• Tunnel and Underground Space
• /
• v.33 no.5
• /
• pp.414-424
• /
• 2023

In this study, a total of 326 data on a variety of geometric parameters of pick cutters and the corresponding cuttable rock conditions were collected and built as a database. Statistical analysis of the database showed that there is a significant positive correlation between the parameters that define the geometry of a pick cutter, especially between the parameters related to the length of a pick cutter and the geometry of a tungsten carbide insert. The diameter of a pick cutter shaft was also strongly correlated with the geometry of the inserts. On the other hand, it was difficult to find a clear correlation between the parameters for the rock conditions defined by the four conditions and the geometric parameters of pick cutters, which may be due to the uncertainty of the rock mass and the fact that the application of a pick cutter is presented as a range rather than a numerical single value. However, the mean values of geometric parameters of pick cutters tend to increase as a rock mass becomes harder. However, the pick length parameters are found to decrease as a rock mass becomes harder, which may be a way to reduce the moments that can occur when using long pick cutters in a hard rock condition.

• ETRI Journal
• /
• v.34 no.6
• /
• pp.858-868
• /
• 2012

In this paper, stochastic models for the cross-correlation of multiple channels are established based on measurement data collected using a wideband multiple-input multiple-output relay Band Exploration and Channel Sounder system at 3.7 GHz. We propose models for the cross-correlation characteristics of large-scale parameters (LSPs) between two links, that is, the base station and mobile station (MS) link and the relay station and MS link. The LSPs include shadow fading, Rician K-factor, delay spread, angle spread of arrival, and angle spread of departure. Furthermore, models are established for the cross-correlation of the small-scale fading in the impulse responses of two links. The statistics of these model parameters are investigated as functions of geometrical features of the multilink. They are extracted from a large amount of cross-correlation observations, which are obtained in three measurement sites along more than one hundred measurement routes. These models can be used together with the standard single-link channel models for the generation of correlated components, for example, path clusters, in two separate channels.

• Journal of Forest and Environmental Science
• /
• v.28 no.3
• /
• pp.170-178
• /
• 2012

Dipterocarps or Dipterocarpaceae is a commercially important timber producing and dominant keystone tree family in the rain forests of Borneo. Borneo's landscape is changing at an unprecedented rate in recent years which affects this important biodiversity. This paper attempts to model the natural occurrence (distribution including those areas with natural forests before being converted to other land uses as opposed to current distribution) of dipterocarp species in Sarawak which is important for forest biodiversity conservation and management. Local modeling method of Inverse Distance Weighting was compared with commonly used statistical method (Binary Logistic Regression) to build the best natural distribution models for three genera (12 species) of dipterocarps. Database of species occurrence data and pseudoabsence data were constructed and divided into two halves for model building and validation. For logistic regression modeling, climatic, topographical and edaphic parameters were used. Proxy variables were used to represent the parameters which were highly (p>0.75) correlated to avoid over-fitting. The results show that Inverse Distance Weighting produced the best and consistent prediction with an average accuracy of over 80%. This study demonstrates that local interpolation method can be used for the modeling of natural distribution of dipterocarp species. The Inverse Distance Weighted was proven a better method and the possible reasons are discussed.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.19
• /
• pp.8367-8370
• /
• 2014

The relationship between caveolin-1 (Cav-1) and clinicopathological characteristics of gastric cancer is controversial, although Cav-1 plays an important role in tumor metastasis. To evaluate the clinicopathological and prognostic value of expression in patients with gastric cancer, a meta-analysis was performed to investigate the impact on clinicopathological parameters and prognosis in gastric cancer cases. Studies assessing these parameters for Cav-1 in gastric cancer were identified up to June 2014. Finally, a total of six studies met the inclusion criteria. Our combined results showed that Cav-1 expression was significantly associated with the Lauren classification (pooled OR=0.603, 95% CI: 0.381-0.953, P=0.030). Furthermore, we found that Cav-1 expression predicted a better overall survival in gastric cancer patients (pooled OR=0.590, 95% CI: 0.360-0.970, P=0.038, fixed-effect). In conclusion, the overall data of the present meta analysis showed that Cav-1 expression was not correlated with clinicopathological features except for the Lauren classification. Simultaneously, Cav-1 overexpression predicted a better overall survival in gastric cancer. Cav-1 expression in tumors is a candidate positive prognostic biomarker for gastric cancer patients.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.126-126
• /
• 2009

Noninvasive plasma diagnostic technique is introduced to analyze and characterize HICP (Helmholtz Inductively Coupled Plasma) source during the plasma etching process. The HICP reactor generates plasma mainly through RF source power at 13.56MHz RF power and RF bias power of 12.56MHz is applied to the cathode to independently control ion density and ion energy. For noninvasive sensors, the RF sensor and the OES (Optical emission spectroscopy) were employed since it is possible to obtain both physical and chemical properties of the reactor with plasma etching. The plasma impedance and optical spectra were observed while altering process parameters such as pressure, gas flow, source and bias power during the poly silicon etching process. In this experiment, we have found that data measured from these noninvasive sensors can be correlated to etch results. In this paper, we discuss the relationship between process parameters and the measurement data from RF sensor and OES such as plasma impedance and optical spectra and using these relationships to analyze and characterize H-ICP source.

