• Title/Summary/Keyword: time dependence

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A Study on the magnetization of metal orthopedic prosthesis in magnetic resonance imaging (자기공명 영상장치에서 정형보철금속의 자화(磁化)에 관한 연구)

  • Kim, Hyeong-Gyun;Song, Duk-Chung;Choi, Seong-Dae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.4
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    • pp.34-39
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    • 2013
  • For orthopedic artificial metal stainless steel, the magnetization of the magnetic field due to the presence of the titanium was to observe the change. Magnetic field meter (Tesla meters) a certain distance (ISO Centre) 1.5 Tesla magnetic field, the magnetization in the center with the passage of time were measured. Therefore, these artificial metal clip shape and magnetization of the sample size to produce a ferromagnetic material for comparison is the experimental dependence. For comparison of the experimental dependence of the magnetization, thereby producing a test piece size such as shaping prosthetic metal Clip is a ferromagnetic material. The experimental results, the metal orthopedic implants, there was no change in the magnetization indicated by ferromagnetic material in its natural state. However, in a magnetic field of 1.5T (Tesla), showed a sensitivity that is magnetized rapidly compared to the ferromagnetic material. In conclusion, high in the order of Clip, Stainless, of Titanium, the degree of dependence of the magnetization intensity of magnetization was the order Stainless, Titanium, of Clip in a magnetic field.

A Case of Seizures after Zolpidem Withdrawal (고용량 졸피뎀 복용 중단 이후 발생한 경련발작 1례)

  • Moon, Hyung Jun;Lee, Jung Won;Yoo, Byeong Dae
    • Journal of The Korean Society of Clinical Toxicology
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    • v.11 no.2
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    • pp.127-129
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    • 2013
  • The imidazopyridine, zolpidem, a non-benzodiazepine hypnotic drug, is widely-prescribed for insomnia. It is regarded as a good alternative to benzodiazepine because of the reduced possibility for abuse and development of dependence. However, more recently, due to the reduced possibility for abuse and development of dependence, it is regarded as a good alternative to benzodiazepine. adverse effects of zolpidem have been recognized. The objective of this report is to provide information on the potential for occurrence of benzodiazepine-like withdrawal seizure in patients who chronically take zolpidem continually. We present and discuss a case of seizure after sudden interruption of the protracted use of an abusively high dose of zolpidem. Zolpidem may not be the ideal drug for longterm pharmacotherapeutic management of insomnia. Clinicians should administer zolpidem at a low-dose for a short period of time for prevention of drug abuse and dependence and the potential for occurrence of benzodiazepine- like withdrawal seizure.

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The U.S. Contagion Effects on Foreign Direct Investment Flows in Developing Countries

  • HEMA, Itsarawadee;OSATHANUNKUL, Rossarin
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.4
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    • pp.55-67
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    • 2021
  • This study aims to measure the lower tail dependence as risk contagion from the U.S. economy to 18 developing countries affecting FDI inflows using time-series data from 2005 to 2019. Firstly, we utilize four dynamic copula models, namely, Student-t, Clayton, rotated survival Gumbel, and rotated survival Joe, to measure the tail dependence structure between the U.S. and each developing country's real GDP growth. Secondly, we use the regression model to explore the contagion effects on FDI inflows. The results show that there is evidence of the tail dependence between the U.S and developing economies, indicating the presence of the contagion effects. Primarily, we observe that the degree of contagion effects of the global financial crisis varies across countries; a strong impact is observed in Chinese, South African, Russian, Colombian, and Mexican economic growth. Furthermore, we found significant contagion risk affecting FDI inflows positively in China, Indonesia, Columbia, Morocco, and negatively in the Philippines, Bulgaria, and South Africa. This study demonstrates the usefulness of the copulas model in terms of examining contagion. Our findings shed light on the influence of sound policies and regulations to cope with both positive and negative consequences of the contagion on the capital movement.

The Data Processing Method for Small Samples and Multi-variates Series in GPS Deformation Monitoring

  • Guo-Lin, Liu;Wen-Hua, Zheng;Xin-Zhou, Wang;Lian-Peng, Zhang
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.185-189
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    • 2006
  • Time series analysis is a frequently effective method of constructing model and prediction in data processing of deformation monitoring. The monitoring data sample must to be as more as possible and time intervals are equal roughly so as to construct time series model accurately and achieve reliable prediction. But in the project practice of GPS deformation monitoring, the monitoring data sample can't be obtained too much and time intervals are not equal because of being restricted by all kinds of factors, and it contains many variates in the deformation model moreover. It is very important to study the data processing method for small samples and multi-variates time series in GPS deformation monitoring. A new method of establishing small samples and multi-variates deformation model and prediction model are put forward so as to resolve contradiction of small samples and multi-variates encountered in constructing deformation model and improve formerly data processing method of deformation monitoring. Based on the system theory, a deformation body is regarded as a whole organism; a time-dependence linear system model and a time-dependence bilinear system model are established. The dynamic parameters estimation is derived by means of prediction fit and least information distribution criteria. The final example demonstrates the validity and practice of this method.

