• International Journal of Advanced Culture Technology
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• 제8권1호
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• pp.243-247
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• 2020

In the era of the fourth industrial revolution, safety of disasters is being emphasized above all else, and electric fires are most frequent during disasters, and human and property damage is very serious. In this paper, we propose a study that can determine the efficiency of evacuation and non-evacuation guidance due to the large difference in casualties depending on the traffic line in the case of fire. Evacuation guidance was assumed to be a situation in which adequate evacuation routes were guided by a recorded voice or a trained staff, and non-evacuation guidance was assumed to be a situation without anything. Evacuation simulations were carried out using a evacuation simulation tool called PATHFINDER and SIMULEX for the analysis of the efficiency of evacuation and non-evacuation guidance. As a result, the evacuation time was similar, but in the case of non-evacuation guidance, it was not guided to the safe zone, which could cause serious damage.

• 대한조선학회논문집
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• 제42권4호
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• pp.299-306
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• 2005

To determine a guidance law which is suitable for Target Tracking System(TTS) of an underwater vehicle, the performance (hitting probability) of TTS were calculated with four different guidance schemes, considering underwater vehicle's manoeuvrability and characteristics of seeking equipment such as sonar To evaluate the performance of TTS with each guidance law, numerous target-tracking simulations of underwater vehicle were performed under the condition of target's various motion scenario. Furthermore, the effect of sonar characteristics to the performance of guidance law in TTS was studied by changing parameters of sonar such as frequency of ping and detecting error of target. The pursuit-tail guidance law showed the best performance among four different guidance laws. Complex motion of target from straight line to turning circle and zigzag movement, low frequency of sonar ping and large detecting error of target decreased the hitting probability.

• 한국항공우주학회지
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• 제39권1호
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• pp.16-24
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• 2011

본 논문에서는 충돌각 및 종말 가속도를 제어하는 $t_{go}$-다항식 유도기법을 기반으로 표적 가관측성을 향상시키는 새로운 형태의 $t_{go}$-다항식 유도법칙을 제안한다. 제안한 유도법칙은 기존 $t_{go}$-다항식 유도명령에 거리오차와 비례이득으로 구성된 부가항을 합한 간단한 형태로서, 비례이득을 변화시킴에 따라 비행궤적의 형태를 결정할 수 있다. 또한 이는 $t_{go}$-다항식 유도가 가지는 충돌각 및 가속도 제어 특성을 그대로 유지한다. 본 연구에서는 제안한 유도법칙의 닫힌 해를 구하여 유도 특성을 고찰하고, 다양한 시뮬레이션을 수행하여 유도법칙의 타당성을 보이도록 한다.

• 한국항공우주학회지
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• 제40권10호
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• pp.853-861
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• 2012

본 논문에서는 주어진 3단형 발사체의 상단부 폐루프 유도 방식 선정을 위해 널리 알려져 있는 Space Shuttle의 PEG 알고리듬보다 유도명령의 형태가 최적화 해에 가까운 Jaggers가 제안한 직접식 유도 방식에 대해서 다루었다. 이 알고리듬을 주어진 발사체의 상단부인 2단 및 3단 비행 구간에 적용할 경우에 대해서 유도 성능을 분석했다. 또한 보다 정밀한 유도를 위해 알고리듬 유도를 위해 사용된 근사식들을 가능한 사용하지 않도록 했으며 원래의 알고리듬에 비해 성능이 개선됨을 확인하였다.

• 한국식품영양학회지
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• 제33권4호
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• pp.406-418
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• 2020

This study aimed to investigate the dietary guidelines from the dietitians and parents' perceptions in kindergarten. The survey was carried out by 39 dietitians and 320 parents in kindergarten of Sejong city from April 18 to May 14, 2019. Approximately, 48.6% of dietitians responded that the amount of food provided was adjusted according to the age and weight of the infant. Both dietitians and parents responded the most to 'to build the right eating habits' as the reason for dietary guidance. As a guiding method for infants who sneaked unpleasant food, 62.9% of dietitians responded 'teach them about the wrong behavior on the spot', and 63.7% of parents stated 'talk about wrong behavior later'. The necessity of linking the dietary guidance between kindergarten and the family was recognized by dietitians and parents. The most important content for the linkage of the dietary guidance was 'correct eating manners and attitude'. The biggest problem in the dietitian's dietary guidance was the guidance on an unbalanced diet. Our results indicated differences in the dietary guidance contents of dietitians' and parents' perception of importance. Apparently, it is considered essential to link kindergarten with the family to provide correct and effective guidance for children.

