• 한국인터넷방송통신학회논문지
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• 제21권1호
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• pp.61-68
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• 2021

과거의 레이다는 임무 특성에 맞게 사격통제레이다, 탐지레이다, 추적레이다, 영상획득 레이다 등으로 구분되어 운영해왔다. 하지만 다기능 레이다는 표적 탐지, 추적, 피아식별, 재머 탐지 및 대응 등 단일 시스템 안에서 다양한 임무를 수행한다. 때문에 한정된 자원으로 다기능 레이다를 운용하기 위한 효율적인 자원관리는 필수적이다. 특히 탐지된 표적의 추적을 위한 표적 위협도와 이를 바탕으로 추적주기를 선정하는 방법은 중요한 이슈다. 위협표적을 집중으로 추적하다보면 다른 영역에서 탐지된 표적을 효율적으로 관리할 수 없고 탐지에 집중을 하면 추적성능이 저하될 수 있다. 때문에 효과적인 스케줄링이 필수적이다. 본 논문에서는 다기능 레이다 스케줄링 방안인 TaP(Time and Priority)알고리즘과 이를 구성하기 위한 소프트웨어적 설계 방법에 대해 제안한다.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.39-45
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• 1995

The plywoods commonly used as decorative interior materials for the construction are inflammable and so it is a causative factor for making fire accidents, resulting in the destruction of human life and personal properties. Indeed, it is, therefore, required to produce fire-retardant plywoods. In this study, a special grade of defect-free, Kapur plywood was used. Specimens were cut into 3- by 20cm dimensions from 120- by 240- by 0.33-cm panels(thin panel) or 120- by 240- by 0.5-cm panels(thick panel). Some specimens were treated with diammonium phosphate(DAP), but some were not treated with diammonium phosphate to use as control panels. Chemical absorption, drying curves, drying rates and dynamic Young's modulus were investigated. The results were summaries as follows; 1. The specimens were soaked into 19% diammonium phosphate solution by a full cell pressure process and the diammonium phosphate retained in the thin and thick plywoods was 1.409kg/$(30cm)^3$, 1.487kg/$(30cm)^3$, respectively. 2. Diammonium phosphate-treated plywoods were redried with press-drying process at one of either condition dried on the platen($115^{\circ}C$) for a period of time or dried on the platen($50^{\circ}C$) for 3 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. or dried on the platen($60^{\circ}C$) for 2 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. The drying rate of treated thin specimens dried at $60^{\circ}C$ plus $30^{\circ}C$ and $115^{\circ}C$ only was found to be 0.04 %/min. and 8.53 %/min. Similarly, the drying rate of treated thick specimens were 0.03 %/min. and 6.77 %/min. respectively. 3. It was evident that highly-significantly different drying rate of treated plywoods was observed between plywood thicknesses and platen temperatures and the rate was increased by elevating the platen temperature up to $115^{\circ}C$. Based on the two-way variance analysis, highly significant drying rate was observed from the interaction between plywood thicknesses and platen temperatures. 4. After redrying, the specimens were weighed and reconditioned to a constant weight in a facility maintained temperature ($20^{\circ}C$) and relative humidity(65%) prior to test dynamic Young's modulus. The test revealed that the thin specimens dried at the platen temperature of $50^{\circ}C$, $60^{\circ}C$, $115^{\circ}C$ and untreated specimens showed 1.070E+09 dyne/$cm^2$, 1.156E+09 dyne/$cm^2$, 1.243E+09 dyne/$cm^2$, and 1.052E+09 dyne/$cm^2$, respectively. Likewise, the thick specimens revealed 5.647E+09 dyne/$cm^2$ 5.670E+09 dyne/$cm^2$, 6.395E+09 dyne/$cm^2$ and 5.415E+09 dyne/$cm^2$, respectively. 5. It was evident that significantly different dynamic Young's modulus was observed between the plywood thickness and the platen temperature, but not in the two-way interaction between the plywood thickness${\times}$the platen temperature.

