• Journal of Institute of Control, Robotics and Systems
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• v.13 no.10
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• pp.1025-1031
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• 2007

GPS is widely used for positioning applications and attitude of a vehicle can be found also with multiple antennas. However, extremely weak signal level prevents GPS from indoor operation. DR with accelerometers and gyros and landmark based localization method used for indoor applications increase complexity and cost. In this paper, a simple but very efficient ultrasound based attitude determination system which determines both position and attitude in WSN is given. The range between transmitter and receivers are measured using the arrival time difference between ultrasound and RF signal. The 3 dimensional positions can be found using more than 3 range measurements. Furthermore, if more than 2 transmitters are used, the attitude can be determined using the baseline vectors obtained by differencing transmitter and receiver positions. The prototype system is implemented to evaluate the performance of the proposed method. In addition, an error analysis shows the relation between the attitude error and basel me length, quality of measurement and orientation of a vehicle. The static and dynamic experiments performed by micro mobile robot shows accurate position with less than 1.5cm error and attitude with less than 1 degree error can be obtained continuously with 20cm baseline. It is expected that these results can be adapted without modification to indoor applications such as home cleaning robot and autonomous wheelchair maneuvering.

• Development and Reproduction
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• v.17 no.3
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• pp.231-240
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• 2013

Olive flounder (Paralichthys olivaceus) is one of the commercial important flatfish species in Korea. The ocular signal transduction pathway is important in newly hatched flounders because it is closely involved in the initial feeding phase thus essential for survival during the juvenile period. However, the study of gene expression during ocular development is incomplete in olive flounder. Therefore we examined the expression analysis of specifically induced genes during the development of the visual system in newly hatched flounders. We searched ocular development-involved gene in the database of expressed sequence tags (ESTs) from olive flounder eye and this gene similar to arrestin with a partial sequence homology. Microscopic observation of retinal formation corresponded with the time of expression of the arrestin gene in the developmental stage. These results suggest that arrestin plays a vital role in the visual signal transduction pathway of the retina during ocular development. The expression of arrestin was strong in the ocular system during the entirety of the development stages. Our findings regarding arrestin have important implications with respect to its biological role and evolution of G-protein coupled receptor (GPCR) signaling in olive flounder. Further studies are required on the GPCR-mediated signaling pathway and to decipher the functional role of arrestin.

• Toxicological Research
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• v.17
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• pp.167-171
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• 2001

The introduction of genetically modified crops has raised concerns regarding safety issues over the insertion of foreign genes into plant genomes using recombinant DNA technology. Since 1991 in Japan, 29 foods and 6 food additives have been evaluated, based on the "Guideline for Safety Assessment", before these foods were marketed. The MHW, however, decided that safety assessment of such foods and food additives should be legally imposed. because soon such foods and food additives are expected to circulate globally and a new system for assessing safety of such foods and food additives at a pre-market stage is necessary, in order to avoid the distribution of any genetically modified foods that have had no safety assessment. The MHW published relevant announcements to amend existing regulations on 1 May 2000. "Standards for safety assessment of seed plant" is established based on a concept of substantial equivalence, and applicable to the products which are regarded as equivalent to the existing products used as foods and food additives. The characterization of the food products entails consideration of the molecular characterization. phenotypic and compositional characteristics, key nutrients and toxicants, and toxicity and allergenicity of the introduced proteins, and if there are indications of unintended effects of the modification, whether further safety testing (animal studies etc.) is needed should be considered. Safety and wholesomeness studies with whole foods should be care fully designed in order to avoid nutritional imbalances causing artifacts and uninterpretable results as was the case of Dr. Pusztaiis report. A case study of genetically modified soybeans (glyphosate-tolerant soybeans) on the immune system of rats and mice is shown. Chemical compositions were also compared with those of the non-GM soybeans. The studies failed to detect any differences in immuno-toxic activity.muno-toxic activity.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.293-298
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• 2011

The combustion and flow-rate control characteristics of fuel-rich gas generator which could be adopted to Ducted Rocket propulsion system are investigated. The gas generator is designed considering the design requirements of propulsion system and solid fuel for fuel-rich combustion is developed then adopted to ground test. The results of combustion test show the necessity of the special analysis tool for estimating the gas generator performance where multi-phase flow of fuel-rich gas exists. During the flow-rate control test, characteristics of gas generator pressure with the angle of valve are analyzed and, method to estimate the pressure of gas generator is suggested using the relation between the valve exit area and discharge coefficient.