• 한국항공우주학회지
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• 제36권8호
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• pp.747-752
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• 2008

본 논문에서는 추적-회피 게임의 해를 기반으로 한 유도법칙을 제안하고, 성능을 분석한다. 추적자를 유도하는데 게임 해의 초기 값을 사용하고, 다음 단계에서 추적-회피 게임의 해를 다시 계산한다. 이 점에 있어서 제안된 유도법칙은 모델예측제어와 유사하다. 회피자가 요격시간을 최대화하는 방향으로 항상 기동하는 추적-회피 시나리오에 대하여, 비례항법유도와 비교한 결과, 제안된 유도기법이 더 넓은 요격영역을 가진다는 것을 확인하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제15권1호
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• pp.97-112
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• 2023

The purpose of this study is to design and test a new way of public transportation route guidance system for persons with disabilities, including wheelchair users. The guidance system is smartphone app-based, using, routes that involve disabled-friendly facilities in the vicinity can be searched. A database that contains publicly available data on low-floor bus services, location and extent of disabled-friendly facilities, and suitable subways and stations, was developed for this purpose. The app uses the database to access and query the required information. A pilot study was conducted to test the effectiveness of the guidance system. It was found that the system was able to convey information about the disabled-friendly routes and related guidance information even inside subway stations, effectively. The performance of the system was compared with route guidance services that do not explicitly use data on disabled-friendly services. A notable difference was observed in the travel time estimated by this program and other guidance services. The difference was around 4 to 15 minutes. This is significant savings for persons with disabilities if they use the app and service. The study thus shows that exclusive use of disabled-friendly data in route guidance will bring more benefits for persons with disabilities.

• 한국해양공학회지
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• 제30권1호
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• pp.32-43
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• 2016

A UUV needs to have a robust path following performance because of unpredicted current disturbances. Because the desired path of a UUV is usually designed by considering the locations of obstacles or geographical features of the operation region, the UUV should stay on the desired path to avoid damage or loss of the vehicle. However, conventional path following methods cannot deal with strong countercurrent disturbances. Thus, the UUV may deviate from the desired path. In order to avoid such deviation, a backward path following method is suggested. This paper proposes a path following method that combines pure pursuit guidance and nonlinear guidance for the UUV under an unpredicted strong ocean current. For a stable path following system, this paper suggests that the UUV adjust its heading to the current direction using the pure pursuit guidance method when the system is in an unstable region, or the UUV follows the desired path with nonlinear guidance. By combining the pure pursuit guidance and nonlinear guidance, it was possible to overcome the drawbacks of each path following method in the reverse path following case. The efficiency of the proposed method is shown through simulation results compared to those of the pure pursuit method and nonlinear guidance method.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.190-196
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• 2013

This paper proposes a new guidance law, which considers the Field of View (FOV) of the seeker when a missile has a strapdown seeker mounted instead of a gimbal seeker. When a strapdown seeker, which has a narrow FOV, is used for tracking a target, the FOV of the seeker is an important consideration for guidance performance metrics such as miss distance. We propose a new guidance law called hybrid guidance (HG) to address the shortcomings of conventional guidance laws such as proportional navigation guidance (PNG), which cannot maintain lock-on conditions against high speed targets due to the narrow FOV of the strapdown seeker. The aim of the HG law is to null miss distance and to maintain the look angle within the FOV of the strapdown seeker. In order to achieve this goal, we combine two guidance laws in the HG law. One is a PNG law to null the LOS rate, and the other is a sliding mode guidance (SMG) law derived to keep the look angle within the FOV by employing a Lyapunov-like function with a sliding mode control methodology. We also propose a method to switch these two guidance laws at certain look angles for better guidance performance.

• 제어로봇시스템학회논문지
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• 제9권4호
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• pp.320-328
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• 2003

This paper proposes a new nonlinear adaptive guidance law. Fourth order state equation for integrated guidance and control loop is formulated considering target uncertainties and control loop dynamics. The state equation is further changed into the normal form by nonlinear coordinate transformation. An adaptive nonlinear guidance law is proposed to compensate for the uncertainties In both target acceleration and control loop dynamics. The proposed law adopts the sliding mode control approach with adaptation fer unknown bound of uncertainties. The present approach can effectively solve the existing guidance problem of target maneuver and the limited performance of control loop. We provide the stability analyses and demonstrate the effectiveness of our scheme through simulations.