• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1521_1522
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• 2009

Chemotaxis is the directed movement of cells in gradients of signaling molecules, an essential biological process that underlies morhpogenesis during development, and the recruitment of immune cells to sites of infection. Especially, bacterial chemotaxis has utilized as an important prelude to study metabolism, prey-predator relationship, symbiosis, other ecological interactions in microbial communities. Recently, novel analytical formats integrated with microfluidics were introduced to investigate the chemotaxis of the cells with the precise control of chemical gradient and small volume of cells. In this study, we present a method to detect bacterial chemotaxis by direct fluidic contacting. The developed fluidic-handling method is driven by capillary force, hydrophobic barrier and a cohesion force between fluids. We have investigated the chemotactic response of E Coli. and Pseudomonas aeruginosa to three kinds of chemoeffectors such as HEPES buffer, peptone and chloroform.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2001.10a
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• pp.248-265
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• 2001

Recently, agriculture in Korea is seriously depressed by economic globalization and trade liberalization because of low competitive power. Organic farming, which is favorable for small scale agriculture, is expected to be one of alternatives to boost agricultural activities in Korea. Organic agriculture requires systemic developments of new technologies considering the complex biological interaction within the system in connection with high quality and safety standard. The National Institute of Agricultural Science & Technology(NIAST) has been worked on the series of organic farming technologies, including bio-pesticides, pheromone, natural enemies as well as the testings of materials used in organic farming. NIAST will concentrate on the technological development for compromising to the conflict between commodity-oriented and ecological harmony. Research on systemic land and water use, management of plant nutrition, pest and disease control, post-harvest would also be important targets. Integrated efforts among researchers, professors, administrators, farmers, private sectors, and extension workers are substantial for fast technology development and its dissemination. Development and use of these technologies will homely enlighten the Korean organic farming although it may require quite a time and endeavor.

• Journal of Biomedical Engineering Research
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• v.18 no.1
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• pp.51-64
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• 1997

A dynamic model of the Korean total artificial heart(TAH) which contains a brushless DC motor, all of mechanical components, the pump system with integrated variable volume space(WS) and the circulatory system model including the bronchial circulation were established Two different sets of seven differential equations were separately derived for the left and right systolic period of the Korean TAH operation. Throughout the computer simulation, a full-state fEedback optimal controller that minimizes the power consumption of the Korean TAH and drives the end stage velocity of the energy converter to zero was developed based upon the optimal control theory. Robustness of the controller were also analyzed with the dynamic model of the Korean TAH.

• 보존과학연구
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• s.21
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• pp.5-55
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• 2000

The cultural properties are damaged by various causes according to the characteristics of material, the condition of preservation, and the period of time. Especially, biodeterioration makes lots of damages in organic properties than inorganic ones. The damages of wooden cultural properties by insects usually are caused by the three orders; Isoptera, Coleoptera, and Hymenoptera. As the result of investigation on the state of 141 buildings of wooden cultural properties in 1999, some of them were damaged by many kinds off actors; wasp, powder post beetle, cigarette beetle, termite, decay, and physical cracking. And it was found that the patterns of damages were related to species-specific habits of insects. There are several methods of pest control for the prevention of wooden cultural properties from damages caused by insects. Those are as follows; physical control, chemical control, biological control, and integrated pest management. When insects and fungi were detected at the wooden buildings, the fumigation is best treatment to stop biodeterioration. And then, wood materials also need to be treated with insecticidal and antiseptic chemicals to avoid a reinfestation, because the fumigant is volatile. The six commercial chemicals which are applied to the insecticidal and antiseptic treatment of wooden cultural properties were purchased to test their abilities. According to the comparative results of efficacy of them in laboratory, chemical D showed excellent efficacy in all items, including antiseptic and termiticidal items. The goal of these pest controls is to protect wooden buildings from insects and microorganisms. The most effective method used currently is chemical control(fumigation, insecticidal and anticeptic chemical treatment), but it has to be treated periodically to control pest effectively. Recently environmentally-friendly control methods such as bait system or biological treatments are replacing traditional barrier treatments using large amounts of chemicals. Especially, termite is a social insect which makes a colony. Although a building with fumigation treatment is safe for a while, once attacked building has a risk of damage by reinfestation of termite. Therefore, to control termites from damaged building, the entire colony including reproductives(queen and king) and larvae around buildings must beeliminated. Bait system can be used as a preventive measure in early detection of them through termites colony monitoring and baiting. It would be the most effective for termite control if bait system would be used together with the chemical controls.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.3
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• pp.331-336
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• 2020

Consequence management (CM) remains a relatively unknown or underdeveloped concept in Republic of Korea. This study was conducted as a literature study, perceiving that good CM is critical when viewed under contemporary disaster types and comprehensive security. From the perspectives of integrated disaster control and comprehensive security, it would be necessary for South Korea to implement the concept of CM widely used in countries with advanced disaster control. In particular, this study verifies the need of the military to respond actively to Chemical, Biological, Radiation, Nuclear, and high yield Explosives (CBRNE) situations. A plan for the development of the CM organization of the ROK Armed Forces is proposed by using the CBRNE-CM response organization of the United States as a model.

