• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1025-1033
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• 2011

This paper presents a realization of a peer-to-peer communication system for a UAV navigational monitoring using a commercial HSDPA(High Speed Download Packet Access) mobile communication device. The realized system consists of a communication server, an air data terminal and multiple ground monitoring devices, where the server transfers navigational data from a UAV to multiple monitoring devices in real-time with commercial HSDPA modem. Through ground and flight tests, data were obtained to observe the realized system. Test results show that, depending on communicational environment, about 300msec delay, congestion and packet-loss between air data terminal and ground monitoring devices. Nevertheless, through high-speed long range test on a ground vehicle and altitude test with a UAV flight, the feasibility of a UAV navigational monitoring system was observed.

• KSBB Journal
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• v.24 no.1
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• pp.47-52
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• 2009

A pilot-plant biofilter (1750 mm W ${\times}$ 2750 mm L ${\times}$ 2000 mm H) packed with polyurethane foam (20 mm W ${\times}$ 20 mm L ${\times}$ 20 mm H) was installed in an fine chemical plant emitting gas streams containing ethyl alcohol, ethyl acetate, and dichloromethane. The biofilter was successfully operated for 30 days under highly fluctuating incoming concentrations (maximum 3500 ppm) at a residence time of 36 and 60 sec. Both ethyl alcohol and ethyl acetate were removed more than 95%, but dichloromethane removal was less than 50%. Malodor was also removed more than 90% from 17 days after start up.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.7
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• pp.731-738
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• 2012

In this study, the evaluation of the aerodynamic characteristics of the NREL Phase VI Rotor System has been performed, for the 7 m/s upwind case using commercial FEA and CFD tools which are ANSYS Mechanical 12.1 and CFX 12.1. The initial operating conditions of the rotor blade include a $3^{\circ}$ tip pitch angle. A numerical simulation was carried out on only the rotor parts, excluding the tower structure based on the equivalent stiffness model, to consider the aeroelastic effect for the numerical simulation using the loosely coupled 2-way fluid-structure interaction method. The blade root bending moment was monitored in real time to obtain reasonable results. To verify the analysis results, the numerical simulation results were compared with the measurements in the form of the root bending moment and the pressure distributions of the NREL/NASA Ames wind tunnel test.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.108-115
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• 2009

In metal forming technologies, the stamping process is one of the significant manufacturing processes to produce sheet metal components. It is important to design stamping process which can produce sound products without defect such as fracture and wrinkle. The objective of this study is to propose the feasible formability diagram which denotes the safe region without fracture and wrinkle for effective design of stamping process. To determine the feasible formability diagram, FE-analyses were firstly performed for the combinations of process parameters and then the characteristic values for fracture and wrinkle were estimated from the results of FE-analyses based on forming limit diagram. The characteristic values were extended through training of the artificial neural network. The feasible formability diagram was finally determined for various combinations of process parameters. The stamping process of turret suspension to support suspension module was taken as an example to verify the effectiveness of feasible formability diagram. The results of FE-analyses for process conditions within fracture and wrinkle as well as safe regions were in good agreement with experimental ones.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.252-257
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• 1996

La structure syllabique est un facteur important dan la prononciation d'une langue. Dans cette these, on a essaye de montrer que les caracteristiques de la syllabe varie d'une langue a une autre, et que les regles qui regissent la syllabe dan la langue maternelle a le dessue et done fait appliquer ses regles a la langue etrangere. Premierement, l'accentuation du coreen depend de la structure syllabique (qu'elle soit consonne-voyelle(CV) ou consonne-voyelle-consonne(CVC) et de la longueur de la voyelle. Ce qui fait que bien que le francais soit oxyton, et que la longueur et la qualite de la voyelle dependent de la structure syllabique, le francais, le francais parle par les coreens suit les regles du coreen. Autre caracteristique est que le coreen n'admet pas de suite de consonnes avant et apres la voyelle centrale comme dans "premier"[$pr{\partial}mje$] "autre"[o:tR]. D'ou l'insertion de voyelle superflue comme [${\varpi},{\;}{\wedge},{\;}{\partial}$]. Troisiemement, il existe une difference dans la coupe de la chaine parlee: en coreen la coupe ecrite(le blanc) egale a peu pres a la coupe orale(la pause) alors qu'en francais, c'est en groupe de mots que se fait la coupe. A l'interieur du groupe, les mots sont lies entre eux, soity par liaison, soit par enchainement. On peut remarquer donc une nette influence du coreen, ou la regle est de prononcer correctement par unites ecrites (equivalent des mots en francais) : la chaine parlee devient saccadee, avec un accent sur tous les mots, et des coups de glotte entre les mots, et l'une des voyelles [${\varpi},{\;}{\wedge},{\;}{\partial}$] inseree entre un mot se terminant par une consonne suivi d'un mot qui commence par une consonne.