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Evaluation of Time-Temperature Integrators (TTIs) with Microorganism- Entrapped Microbeads Produced Using Homogenization and SPG Membrane Emulsification Techniques

  • Mijanur Rahman, A.T.M.;Lee, Seung Ju;Jung, Seung Won
    • Journal of Microbiology and Biotechnology
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    • v.25 no.12
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    • pp.2058-2071
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    • 2015
  • A comparative study was conducted to evaluate precision and accuracy in controlling the temperature dependence of encapsulated microbial time-temperature integrators (TTIs) developed using two different emulsification techniques. Weissela cibaria CIFP 009 cells, immobilized within 2% Na-alginate gel microbeads using homogenization (5,000, 7,000, and 10,000 rpm) and Shirasu porous glass (SPG) membrane technologies (10 μm), were applied to microbial TTIs. The prepared micobeads were characterized with respect to their size, size distribution, shape and morphology, entrapment efficiency, and bead production yield. Additionally, fermentation process parameters including growth rate were investigated. The TTI responses (changes in pH and titratable acidity (TA)) were evaluated as a function of temperature (20℃, 25℃, and 30℃). In comparison with conventional methods, SPG membrane technology was able not only to produce highly uniform, small-sized beads with the narrowest size distribution, but also the bead production yield was found to be nearly 3.0 to 4.5 times higher. However, among the TTIs produced using the homogenization technique, poor linearity (R2) in terms of TA was observed for the 5,000 and 7,000 rpm treatments. Consequently, microbeads produced by the SPG membrane and by homogenization at 10,000 rpm were selected for adjusting the temperature dependence. The Ea values of TTIs containing 0.5, 1.0, and 1.5 g microbeads, prepared by SPG membrane and conventional methods, were estimated to be 86.0, 83.5, and 76.6 kJ/mol, and 85.5, 73.5, and 62.2 kJ/mol, respectively. Therefore, microbial TTIs developed using SPG membrane technology are much more efficient in controlling temperature dependence.

Extending Application of the 'Hardcore' Definition to Smokeless Tobacco Use: Estimates from a Nationally Representative Population in India and its Implications

  • Jena, Pratap Kumar;Bandyopadhyay, Chandan;Mathur, Manu Raj;Das, Sagarika
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.5959-5963
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    • 2012
  • Background: The term 'hardcore' has been applied to use of smoking tobacco and generally referred to as the inability or unwillingness of regular smokers to quit. The component constructs of hardcore except nicotine dependence are product neutral. With the use of 'time to first chew' as a measure of nicotine dependence, hardcore definition can be extended to characterize smokeless tobacco users. Hardcore users respond less to tobacco cessation interventions, and are prone to tobacco induced diseases including cancer. Thus identifying hardcore users would help in estimate the burden of high risk population for tobacco induced diseases. Smokeless tobacco use is predominant and accounts for more than 50% of oral cancer in India. Hence, hardcore chewing information could be used for planning of tobacco and cancer control interventions. The objective of this study was to assess the prevalence and associated factors of hardcore smokeless tobacco use in India. Materials and Methods: Global Adult Tobacco Survey (GATS)-India 2010 data were analyzed to quantify hardcore smokeless tobacco use in India with following five criteria: (1) current daily smokeless tobacco use; (2) no quit attempt in the past 12 months of survey or last quit attempt of less than 24 hours duration; (3) no intention to quit in next 12 months or not interested in quitting; (4) time to first use of smokeless tobacco product within 30 minutes of waking up; and (5) knowledge of smokeless tobacco hazards. Results: The number of hardcore smokeless tobacco users among adult Indians is estimated to be 5% (39.5 million). This group comprises 23.2% of daily smokeless tobacco users. The population prevalence varied from 1.4-9.1% across different national regions of India. Logistic regression modeling indicated age, education and employment status to be the major predictors of hardcore smokeless tobacco use in India. Conclusions: The presence of a huge number (39.5 million) of hardcore smokeless tobacco users is a challenge to tobacco control and cancer prevention in India. There is an unmet need for a universal tobacco cessation programme and intensification of anti-tobacco education in communities.