• Journal of Ginseng Research
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• 제43권4호
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• pp.676-683
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• 2019

Background: Korean Red Ginseng (KRG) is widely used for strengthening the immune system and fighting fatigue, especially in people with deficiency syndrome. However, there is concern that the long-term application or a high dose of KRG can cause "fireness" (上火 in Chinese) because of its "dryness" (燥性 in Chinese). The aim of this study was to assess the safety and efficacy of a 4-week treatment with KRG in participants with deficiency syndrome. Methods: This was a 4-week, randomized, double-blind, placebo-controlled clinical trial. A total of 180 Chinese participants were randomly allocated to three groups: placebo control group, participants were given a placebo, 3.6 g/d; KRG 1.8 g and 3.6 g groups. The primary outcomes were the changes in fireness and safety evaluation (adverse events, laboratory tests, and electrocardiogram). The secondary outcomes were the efficacy of KRG on fatigue, which include the following: traditional Chinese medicine (TCM) symptom scale and fatigue self-assessment scale. Results: Of the 180 patients, 174 completed the full study. After 4 weeks of KRG treatment, the Fire-heat symptoms score including Excess fire-heat score and Deficient fire-heat score showed no significant change as compared with placebo treatment, and no clinically significant changes in any safety parameter were observed. Based on the TCM syndrome score and fatigue self-assessment score, TCM symptoms and fatigue were greatly improved after treatment with KRG, which showed a dose- and time-dependent effect. The total effective rate was also significantly increased in the KRG groups. Conclusion: Our study revealed that KRG has a potent antifatigue effect without significant adverse effects in people with deficiency syndrome. Although a larger sample size and longer treatment may be required for a more definite conclusion, this clinical trial is the first to disprove the common conception of "fireness" related to KRG.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.901-920
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• 2015

Wireless Sensor Networks (WSNs) are widely used in geographically isolated applications like military border area monitoring, battle field surveillance, forest fire detection systems, etc. Uninterrupted power supply is not possible in isolated locations and hence sensor nodes live on their own battery power. Localization of sensor nodes in isolated locations is important to identify the location of event for further actions. Existing localization algorithms consume more energy at sensor nodes for computation and communication thereby reduce the lifetime of entire WSNs. Existing approaches also suffer with less localization coverage and localization accuracy. The objective of the proposed work is to increase the lifetime of WSNs while increasing the localization coverage and localization accuracy. A novel intelligent unmanned aerial vehicle anchor node (IUAN) is proposed to reduce the communication cost at sensor nodes during localization. Further, the localization computation cost is reduced at each sensor node by the proposed intelligent arc selection (IAS) algorithm. IUANs construct the location-distance messages (LDMs) for sensor nodes deployed in isolated locations and reach the Control Station (CS). Further, the CS aggregates the LDMs from different IUANs and computes the position of sensor nodes using IAS algorithm. The life time of WSN is analyzed in this paper to prove the efficiency of the proposed localization approach. The proposed localization approach considerably extends the lifetime of WSNs, localization coverage and localization accuracy in isolated environments.

• 항공우주기술
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• 제9권2호
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• pp.105-115
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• 2010

본 논문에서는 소형항공기의 종축 및 횡방향축 동안정성 비행시험을 수행하고 그 결과를 분석 정리하였다. 대상 항공기는 한국항공우주연구원에서 개발한 4인승 선미익형 항공기인 반디 실용화 1호기이며, 탑재 센서 및 실시간 텔레메트리시스템을 통해 비행시험 데이터를 확보하였다. 대상 항공기의 동안정성 비행시험은 대상 항공기 운동모델의 공력 미계수를 추정하여 고유주파수 및 댐핑 등의 비행성을 판별하여 동안정성을 분석할 목적으로 수행되며, 본 비행시험에서는 chirp, 3211 및 doublet 조종입력을 사용하여 비행데이터를 확보한 후 최대공산 추정기법 (MMLE)을 적용하여 공력 미계수를 추정하였다.

