• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.739-742
• /
• 2019

In this paper, we propose enhanced DAP(Dose Area Product). The development of enhanced DAP proposed in this paper has optimized the area dose meter that was developed previously. The development of enhanced DAP performed Optimized design of charge integrator and ADC circuit, optimization of line transceiver for RS-485 communication, optimization of display circuit, and optimization of PC-based control program for interlocking and aging. As a result of evaluating the performance of the proposed system in an accredited testing laboratory, Radiation dose dependence and Radiation quality dependence were measured to be 4.2%, which is below ${\pm}15%$ of international standard. Energy range/Tube voltage was confirmed in the range of 30~150kV. The sensitivity difference between sensor field and sensor field area dose sensitivity was measured to be 4.3%, and it was confirmed that it operates normally under ${\pm}15%$ of international standard. In order to measure the reproducibility of the area dosimeter, it was confirmed that it was 0% and it was operated normally at less than 2% of IEC60580 recommendation. Digital resolution was confirmed to be a minimum unit of $0.01{\mu}Gy{\cdot}m^2$ within the error range for the reference dose per hour.

• Korean Journal of Biological Psychiatry
• /
• v.24 no.2
• /
• pp.68-74
• /
• 2017

Objectives It is well known that problem drinking is associated with alterations of brain structures and functions. Brain functions related to alcohol consumption can be determined by the resting state functional connectivity in various resting state networks (RSNs). This study aims to ascertain the alcohol effect on the structures forming predetermined RSNs by assessing their cortical thickness. Methods Twenty-six abstinent male patients with alcohol dependence and the same number of age-matched healthy control were recruited from an inpatient mental hospital and community. All participants underwent a 3T MRI scan. Averaged cortical thickness of areas constituting 7 RSNs were determined by using FreeSurfer with Yeo atlas derived from cortical parcellation estimated by intrinsic functional connectivity. Results There were significant group differences of mean cortical thicknesses (Cohen's d, corrected p) in ventral attention (1.01, < 0.01), dorsal attention (0.93, 0.01), somatomotor (0.90, 0.01), and visual (0.88, 0.02) networks. We could not find significant group differences in the default mode network. There were also significant group differences of gray matter volumes corrected by head size across the all networks. However, there were no group differences of surface area in each network. Conclusions There are differences in degree and pattern of structural recovery after abstinence across areas forming RSNs. Considering the previous observation that group differences of functional connectivity were significant only in networks related to task-positive networks such as dorsal attention and cognitive control networks, we can explain recovery pattern of cognition and emotion related to the default mode network and the mechanisms for craving and relapse associated with task-positive networks.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.12
• /
• pp.5959-5963
• /
• 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.

• The Journal of Internal Korean Medicine
• /
• v.28 no.2
• /
• pp.294-303
• /
• 2007

Objectives : We are aimed to identify anti-tumor effects of realgar on some kinds of cancer cells through molecular biologic methods. Materials & Methods : We used 5 kinds of cancer cell lines: lung cancer cells(A549). stomach cancer cells(KATO) and neuroglioma cells(SUN-1118. U-87MG, U-373MG). We injected the boiled extracts of realgar $50{\mu}g$. $100{\mu}g$ to cultural media( ml )for 24 hours. We measured the killing effects on 5 kinds of cancer cells through inverted and fluorescence microscope, the suppressive effects on viability of those cells via XTT assay and the effects on the revelation of Bax and Bcl-2 proteins related to apoptosis by western blotting. Results : In the changes of morphology, the extracts of realgar showed more significant killing effects on all cancer cells. especially KATO, SNU-1118, U-87MG, U-373MG, than the control group with dose dependence, which was statistically significant. In XTT assay, the extracts of realgar showed more suppressive effects on viability of all cancer cells, especially KATO and U-373MG, than the control group with dose dependence, which was statistically significant. In the revelation of proteins related to apoptosis, the extracts of realgar increased the level of Bax and decreased that of Bcl-2 in all cancer cells with dose dependence. Conclusions : We identified that realgar had more anti-tumor effects on stomach cancer and neuroglioma than on lung cancer in the experiments above. However, these basic experiments were performed in vitro. We hope the anti-tumor effects of realgar will be practically identified through more progressive research.