Development of Range-Dependent Ray Model for Sonar Simulator (소나 시뮬레이터용 거리 종속 음선 모델 개발)

  • Jung, Young-Cheol;Lee, Keunhwa;Seong, Woojae;Kim, Hyoung-Rok
    • The Journal of the Acoustical Society of Korea
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    • v.33 no.3
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    • pp.163-173
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    • 2014
  • Sound propagation algorithm for a sonar simulator is required to run in real-time and should be able to model the range and depth dependence of the Korean ocean environments. Ray model satisfies these requirements and we developed an algorithm for range-dependent ocean environments. In this algorithm, we considered depth-dependence of sound speed through rays based on a rectangular cell method and layer method. Range-dependence of sound speed was implemented based on a split-step method in the range direction. Eigen-ray is calculated through an interpolation of ray bundles and Gaussian interpolation function was used. The received time signal of sonar was simulated by Fourier transform of eigen-ray solution in the frequency domain. Finally, for the verification of proposed algorithm, we compared the results of transmission loss with other validated models such as BELLHOP, SNUPE, KRAKEN and OASES, for the Pekeris waveguide, wedge, and deep ocean environments. As a result, we obtained satisfactory agreements among them.

Time Series Modelling of Air Quality in Korea: Long Range Dependence or Changes in Mean? (한국의 미세먼지 시계열 분석: 장기종속 시계열 혹은 비정상 평균변화모형?)

  • Baek, Changryong
    • The Korean Journal of Applied Statistics
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    • v.26 no.6
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    • pp.987-998
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    • 2013
  • This paper considers the statistical characteristics on the air quality (PM10) of Korea collected hourly in 2011. PM10 in Korea exhibits very strong correlations even for higher lags, namely, long range dependence. It is power-law tailed in marginal distribution, and generalized Pareto distribution successfully captures the thicker tail than log-normal distribution. However, slowly decaying autocorrelations may confuse practitioners since a non-stationary model (such as changes in mean) can produce spurious long term correlations for finite samples. We conduct a statistical testing procedure to distinguish two models and argue that the high persistency can be explained by non-stationary changes in mean model rather than long range dependent time series models.

Transform Nested Loops into MultiThread in Java Programming Language for Parallel Processing (자바 프로그래밍에서 병렬처리를 위한 중첩 루프 구조의 다중스레드 변환)

  • Hwang, Deuk-Young;Choi, Young-Keun
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.8
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    • pp.1997-2012
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    • 1998
  • It is necessary to find out the parallelism in tlle sequential Java program to execute it on the parallel machine. The loop is a fundamental source to exploit parallelism as it process a large portion of total execution time in sequential Java program on the parallel machine. However, a complete parallel execution can hardly be achieved due to data dependence. This paper proposes the method of exploiting the implicit parallelism by structuring a dependence graph through the analysis of data dependence in the existing Java programming language having a nested loop structure. The parallel code generation method through the restructuring compiler and also the translation method of Java source program into multithread statement. which is supported by the Java programming language itself, are proposed here. The perforance evaluatlun of the program translaed into the thread statement is conducted using the trip cunt of loop and the trip Count of luop and the thread count as parameters The resttucturing compiler provides efficient way of exploiting parallelism by reducing manual overhead conveliing sequential Java program into parallel code. The execution time for the Java program as a result can be reduced un the parallel machine.

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A Study on the Object-Oriented Program Slicing using Module Class Dependency Graph (모듈 클래스 종속 그래프를 이용한 객체지향 프로그램 슬라이싱에 관한 연구)

  • Kim, Un-Yong;Jeong, Gye-Dong;Choe, Yeong-Geun
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.7
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    • pp.1805-1816
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    • 1999
  • This paper presents the Module Class Dependency Graph for expressing the dependency relations between classes effectively. The object-oriented language is developed independently at design time, and consists of relationship between classes. Therefore we need to consider these characteristics of independence, and to express effectively the relation of classes which is existed in class hierarchy. In the System Dependence Graph and Class Dependence Graph, the relationship of classes is not expressed. To express the class relationship, we propose the Module Class Dependence Graph, and we verify the effectiveness of this method applying to object constructor, inheritance relationship and dynamic binding. Also, we presents the expressing method of parameter to identify the member data of classes. Using this Module Class Dependency Graph, we can analyze the relationship of module class correctly at design time. This method can be applied to reverse engineering, testing, visualization and other various fields to analyze system.

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