• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7129-7135
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• 2014

Background: In this study, we aimed to evaluate the growth inhibitory effect of the combination of ethaselen (BBSKE) and low fixed dose of selenite against A549 human non-small cell lung cancer cells in vitro. Materials and Methods: Growth inhibitory effects against A549 cells were determined by SRB assay. Combination index (CI) values were calculated based on Chou-Talalay median-effect analyses. Dose reduction index (DRI) values were applied to calculate dose reduction of selenite. Contents of free thiols and GSH were determined by DTNB assay and intracellular ROS levels by DCFH-DA fluorescence labeling. Results: Compared with BBSKE or selenite single treatment, the combined application of ethaselen and a low fixed dose of selenite shortened the onset time of sodium selenite, reduced $IC_{50}$ values, and increased the maximum inhibition rates, suggesting a possible molecular mechanism of the synergism. Obvious synergistic effects were observed after different times of combination treatment, especially after 24 h. Compared with selenite single treatment, dosage of selenite could be remarkably reduced in combination therapy to gain the same inhibitory effect on cell proliferation. Compared with BBSKE single treatment, the content of free thiols and GSH were significantly reduced and ROS levels greatly elevated in the combination group. For the combination treatment, cell viability increased as greater concentrations of GSH were added. Conclusions: All these results indicate that the combination treatment of BBSKE and selenite showed synergism to inhibit A549 cell proliferation in vitro, and also reduced the selenite dosage to mitigate its toxicity which is very meaningful for combination chemotherapy of lung cancer. The synergism was probably caused by the accelerated exhaustion of intracellular reductive substances, such as free thiols and GSH, which ultimately leads to enhanced oxidative stress and apoptosis.

• Journal of agricultural medicine and community health
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• v.27 no.1
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• pp.1-8
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• 2002

Pest control is required for protecting the food supply and for controlling disease vectors. Unfortunately, there is no perfectly safe form of pest control. Pesticides are commonly used for pest control. Pesticides are defined under the US Federal Insecticide Fungicide and Rodenticide Act(FIFRA) as any substance or mixture of substances intended to prevent, destroy, repel, or mitigate pests, and any substance or mixture of substances intended for use as a plant regulator, defoliant, or dessicant(40 CFR Part 152). Currently in the United States, there are 890 active ingredients registered as pesticides. Approximately one billion pounds of active ingredient are used in the US per year. Unlike most chemicals(anti-neoplastic and anti-micobial medications are the principal exceptions), pesticides are specifically designed to kill and cause harm. Because society allows these chemicals to be disseminated into the environment, it is important to monitor the health effects associated with these releases. This represents an important justification for establishing and maintaining surveillance systems for acute pesticide-related illness and injury. A comprehensive, national surveillance system for acute pesticide-related illness and injury does not currently exist in the US. Although the United States has several surveillance systems for this condition, none provide a complete understanding of the problem of acute pesticide-related illness and injury. The Toxic Exposure Surveillance System(TESS) and Bureau of Labor Statisitics(BLS) are useful for assessing magnitude and trends. The state-based surveillance systems are more useful for timely identification of outbreaks and emerging problems. Efforts are underway to increase the number of states that conduct surveillance, and to broaden the use of the standardized case definition to facilitate aggregation of data across states. Through such efforts, a comprehensive, national surveillance system may be attainable.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.1-7
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• 2004

The development of direct receiver techniques is expected to be a solution for future wideband or multi-band wireless systems based on software defined radio. In this Paper, we study the regeneration of I and Q signals for the SDR based direct conversion receiver, so that we can handle a wide bandwidth and maintain maximal flexibility in system utilization. After modeling the basic system considering the real wireless communication environment, and studying the impact of imperfect phase imbalance on the performance of a direct conversion receiver, we propose a suboptimal I and Q signal regeneration algorithm for the system. The proposed algerian regenerates I and Q signals using a real time early-late compensator which effectively estimates phase imbalances and gives feedback in a directreceiver. The proposed algorithm is shown to mitigate the impact of AWGN and improves performance especially at low SNR channel condition. According to the computer simulation, the BER performance of the proposed system is at least about 4 dB better than conventional systems under $45{\~}55$ degrees random phase errors.