• Journal of the Korean Professional Engineers Association
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• v.17 no.3
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• pp.32-49
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• 1984

The East gate station area is 205M long and 24m deep which is located 13 meter in front of cultural treasure east gate. The area to be excavated by blasting is composed of granite rocks from 10M depth to 25M. Surface earth extends to up 10M depth. This job site has in involves heavy traffic congestion such as over 10,000 cars passing in rush hour where clossing No 1 lint of subway running 3 minitues head way. This east gate station construction is to be executed for the provent of the setting down of underground level and blasting vibration effects to cultural treasure east gate. Therefore, the caltural treasure committee approved this execution subject to the following condition. 1. Subway gelogical foundation and measured natural frequency 2. Execution of water tight wall 3. Sellection and test of damping material for wall and under rail 4. Measurement of monitoring system during the execution 5. Measurement of histogram system The above two projects was carried out by Dr. Kwang team in KAIST and prof, Han in Hanyang University under accadamic study contract. In the blasting work, for the pourpose of reduced vibration and low explosion velocity such as CCR, Kovex slurry. The 2nd, used electrical caps shall be delay cap and M/S caps in multi delay. The 3rd, drilling pattern is bench cut in open cut and applied control blasting in tunnelling and also shall drill anti-vibration holes as line drilling.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.178-185
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• 2007

A study is improvement of power and emission in a inline-pump Dr diesel engine by using Dimethyl ether Fuel. Dimethyl ether (DME) is an oxygenated fuel with a cetane number higher than that of diesel oil. It meets the ULEV emission regulation and reduces the smoke to almost zero when used in a diesel engine. But NOx emission is almost same and CO, THC emissions are lower than that of diesel engine. The emissions aren't satisfied the stronger emission regulation in the further. Generally DOC (Diesel Oxidation Catalyst) is used to reduce CO & THC emissions and EGR (Exhaust Gas Recirculation) system is used to reduce NOx emission. Test results showed that the torque and the power with DME were almost same as those of pure diesel oil, but the brake thermal efficiency increased a little. also the BSEC (Brake Specific Energy Consumption) with DME was similar that of diesel. The test results showed that the DOC was the vary effective method to reduce the CO emission in case of Dimethyl Ether Fuel in diesel engine. But, THC emission is showed a little reduction rates. Also EGR system was the very effective method to reduce the NOx emission in case of Dimethyl Ether Fuel in diesel engine.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.187-192
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• 2008

The Intelligent Space(ISpace) provides challenging research fields for surveillance, human-computer interfacing, networked camera conferencing, industrial monitoring or service and training applications. ISpace is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment, it is very important that the system knows the location information to offer the useful services. In order to achieve these goals, we present a method for representing, tracking and human Jollowing by fusing distributed multiple vision systems in ISpace, with application to pedestrian tracking in a crowd. This paper describes appearance based unknown object tracking with the distributed vision system in intelligent space. First, we discuss how object color information is obtained and how the color appearance based model is constructed from this data. Then, we discuss the global color model based on the local color information. The process of learning within global model and the experimental results are also presented.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.237-242
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• 2012

Purpose: The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea. Materials and Methods: One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine. Results: The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 $mGycm^2$ (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 $mGycm^2$ (DAP). Doses at university dental hospitals were lower than those at dental clinics (p<0.05). Doses of digital radiography (DR) type were lower than those of film-based type (p<0.05). Conclusion: We recommend 3.1 mGy (PED), 87.4 $mGycm^2$ (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.06a
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• pp.1-10
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• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control sub-process through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are-white water consistency control which is the most effective way to control retention - charge demand measurement and control which takes care of concentration of the anionic material entering to PM -ash measurements and controls which are deeply related to retention and paper quality This paper presents and concentrates to two of these key controls ; retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloida material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately , and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation , and results of our unique wet end analyzers (retention and charge ) which are at the level of automation solutions as a part of paper machine quality control Especially our newest member of the platform , on-line charge analyzer has reached and set new standards to the on-line charge monitoring.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.478-484
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• 2008

When a mobile node moves, MIPv6 operates an authentication process for the new connection. These kinds of frequent binding update and authentication processes cause much traffic and delay the service. To solve this problem, PMIPv6 provides a network-based mobility protocol in order to lessen the load on a mobile node. However, when it is moved from a domain to a domain or in a domain, there still lies a need fDr a new address, so MIPv6's demerit still exists. In IPsec, too, a new negotiation should be made when it is moved to WAN(Wide Area Network). This causes load to the mobile node. In this paper suggests MBB(Make Before Break) system to eliminate disconnections or delays resulted from the address change or renegotiation for security. When the mobile node receives a CoA address, IPsec negotiation gets operated. Its identity is authenticated by sending the identifier used for the prior negotiation to CN(Correspondent Node) through the BID message suggested. After that, negotiation Bets simplified that disconnections can be eliminated, and in the IPsec negotiation, the load on the mobile node can be lessened as well; moreover, two addresses are used for the communication simultaneously, so the probability of packet loss can be reduced.