• Journal of the Korea Safety Management & Science
• /
• v.14 no.3
• /
• pp.193-205
• /
• 2012

Since manufacturing and supplying corporations today come to view their practice of SCM as important, it becomes essential to analyze and control the structural relationship between the information sharing among corporations and the performances resulting from their practice of SCM. It is thus the purpose of this paper to examine the factors that may prompt corporations to implement SCM by means of analyses into the relationship between information sharing and practice of SCM which corporations should lay stress on as well as the relationship between financial and non-financial performances of corporations. The findings of the study can be summed up as follows: First, as for the relationship between information sharing among and practice of SCM by corporations, information sharing among corporations turned out to affect such factors of implementing their SCM as trust, commitment mutual dependence. Consequently, corporations are requested to endeavor to implement SCM itself faithfully if they really aim to achieve their performances by practice of SCM and, at the same time, to make efforts to obtain understanding and support for information sharing among themselves. Second, from the analysis of the relationship between SCM and financial as well as non-financial performances of corporations, it was found that trust, a factor of SCM practice, had influence upon non-financial performances of corporations, but not upon their financial performances, while commitment and mutual dependence affected both financial and non-financial achievements of corporations. Therefore, it was made clear from the analysis that the decision and systematic control of SCM activities which best suit to a corporation play an important role in improving its financial and non-financial performances, because they greatly depend on the implementing extent of SCM factors such as trust, commitment and mutual dependence among corporations.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1289-1291
• /
• 1994

Dielectric properties of $C_{22}$-Quinolium(TCNQ) Langmuir-Blodgett (LB) films were studied as a function of frequency(10Hz-13MHz) and annealing temperature($20{\sim}240^{\circ}C$). A complex dielectric constant ${\epsilon}^*={\epsilon}'-i{\epsilon}"$, in general, shows the frequency dependence of orientational polarization in the measured frequency range. A dielectric permittivity ${\epsilon}'$ at 10Hz is around 8.2 and decreases very slowly as the frequency increases up to 1 MHz, and then suddenly drops above this frequency, while a dielectric loss factor ${\epsilon}"$ reaches a maximum near 1 MHz. Its annealing temperature dependence at 10Hz shows that ${\epsilon}'$ and ${\epsilon}"$ increase as the temperature increases upto $180^{\circ}C$, even though there is a little drop near $120{\sim}160^{\circ}C$. Both ${\epsilon}'$ and ${\epsilon}"$ drop quickly above $180^{\circ}C$. which may be thought of a destruction of the LB films. Another fact of the annealing temperature dependence of the dielectric constant is an occurrence of the new dielectric dispersion below 100Hz. This low frequency dispersion is getting clear above $80^{\circ}C$.

• Journal of applied mathematics & informatics
• /
• v.25 no.1_2
• /
• pp.35-50
• /
• 2007

In this work, optimal harvesting policy for the predator-prey system of three species with age-dependent and diffusion is discussed. Existence and uniqueness of non-negative solution to the system are investigated by using the fixed point theorem. The existence of optimal control strategy is discussed and optimality conditions are obtained. Our results extend some known criteria.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.187-190
• /
• 1995

A method is proposed which searches for optimal structures of Neural Networks (NN) using Genetic Algorithm (GA). The purpose of the method lies in not only finding an optimal NN structure but also leading us to the goal of self-organized control system that acquires its structure and its functionality by itself depending on its environment.

• Communications of the Korean Mathematical Society
• /
• v.35 no.4
• /
• pp.1329-1352
• /
• 2020

In this paper we consider a class of nonlinear evolution equations on infinite dimensional Banach spaces driven by vector measures. We prove existence and uniqueness of solutions and continuous dependence of solutions on the control measures. Using these results we prove existence of optimal controls for Bolza problems. Based on this result we present necessary conditions of optimality.

• Proceedings of the Optical Society of Korea Conference
• /
• 2008.07a
• /
• pp.329-330
• /
• 2008

We experimentally demonstrate resonant-wavelength control of a series of an Si-based photonic crystal nanocavity. The cavities show a linear dependence on these parameters, a 1 nm increase of lattice constant leading to 4.2 nm increase of the resonant wavelength. The results have a small standard deviation of wavelength 1.1 nm between samples on a single chip.