• Clean Technology
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• v.23 no.3
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• pp.223-236
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• 2017

As the use of waste and biomass increases in a power generation boiler, high temperature corrosion (HTC) problems of boiler heat exchangers are becoming very important. Chlorine of the low-rank fuels is mainly responsible for the HTC issues, which typically occur in the surface of high temperature heat exchanger like a superheater or reheater. In order to mitigate the problem, various approaches have been proposed in terms of design modification, material improvement, fuel pre-treatment and additive utilization. In this study, the current state of research and development focused on the additive method was investigated.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.148-167
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• 1994

The gap of the quality of life and living environment between urban and rural area have been widened since the industrialization and urbanization oriented five year economic development plans started in 1963. To mitigate the gaps, Korean government had commenced the cultural(collective) village development projects, as a pilot cases such as Gyeryong and Ucheon projects from 1991. This paper contains first the concepts of cultural village, types of village formation, types of village development, allocation problems of housing sites, procurement of project costs and other problems experienced during constuction of the projects. The main policy guidelines for the successful development of cultural villages are as follows: 1. Cultural village development should be carried out in coincide with the present status of farm household incomes. 2. The countermeasures should be consistant with the general objective of the cultural village development institutionally. 3. Propaganda of the cultural village development in rural area is prerequisite to success the projects. 4. Favourable terms and conditions of credit loans as loan amount of 30 million won with interest rate of 3% per annum and 25 years repayment period including 5 years grace period should be given by the Government. 5. Special benefits in the tax system should be given to rural peoples in the cultural villages. 6. The cultural village development should be classified into two groups as the cultural village development in rurban area and the cultural village development in rural area.

• Journal of the Korea Society for Simulation
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• v.17 no.3
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• pp.27-34
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• 2008

Wireless sensor networks are comprised of sensor nodes with resource-constrained hardware. Nodes in the sensor network without adequate protection may be compromised by adversaries. Such compromised nodes are vulnerable to the attacks like false reports injection attacks and false data injection attacks on legitimate reports. In false report injection attacks, an adversary injects false report into the network with the goal of deceiving the sink or the depletion of the finite amount of energy in a battery powered network. In false data injection attacks on legitimate reports, the attacker may inject a false data for every legitimate report. To address such attacks, the probabilistic voting-based filtering scheme (PVFS) has been proposed by Li and Wu. However, each cluster head in PVFS needs additional transmission device. Therefore, this paper proposes a fuzzy logic-based false report detection method (FRD) to mitigate the threat of these attacks. FRD employs the statistical en-route filtering scheme as a basis and improves upon it. We demonstrate that FRD is efficient with respect to the security it provides, and allows a tradeoff between security and energy consumption, as shown in the simulation.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.727-734
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• 2012

A new advanced safety feature of DVI+ (Direct Vessel Injection Plus) for the APR+ (Advanced Power Reactor Plus), to mitigate the ECC (Emergency Core Cooling) bypass fraction and to prevent switching an ECC outlet to a break flow inlet during a DVI line break, is presented for an advanced DVI system. In the current DVI system, the ECC water injected into the downcomer is easily shifted to the broken cold leg by a high steam cross flow which comes from the intact cold legs during the late reflood phase of a LBLOCA (Large Break Loss Of Coolant Accident)For the new DVI+ system, an ECBD (Emergency Core Barrel Duct) is installed on the outside of a core barrel cylinder. The ECBD has a gap (From the core barrel wall to the ECBD inner wall to the radial direction) of 3/25~7/25 of the downcomer annulus gap. The DVI nozzle and the ECBD are only connected by the ECC water jet, which is called a hydrodynamic water bridge, during the ECC injection period. Otherwise these two components are disconnected from each other without any pipes inside the downcomer. The ECBD is an ECC downward isolation flow sub-channel which protects the ECC water from the high speed steam crossflow in the downcomer annulus during a LOCA event. The injected ECC water flows downward into the lower downcomer through the ECBD without a strong entrainment to a steam cross flow. The outer downcomer annulus of the ECBD is the major steam flow zone coming from the intact cold leg during a LBLOCA. During a DVI line break, the separated DVI nozzle and ECBD have the effect of preventing the level of the cooling water from being lowered in the downcomer due to an inlet-outlet reverse phenomenon at the lowest position of the outlet of the ECBD.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.4
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• pp.241-247
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• 2010

