• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권9호
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• pp.4271-4294
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• 2018

Communication cost is the most important factor in Wireless Sensor Networks (WSNs), as exchanging control keying messages consumes a large amount of energy from the constituent sensor nodes. Time-based Dynamic Keying and En-Route Filtering (TICK) can reduce the communication costs by utilizing local time values of the en-route nodes to generate one-time dynamic keys that are used to encrypt reports in a manner that further avoids the regular keying or re-keying of messages. Although TICK is more energy efficient, it employs no re-encryption operation strategy that cannot determine whether a healthy report might be considered as malicious if the clock drift between the source node and the forwarding node is too large. Secure SOurce-BAsed Loose Synchronization (SOBAS) employs a selective encryption en-route in which fixed nodes are selected to re-encrypt the data. Therefore, the selection of encryption nodes is non-adaptive, and the dynamic network conditions (i.e., The residual energy of en-route nodes, hop count, and false positive rate) are also not focused in SOBAS. We propose an energy efficient selection of re-encryption nodes based on fuzzy logic. Simulation results indicate that the proposed method achieves better energy conservation at the en-route nodes along the path when compared to TICK and SOBAS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권9호
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• pp.4183-4204
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• 2018

The existing en-route filtering schemes only consider some simple false data injection attacks, which results in lower safety performance. In this paper, we propose an efficient geographical information-based en-route filtering scheme (EGEFS), in which each forwarding node verifies not only the message authentication codes (MACs), but also the report identifier and the legitimacy and authenticity of locations carried in a data report. Thus, EGEFS can defend against not only the simple false data injection attacks and the replay attack, but also the collusion attack with forged locations proposed in this paper. In addition, we propose a new method for electing the center-of-stimulus (CoS) node, which can ensure that only one detecting node will be elected as the CoS node to generate one data report for an event. The simulation results show that, compared to the existing en-route filtering schemes, EGEFS has higher safety performance, because it can resist more types of false data injection attacks, and it also has higher filtering efficiency and lower energy expenditure.

• Advances in nano research
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• 제10권2호
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• pp.191-210
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• 2021

To compare the antifungal effect of two nanomaterials (NMs), nanoparticles of zinc oxide were synthesized by a chemical route and zinc oxide-based nanobiohybrids were obtained using green synthesis in an extract of garlic (Allium sativum). The techniques of X-Ray Diffraction (XRD), Infrared (IR) and Ultraviolet Visible (UV-Vis) absorption spectroscopies and Scanning (SEM) and Transmission Electron Microscopies (TEM) were used to determine the characteristics of the nanomaterials synthesized. The results showed that the samples obtained were of nanometric size (< 100 nm). To compare their antifungal capacity, their effect on Cercospora sp. was evaluated. Test results showed that both nanomaterials had an antifungal capacity. The nanobiohybrids (green route) gave an inhibition of fungal growth of ~72.4% while with the ZnO-NPs (chemical route), inhibition was ~87.1%. Microstructural studies using High Resolution Optical Microscopy (HROM) and ultra-structural analysis using TEM carried out on the treated strains demonstrated the effect of the nanofungicides on the vegetative and reproductive structures, as well as on their cell wall. To account for the antifungal effect presented by ZnO-NPs and ZnO nanobiohybrids on the fungi tested, effects reported in the literature related to the action of nanomaterials on biological entities were considered. Specifically, we discuss the electrical interaction of the ZnO-NPs with the cell membrane and the biomolecules (proteins) present in the fungi, taking into account the n-type nature of the ZnO semiconductor and the electrical behavior of the fungal cell membrane and that of the proteins that make up the protein crown.

• 한국응급구조학회지
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• 제14권3호
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• pp.5-11
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• 2010

Purpose: This study was to clarify correlation between en route distance and role time on call received hours. Methods: Data on en route distance(dependent variable), role time(independent variable) from 387 prehospital care reports documented by EMS in Kyonggi Provincial Fire and Disaster Headquarters and Seoul Metropolitan Fire and Disaster Department between 21 and 10 June 2010 were randomly chosen for simple regression analysis using Windows SPSS 12. OK. This analysis was conducted nine times on unit hour divided to eight call received and overall. Results: Statistically significant regression equations( Y=2.414+1.206X for 09:00~11:59, Y=3.753+.662X for 12:00~14:59, Y=2.215+1.458X for 15:00~17:59, Y=2.600+.822X for 21:00~23:59, Y=5. 445+.263X for overall) were derieved from the data. Conclusion: These equations having linear relationship may be utilized as a method for system status management to effectively response to emergency call.

