journal of the Korean Data and Information Science Society
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• v.15 no.4
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• pp.743-752
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• 2004

In this paper, we develop the Bayesian model selection procedure using the reference prior for comparing two nested model such as the independent and intraclass models using the distance or divergence between the two as the basis of comparison. A suitable criterion for this is the power divergence measure as introduced by Cressie and Read(1984). Such a measure includes the Kullback -Liebler divergence measures and the Hellinger divergence measure as special cases. For this problem, the power divergence measure turns out to be a function solely of $\rho$, the intraclass correlation coefficient. Also, this function is convex, and the minimum is attained at $\rho=0$. We use reference prior for $\rho$. Due to the duality between hypothesis tests and set estimation, the hypothesis testing problem can also be solved by solving a corresponding set estimation problem. The present paper develops Bayesian method based on the Kullback-Liebler and Hellinger divergence measures, rejecting $H_0:\rho=0$ when the specified divergence measure exceeds some number d. This number d is so chosen that the resulting credible interval for the divergence measure has specified coverage probability $1-{\alpha}$. The length of such an interval is compared with the equal two-tailed credible interval and the HPD credible interval for $\rho$ with the same coverage probability which can also be inverted into acceptance regions of $H_0:\rho=0$. Example is considered where the HPD interval based on the one-at- a-time reference prior turns out to be the shortest credible interval having the same coverage probability.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.175-182
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• 2012

The scattered radiation always occurs when X-ray strikes the object. To absorb the scattered X-rays, the antiscatter grids are used, however these grids images are superimposed in the projection radiography images. When those images are displayed on the monitor, moir$\acute{e}$ patterns are overlapped over the images and disturb the anatomical informations. Most of the researches performed to date removed the grid noises by calculating or observing those frequencies in one dimensional frequency domain, two dimensional wavelet transform or Fourier transform. Those methods filtered not only the grid noises but also diagnostic informations. In this paper, we proposed the combined wavelet packet-Fourier method to remove the grid artifact in CR images. For the phantom image, the proposed method achieved from 5.2 to 7.4 dB better than others in SNR and for CR images by rejecting the grid noise bands effectively while leaving the remaining bands unchanged, the loss of images could get minimal results.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.57-63
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• 2013

The mission of a lot of satellites on geostationary orbit is the communication and/or the broadcasting. These satellites need a big power, so these have a large solar array. Recently, the new satellite for Earth environment monitoring is developing on geostationary orbit. The payload of Earth monitoring satellite requires better thermal condition on detector. Therefore this satellite uses a boom for the attitude stability instead of rejecting one-side solar array as a heat source. The other hand, it uses some momentum wheels being a more momentum capacity to control the large disturbance by solar pressure due to the asymmetric solar array configuration. In this paper, the analysis on the wheel allocation and the wheel off-loading for COMS is summarized and the results are verified by telemetry of COMS. COMS has no boom and a perfectly asymmetric solar array configuration, and it is operating well on geostationary orbit.

• Fashion & Textile Research Journal
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• v.18 no.5
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• pp.625-636
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• 2016

The purposes of this study were to investigate the effects of social appearance anxiety, negative body image, appearance importance on appearance management behavior and cosmetic surgery intention. For data collection, a questionnaire was administrated to 428 female college students in Gwangju City, Korea. The results were summarized as follows. To analysis the data, the SPSS 20.0 was used, and frequence analysis, descriptive statistical analysis, reliability analysis, regression analysis, F-test were conducted. The results were summarized as follows. First, social appearance anxiety turned out to have significant positive effect on appearance management behavior and cosmetic surgery intention. Second, negative body image had positive effect on appearance management behavior and cosmetic surgery intention. Third, appearance importance turned out to have significant effect on appearance management behavior and cosmetic surgery intention. The results of this study above suggest that it would be necessary to seek for measures to reduce individual's appearance anxiety, negative body image, and appearance importance. Especially, People should get the realization of the beautiful on the inside that includes personality is more important than having external beauty. And, it is considered that the requirements of the social effort and education through a school and a media as well as a family for reducing the individual's appearance anxiety, negative body image, and the serious consideration of the appearance as rejecting the discrimination based on appearance.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.330-336
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• 2014

Many industrial processes such as continuous stirred tank reactors(CSTRs), desalination plant, distillation columns, pH neutralization processes and so on exhibit highly nonlinear characteristic and time-varying behavior during operation. The control of such processes has been challenging to control engineers. Hence, a variety of forms of PID controllers and their tuning rules for industrial processes have been developed to guarantee the best performance. In this paper, a scheme that designs the practical PID controller with an anti-windup strategy incorporating with an evolutionary algorithm(EA) is presented for the concentration control of a nonisothermal CSTR. EA is used to tune the parameters of the overall PID control process with anti-windup by minimizing the integral of absolute error(IAE). Simulation works for reference tracking and disturbance rejecting performances and robustness to parameter changes show the feasibility of using the proposed method.

• The Korean Journal of Financial Management
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• v.22 no.2
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• pp.135-164
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• 2005

We analyze trade and balance records of 10,000 stock investment accounts of individual investors for the period of 1998 to 2003. Individual investors em an annual gross return of 12.3% while the KOSPI and the value weighted composite including KOSDAQ stocks yield 13.6% and 9.7% respectively during the same period. Net return performance is 8.3%, a drop of 5.3% mainly due to heavy trading. Individual investors' annual turnover amounts to over 270 percent. In an analysis of groups formed on the month's end position value, the performance of the top quintile is found comparable to the market while the rest yield significantly lower risk-adjusted returns than the market. We also find evidence rejecting the rational expectation model while supporting the overconfidence hypothesis which states overconfidence leads to a higher level of trading, resulting in poor performance. Individuals tilt their stock investment toward high-beta, small, and value stocks.