Corrosion of steel embedded in concrete is one of the foremost factors that affect the durability of concrete structures in marine environments. This paper presents an application technique of anode-ladder-system to evaluate corrosion behaviours of marine concrete structure. In order to investigate the behaviours quantitatively, the measurement of potential and current was performed on the concrete elements subjected to the penetration and diffusion of chloride ions. The main variable was the heights from seawater level; namely 3.7, 6.0 and 8.2 m. As a result of the monitoring, it was found that the corrosion characteristics differently behaved with the increasing height. Additionally, through migration test, the relationship between compressive strength of concrete and diffusivity of chloride ions was observed. It is suggested, ultimately, that in order to reduce or mitigate steel corrosion, both appropriate concrete cover depth and high-quality of concrete in early ages should be done.

• Korean System Dynamics Review
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• v.15 no.4
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• pp.5-28
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• 2014

Derivatives can be easily bought by those companies that need to hedge foreign currency debt or foreign currency assets through the financial market, considering their exchange rate exposure from international trade. The derivatives market has been growing rapidly due to the needs for investment and hedging. To manage foreign exchange risk, companies hedge risks through financial derivatives. According to our study, hedging is an effective way to mitigate the impact of exposure to exchange risk, as long as companies are only hedging underlying assets. Yet, covetous attitude toward the profit from derivatives and unexpected changes in exchange rate can cause problems for companies. This study analyzed the structural risks of derivatives with analysis of system dynamics. In particular, many companies suffered substantial loss due to KIKO during the economic crisis. We explained the problem therein through dynamic analysis. In addition, we revealed the structural problem that could cause a sudden spike in losses through simulations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.2014-2034
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• 2015

This paper focuses on solving co-channel interference (CCI) issues arising in the open subscriber group (OSG) mode of heterogeneous networks (HetNets). Considering a general framework consisting of arbitrary number of picocells within a macro cell, where the inter-user interference (IUI) is the main CCI to macro user equipments (UEs), while the the inter-cell interference (ICI) is the major CCI to pico UEs. In this paper, three IA based transceiver design schemes are proposed. For macro cell, we uniformly use block diagonalization (BD) scheme to eliminate the IUI. And for picocells, three IA schemes are proposed to mitigate the ICI. The first scheme, named as zero forcing IA (ZF-IA) scheme, aligns the inter picocell interference onto an arbitrary sub-space of the cross-tier interference using ZF scheme. Considering the channel state information (CSI) of the desired channel of pico UEs, the second scheme, named as optimal desired sub-channel selected IA (ODC-IA) scheme, aligns the inter picocell interference onto a certain sub-space of the cross-tier interference, which guarantees the largest channel gain of the desired signal of pico UEs. The third IA scheme, named as maximum cross-tier interference selected IA (MI-IA) scheme, is designed for the system with less receive antennas. The inter picocell interference is aligned onto the space of the strongest cross-tier interference and only the interference on this space is nullified. The complexity analysis and simulations show that the proposed transceiver design schemes outperform the existing IA schemes in the OSG mode of HetNets, and the MI-IA scheme reduces the requirement of the receive antennas number with lower complexity.