• 한국항행학회논문지
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• 제26권6호
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• pp.434-440
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• 2022

ICAO (international civil aviation organization)에서는 전략적인 의사결정과 항공교통관리 평가를 위해 세계항행계획인 GANP (global air navigation plan) 수행을 체약국에게 권고하였다. 본 연구에서는 항공교통관리 평가를 위해 제시된 KPI (key performance indicator) 05 실제 항로 연장에서 항로거리를 구하는 새로운 방법을 제안하였다. 이를 위해 한 달간의 항적 데이터를 수집하고 ICAO에서 제시한 방법과 본 저자가 제시하는 방법으로 각각 항로거리를 산출하였다. ICAO 방법은 반경 40 NM 원형에 대한 원의 방정식과 항적 데이터 내 원에 근접한 내·외부 지점에 대한 직선의 방정식을 통하여 교점을 추정하여야 하고, 네 가지의 비행거리를 계산하여 항로거리를 산출한다. 본 연구에서 제시한 방법은 교점을 추정하지 않고 두 가지의 비행거리를 계산하여 항로거리를 산출한다. 두 방법의 오차를 확인하기 위해 회귀모형 성능평가지표인 RMSE (root mean square error)와 결정계수 R² 를 사용하였다.

• 한국시뮬레이션학회논문지
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• 제19권1호
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• pp.161-171
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• 2010

많은 센서 네트워크 응용분야에서 센서 노드는 개방된 환경에 놓이게 된다. 공격자는 개방된 환경에 놓인 센서 노드를 물리적으로 획득할 수 있으며, 포획한 노드를 이용하여 허위보고서를 센서네트워크에 삽입 시킬 수 있다. 삽입된 허위보고서는 제한된 센서노드 에너지를 고갈 시키며, 허위 경보를 일으켜 심각한 문제를 야기 시킬 수도 있다. 이러한 공격을 막기 위해 Ye 등은 통계적 여과 기법(Statistical En-route Filtering) 방법을 제안하였다. 통계적 여과기법은 CoS(Center of Stimulus)로부터 생성된 이벤트 보고서가 베이스 스테이션으로 전송되는 동안 중간의 모든 노드들이 검증을 하게 된다. 본 논문은 통계적 여과 기법에 확률 검증 기법을 적용하여 에너지 효율적인 정적 확률 통계적 여과 기법을 제안하고자 한다. 베이스 스테이션과 이벤트 발생 지역까지의 거리가 멀어질수록 에너지 절약 효과가 극대화 될 것으로 기대된다.

• Journal of Information Processing Systems
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• 제6권3호
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• pp.375-384
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• 2010

Trajectory modeling is foundational for 4D-Route modeling, conflict detection and air traffic flow management. This paper proposes a novel algorithm based Vincenty's fomulas for trajectory calculation, combined with the Dijkstra algorithm and Vincenty's formulas. Using flight plan simulations our experimental results show that our method of En-route trajectory calculation exhibits much improved performance in accuracy.

• 한국시뮬레이션학회논문지
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• 제20권4호
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• pp.31-40
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• 2011

센서 노드는 악의적인 공격자들에 의해 물리적인 공격들에 쉽게 노출된다. 공격자는 훼손 노드를 이용하여 센서 네트워크에 다양한 공격을 발생시킬 수 있다. 그 중 응용 계층에서 발생하는 허위 보고서 삽입 공격은 훼손된 노드를 통해 네트워크 내에 위조 보고서를 주입한다. 주입된 위조 보고서는 BS까지 전달될 경우 허위 경보뿐만 아니라 노드의 불필요한 에너지 소모를 유발한다. 이러한 공격을 방어하기 위해 통계적 여과 기법은 BS까지 전달되는 허위 보고서를 전달 과정 중 가능한 빨리 여과시키기 위해 제안되었다. 이 기법의 성능 향상을 위해 제안된 기법 중 경로 갱신 기법은 통계적 여과 기법의 탐지 능력 유지하고 노드의 균형 있는 에너지 소모를 위해 제안되었다. 본 논문은 경로 경신 방법에서 경로 갱신에 필요한 에너지의 효율적인 소비를 위해 보안 경로 주기 결정 방법을 제안한다. 보안 경로 주기를 선택하기 위해 BS에서 센서 노드들의 홉 수와 보고서 전송량을 고려하여 평가 함수를 통해 결정한다. 그리고 시뮬레이션을 통해 위 3가지 기법들과 제안 기법을 비교하여 에너지 효율성을 평가한다. 그러므로 제안 기법은 보안 경로 설정을 유지하면서, 네트워크 내에 균형 있는 에너지 소비의 효율을 높인다.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1997년도 7월 학술대회지
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• pp.179-184
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• 1997

• 한국항공운항학회지
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• 제18권2호
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• pp.1-8
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• 2010

In order to determine the possibility of using NDGPS signals for flight operations, in-flight measurements of signals transmitted from various ground reference stations(RS) were conducted along the air routes of South Korea. Signal strength and signal to noise ratio(SNR) data were collected along domestic flight routes and recorded with time. By using three-dimensional geographical position data of the aircraft, signal strength data of en-route position were calculated and used to obtain scatter-plot of signal strength. These results were used to outline the effective coverage and field strength hemispheres of the selected DGPS signals.