• Korean Journal of Childcare and Education
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• v.8 no.4
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• pp.231-250
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• 2012

The purpose of this study was to inquire into the formation and alteration of child care support policy and the actual of community based child care support policy in Japan in order to draw implications for child care policy in Korea. For the purpose of this study, the research contents are as follows. First, inquire into the formation and alteration of child care support policy. Second, inquire into the actual community based child care support policy. The major literatures reviewed were 'Child Rearing Visions' and 'Child Rearing New System'(The Cabinet Office, 2010) in Japan. For child care policy in Korea, two implications were drawn from community based child care support policy in Japan. First, it is necessary to establish macroscopic, comprehensive child care policy. And, the policy has to consider local finance and conditions of the community. Second, the child care budget based on liaison government and community should be expanded. Also, it has to provide child care support service through a community network.

• Convergence Security Journal
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• v.17 no.4
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• pp.79-87
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• 2017

The U.S. security regulation is under the influence of each state's law; however, they are mostly similar. Among many states which has the longest history of security regulation in the U.S., state of New York has been shown security regulation for a long time. The state of New York has been emphasized the importance of security significantly because it is economically, culturally, and internationally important place at the same time. New York's state law of security business includes: 1. private investigators and bail enforcement agents and watch, guard or patrol agencies license law. 2. Security guard act of 1992~,3. Title 19 New York State's code of rules and regulation (NYCRR). The law of New York City's private security could inspire Korean private security law in many ways. First, administration of professional law and variety of licensure could be an inspiration to the Korean security services. Second, there are intimate partnership between police and private security in the U.S. New York police's private security partnership has been started since 1986 by Area Police/Private Security Liaison (APPL program) and there are about 1,300 of security companies participating. This program provides not only the simple partnership but also giving essential information for promoting public safety.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.1-7
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• 2012

In this research, a single-axis attitude control test bed is developed, and simulation and tests experiments are performed, as a preliminary research of a quad-rotor aerial vehicle development. A single-axis test bed with seesaw configuration is manufactured using two motors and propellers, and the aerodynamic parameters are derived by thrust tests. The response of the system is estimated with Matlab/Simulink, and experiments are performed with attitude control computer and an attitude sensor onboard the test bed. Comparing the results of simulated and tested data, factors of steady-state errors during experiments are found, and performances of used attitude control algorithm and the control computer were verified. In these process, essential preliminary data for attitude control of a quad-rotor unmanned aerial vehicle were acquired.

• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.181-188
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• 2011

A small UAVs(Unmaned Aerial Vehicles) have limited by the payload capacity which requires miniaturization of a navigation system. In this paper, the performance of the lightweight and small sized AHRS(Attitude Heading Reference System), which is self-developed, is evaluated at low acceleration environment. The designed AHRS adopts the commercial low-cost MEMS sensors. A quaternion-based attitude calculation method, which eliminates singularity with relatively simple algebra, is used. In an attitude correction algorithm, the Kalman filter is used with accelerometers and magnetometers combined. The fabricated AHRS is also evaluated with reference to a COTS(Commercial Off-The-Shelf) AHRS which reports a number of successful applications to a small UAVs. The test results show that the measurements from the fabricated AHRS provide proper attitude output data with acceptable amount of differences(horizontal axis 0.5$^{\circ}$, vertical axis 1.5$^{\circ}$) in test environment.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E4
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• pp.203-213
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• 2002

Receptor modeling is one of statistical methods to achieve reasonable air pollution strategies. In order to maintain and manage ambient air quality, it is necessary to identify sources and to apportion its sources for ambient particulate matters. The main purpose of the study was to survey seasonal trends of inorganic elements in the coarse and fine particles. Second, this study has attempted emission sources qualitatively by a receptor method, the PMF mo-del. After that. both PMF (positive matrix factorization) model and TTFA (target transformation factor analysis) model were applied to compare and to estimate mass contribution of coarse and fine particle sources at the receptor. A total of 138 sets of samples was collected from 1989 to 1996 by a low volume cascade impactor with 9 size fraction stages at Kyung Hee University in Korea. Sixteen chemical species (Si, Ca, Fe, K, Pb, Na, Zn, Mg, Ba, Ni, V, Mn, Cr, Br, Cu. Co) were characterized by XRF. The study result showed that the weighted arithmetic mean of coarse and fine particles were 51.3 and 54.4 $\mu\textrm{g}$/㎥, respectively. Contribution of both particle fractions were esti-mated using TTFA and PMF models. The number of estimated sources was seven according to TTFA model and 8 according to PMF model. Comparison of TTFA and PMF revealed that both methodologies exhibited similar trends in their contribution pattern. However, large differences between contributions were observed in some sour-ces. The results of this study may help to suggest control strategies in local countries where known source profiles do not exist.