• Ocean Science Journal
• /
• v.43 no.2
• /
• pp.67-79
• /
• 2008

We investigated the relationship between mesoscale spatial distribution of environmental parameters (temperature, salinity, and sigma-t), chlorophyll-a concentration and mesozooplankton in the Yellow Sea during May 1996, 1997, and 1998, with special reference to Yellow Sea Bottom Cold Water (YSBCW). Adult calanoid copepods, Calanus sinicus, Paracalanus parvus s.l., Acartia omorii, and Centropages abdominalis were isolated by BVSTEP analysis based on the consistent explainable percentage (-32.3%) of the total mesozooplankton distributional pattern. The copepods, which accounted for 60 to 87% of the total abundances, occupied 73-78% of the copepod community. The YSBCW consistently remained in the northern part of the study area and influenced the spatial distribution of the calanoid copepods during the study periods. Abundances of C. sinicus and P. parvus s.l., which were high outside the YSBCW, were positively correlated with the whole water average temperature (p<0.01). In contrast, the abundances of C. abdominalis and A. omorii, which were relatively high in the YSBCW, were associated with the integrated chl-a concentration based on factor analysis. These results indicate that the YSBCW influenced the mesoscale spatial heterogeneity of average temperature and integrated chl-a concentration through the water column. This consequently affected the spatial distribution pattern of the dominant copepods in association with their respective preferences for environmental and biological parameters in the Yellow Sea during spring.

• Journal of Nutrition and Health
• /
• v.26 no.3
• /
• pp.313-324
• /
• 1993

Sister chromatid exchange(SCE) has recently become a common cytogenic assay system for detecting exposure to chemical mutagens and carcinogens. One application of SCE is the monitoring of populations believed to be exposed to such agents. A cross-sectional study of SCE frequency in peripheral blood lymphocytes from 40 college students aged 18 to 26 years was conducted. The effects of cigarette smoking alcohol and coffee consumption, dietary and environmental factors on SCE were assessed. A mean spontaneous SCE per cell for the smokers(4.88$\pm$0.17). The SCE levels of the smokers were associated with the personal smoking amount ; the observed increase in the SCE frequency correlated with the number of cigarettes smoked per day (P<0.05). There was no effect of age on SCE. There were positive linear relationship between SCE and food frequency score of meat and fish group (P<0.05) or instant food group(P<0.01) in non-smokers. But in smokers, a significant inverse association between SCE and food frequency score of green and yellow vegetable group(P<0.05). Alcohol intake produced a significant increase(P<0.01) of SCE in comparison with the mean SCE for those not drinking alcohol in combine subjects. Other dietary parameters, including coffee intake, use of artificial sweetners and processed foods, did not show any increase in SCE. SCEs were inversely related to blood glucose and serum cholesterol levels of the combine subjects. No significant correlations were found between SCE frequencise and any other hematological parameters of the subjects.

• Computers and Concrete
• /
• v.10 no.6
• /
• pp.557-573
• /
• 2012

This paper discusses the combined application of two different techniques, Neural Networks (NN) and Principal Component Analysis (PCA), for improved prediction of concrete properties. The combination of these approaches allowed the development of six neural networks models for predicting slump and compressive strength of concrete with mineral additives such as blast furnace slag, fly ash and silica fume. The Back-Propagation Multi-Layer Perceptron (BPMLP) with Bayesian regularization was used in all these models. They are produced to implement the complex nonlinear relationship between the inputs and the output of the network. They are also established through the incorporation of a huge experimental database on concrete organized in the form Mix-Property. Thus, the data comprising the concrete mixtures are much correlated to each others. The PCA is proposed for the compression and the elimination of the correlation between these data. After applying the PCA, the uncorrelated data were used to train the six models. The predictive results of these models were compared with the actual experimental trials. The results showed that the elimination of the correlation between the input parameters using PCA improved the predictive generalisation performance models with smaller architectures and dimensionality reduction. This study showed also that using the developed models for numerical investigations on the parameters affecting the properties of concrete is promising.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.14 no.5
• /
• pp.472-485
• /
• 1989

This paper represents the occurrence structure of the timing variation of TV horizontal synchronizing pulse(H-sync pulse) in mobile TV reception. Fluttering ghost is caused by timing varations of the H-sync pulse and is due to frequency elective fading in a multipath propagation envoronment. H-sync timing fluctuations, and hence, fluttering ghost are directly correlated with the multipath parameters, i.e., H-sync timing fluctuations reflect well the severity of the multipath environment. The occurrence structure of H-sync timtng fluctuation is analysed theoretically in relation to the multipath environnment. The occurrence structure of H-sync timing fluctuation is analysed theoretically in relation to the multipath parameters, assuming the two-ray propagation model. The H-sync timing fluctuation occurs with the variation in relative phase and /or D/U variation of long-delayed multipath waves.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.18
• /
• pp.8599-8604
• /
• 2016

Ovarian cancer is the main cause of mortality in gynecological malignancy and extensive studies have been conducted to study the underlying molecular mechanisms. The BRCA2 gene is known to be an important tumor suppressor in ovarian cancer, thereby BRCA2 alterations may lead to cancer progression. However, the BRCA2 gene is rarely mutated, and loss of function is suspected to be mediated by epigenetic regulation. In this study we investigated the methylation status and gene expression of BRCA2 in ovarian cancer patients. Ovarian cancer pateints (n=69) were recruited and monitored for 54 months in this prospective cohort study. Clinical specimens were used to study the in situ expression of aberrant BRCA2 proteins and the methylation status of BRCA2. These parameters were then compared with clinical parameters and overall survival rate. We found that BRCA2 methylation was found in the majority of cases (98.7%). However, the methylation status was not associated with protein level expression of BRCA2 (49.3%). Therefore in addition to DNA methylation, other epigenetic mechanisms may regulate BRCA2 expresison. Our findings may become evidence of BRCA2 inactivation mechanism through DNA methylation in the Indonesian population. More importantly, from multivariate analysis, BRCA2 expression was correlated with better overall survival (HR 0.32; p=0.05). High percentage of BRCA2 methylation and correlation of BRCA2 expression with overall survival in epithelial ovarian cancer cases may lead to development of treatment modalities specifically to target methylation of BRCA genes.