• The Korean Journal of Soil Zoology
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• v.9 no.1_2
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• pp.24-28
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• 2004

Predaceous phytoseiid mites can be important components in integrated mite management program including bio-logical control of spider mites. While conducting population study of prey-predator system in pear orchards, 6 predaceous phytoseiids were found. Amblyseius womersleyi, A. eharai, A. kokufuensi and A. finlandicus were mostly found from tree canopy. While A. rademacheri was restricted in ground vegetation, A. makuwa was equally distributed in ground vegetation and tree trunk. Some ecological information for each species was reviewed. Strate-gies for their potential utility in pest management program and future study area were discussed.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.55-58
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• 1997

In this paper we reviewed and stated the present state of our team's research of the moving-actuator type total artificial heart (MA-TAH). Especially, this paper showed new direction of researches. The integrated research of battery, telemetry, TET is required. And the real-time supervisory of the state of hemodynamic variables and MA-TAH is also needed. These requirement made us to think the supervisory control system (SCS). As functional abilities of the SCS require very high computational cost, the digital signal processor is an appropriate choice for our need.

• Journal of Biomedical Engineering Research
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• v.44 no.2
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• pp.99-108
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• 2023

According to the COVID-19, development of various medical software based on IoT(Internet of Things) was accelerated. Especially, interest in a central software system that can remotely monitor and control ventilators is increasing to solve problems related to the continuous increase in severe COVID-19 patients. Since medical device software is closely related to human life, this study aims to develop central monitoring system that can remotely monitor and control multiple ventilators in compliance with medical device software development standards and to verify performance of system. In addition, to ensure the safety and reliability of this central monitoring system, this study also specifies risk management requirements that can identify hazardous situations and evaluate potential hazards and confirms the implementation of cybersecurity to protect against potential cyber threats, which can have serious consequences for patient safety. As a result, we obtained medical device software manufacturing certificates from MFDS(Ministry of Food and Drug Safety) through technical documents about performance verification, risk management and cybersecurity application.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.265-271
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• 2021

Intertidal mud crab (Macrophthalmus japonicus) is an organism with a hard chitinous exoskeleton and has function for an osmotic control in response to the salinity gradient of seawater. Crustacean exoskeletons change in their natural state in response to environmental factors, such as changes in the pH and water temperature, and the presence of pollutant substances and pathogen infection. In this study, the ecotoxicological effects of irgarol exposure and heavy metal distribution were presented by analyzing the surface roughness of the crab exoskeleton. The exoskeleton surface roughness and variation reduced in M. japonicus exposed to irgarol. In addition, it was confirmed that the surface roughness and variation were changed in the field M. japonicus crab according to the distribution of toxic heavy metals(Cd, Pb, Hg) in marine sediments. This change in the surface roughness of the exoskeleton represents a new end-point of the biological response of the crab according to external environmental stressors. This suggests that it may affect the functional aspects of exoskeleton protection, support, and transport. This approach can be utilized as a useful method for monitoring the aquatic environment as an integrated technology of mechanical engineering and biology.

• Current Optics and Photonics
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• v.1 no.1
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• pp.51-59
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• 2017

In addition to its typical use for skin rejuvenation, fractional laser irradiation of early cancerous lesions may reduce the risk of tumor development as a byproduct of wound healing in the stroma after the controlled injury. While fractional ablative lasers are commonly used for cosmetic/aesthetic purposes (e.g., photorejuvenation, hair removal, and scar reduction), we propose a novel use of such laser treatments as a stromal treatment to delay tumorigenesis and suppress carcinogenesis. In this study, we found that non-ablative fractional laser (NAFL) irradiation may have a possible suppressive effect on early tumor growth in syngeneic mouse tumor models. We included two syngeneic mouse tumor models in irradiation groups and control groups. In the irradiation group, a thulium fiber based NAFL at 1927 nm was used to irradiate the skin area including the tumor injection region with 70 mJ/spot, while no laser irradiation was applied to the control group. Numerical simulation with the same experimental condition showed that thermal damage was confined only to the irradiation spots, sparing the adjacent tissue area. The irradiation groups of both tumor models showed smaller tumor volumes than the control group at an early tumor growth stage. We also detected elevated inflammatory cytokine levels a day after the NAFL irradiation. NAFL treatment of the stromal tissue could potentially be an alternative anticancer therapeutic modality for early tumorigenesis in a minimally invasive manner.