• 대한산업공학회지
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• 제37권2호
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• pp.96-104
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• 2011

Modeling and simulation of human-involved complex systems pose challenges to representing human decision makings into logical systems because of the nondeterministic and dynamic nature of human behaviors. In modeling perspectives, human's activities in systems can increase uncertainty and complexity, because he or she can potentially access all other resources within the system and change the system states. To address all of these human involvements in the system, this research suggests applying the Finite State Automata (FSA)-based formal modeling of human-involved systems that incorporates the ecological concept of affordances to an evacuation simulation, so that human behavioral patterns under urgent and dynamic emergency situations can be considered in the real-time simulation. The proposed simulation methodologies were interpreted using the warehouse fire evacuation simulation to clarify the applicability of the proposed methodology. This research is expected to merge system engineering technologies and human factors, and come out to the new predictive modeling methodology for disaster simulations. This research can be applied to a variety of applications such as building layout designs and building access control systems for emergency situations.

• 시스템엔지니어링학술지
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• 제16권1호
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• pp.68-77
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• 2020

The shipbuilding and offshore industry is a large and complex assembly industry, which causes many safety accidents. The major accidents in the shipbuilding and offshore industry workplaces are stenosis, falling objects, dust, fire, explosions, and gas poisoning. The accident by worker in this industry mainly has three factors: frequent movement, narrow work space, and increased use of subcontractors. To control these factors, it is necessary to monitor the worker's location and work status. In this paper, a worker location monitoring system using inaudible sound wave was designd that can be used in environments with many metal barriers. The process included deriving stakeholder requirements, transforming to system requirements, designing system architecture, and developing prototype. The prototype was validated by third-party testing agency. As a result, it satisfied the designed performance and verified its feasibility.

• Journal of Electrochemical Science and Technology
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• 제11권4호
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• pp.346-351
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• 2020

The removal characteristics of copper (Cu) from electrochemical surface by voltage-activated reaction were reviewed to assess the applicability of electrochemical-mechanical polishing (ECMP) process in three types of electrolytes, such as HNO₃, KNO₃ and NaNO₃. Electrochemical surface conditions such as active, passive, transient and trans-passive states were monitored from its current-voltage (I-V) characteristic curves obtained by linear sweep voltammetry (LSV) method. In addition, the oxidation and reduction process of the Cu surface by repetitive input of positive and negative voltages were evaluated from the I-V curve obtained using the cyclic voltammetry (CV) method. Finally, the X-ray diffraction (XRD) patterns and energy dispersive spectroscopy (EDS) analyses were used to observe the structural surface states of a Cu electrode. The electrochemical analyses proposed in this study will help to accurately control the material removal rate (MRR) from the actual ECMP process because they are a good methodology for predicting optimal electrochemical process parameters such as current density, operating voltage, and operating time before performing the ECMP process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
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• pp.136-139
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• 2003

Thermal imaging system is electro-optical imaging device which can make visible the difference of infrared energy naturally emitted by objects. It is acquire the same images at any time of the day or night. There it has been readily available to the night observation such as fire control systems. In this study, we are manufacturing thermal image Al flat mirror. The surface roughness 3.539nm Ra and power 0.382 fringe(at 632.8nm), irregularity 0.835 fringe(at 632.8nm) for form waviness of thermal image Al flat mirror are very satisfied. The results will be reflected for development of the ultra precision application. And a brief review of Ultra-precision system in the field of Ultra-precision at Korea photonics technology institute (KOPTI) is present in this paper.

• 산업경영시스템학회지
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• 제33권2호
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• pp.23-32
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• 2010

In this paper, we proposed the modified method of Metcalfe's law that is "Modfied law" in evaluating the network power for the measurement of combat effectiveness in C4I system. It is applied to JFOS-K (Joint Fire Operating System-Korea) C4I system that can connect KJCCS (Korea Joint Command and Control System) of Korea armed forces with JADOCS (Joint Automated Deep Operations Coordination System) of U.S. armed forces and achieve sensor to shooter system in real time in JCS (Joint Chiefs of Staff) level. The result of combat effectiveness using Modified law is compared to the one by C2 theory and found that both is similar. This study is meaningful because we improved the description level of reality in calculation of combat effectiveness in C4I system.