• 대한인간공학회지
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• 제24권2호
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• pp.45-49
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• 2005

The FSA(Force Sensitive Application) system measures hand force by using force resistance sensors. Compared to conventional hand force measurement systems such as Lafayette hand dynamometer and Jamar hydraulic hand dynamometer, the FSA system can be applied to analyze use of hand forces while the hand is manipulating objects for a task, However, the measurement performance of the FSA system has not been objectively evaluated. The present study tested the FSA system in terms of stability, repeatability, accuracy, and linearity. It is shown that the FSA system has good stability (CV$\leq$0.02) and linearity($R^2$=0.82), but has low repeatability(CV=$0.11{\sim}0.19$) and accuracy(22% of underevaluation on average). This performance result indicates that measurements from the FSA system should be used for relative comparison rather than for absolute comparison.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.165-182
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• 2014

An RFID systems employ efficient Anti-Collision Algorithms (ACAs) to enhance the performance in various applications. The EPC-Global G2 RFID system utilizes Frame Slotted Aloha (FSA) as its ACA. One of the common approaches used to maximize the system performance (tag identification efficiency) of FSA-based RFID systems involves finding the optimal value of the frame length relative to the contending population size of the RFID tags. Several analytical models for finding the optimal frame length have been developed; however, they are not perfectly optimized because they lack precise characterization for the timing details of the underlying ACA. In this paper, we investigate this promising direction by precisely characterizing the timing details of the EPC-Global G2 protocol and use it to derive a precise-optimal frame length model. The main objective of the model is to determine the optimal frame length value for the estimated number of tags that maximizes the performance of an RFID system. However, because precise estimation of the contending tags is difficult, we utilize a parametric-heuristic approach to maximize the system performance and propose two simple schemes based on the obtained optimal frame length-namely, Improved Dynamic-Frame Slotted Aloha (ID-FSA) and Exponential Random Partitioning-Frame Slotted Aloha (ERP-FSA). The ID-FSA scheme is based on the tag set estimation and frame size update mechanisms, whereas the ERP-FSA scheme adjusts the contending tag population in such a way that the applied frame size becomes optimal. The results of simulations conducted indicate that the ID-FSA scheme performs better than several well-known schemes in various conditions, while the ERP-FSA scheme performs well when the frame size is small.

• 한국항해항만학회지
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• 제41권5호
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• pp.287-296
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• 2017

The Formal Safety Assessment (FSA) is a structured and systematic methodology developed by the IMO, aimed at assessing the risk of vessels and recommending the method to control intolerable risks, thereby enhancing maritime safety, including protection of life, health, the marine environment and property, by using risk analysis and cost-benefit assessment. While the FSA has mostly been applied to merchant vessels, it has rarely been applied to a DP vessel, which is one of the special purpose vessels in the offshore industry. Furthermore, most of the FSA has been conducted so far by using the Fault Tree Analysis tool, even though there are many other risk analysis tools. This study carried out the FSA for safe operation of DP vessels by using the Bayesian network, under which conditional probability was examined. This study determined the frequency and severity of DP LOP incidents reported to the IMCA from 2001 to 2010, and obtained the Risk Index by applying the Bayesian network. Then, the Risk Control Options (RCOs) were identified through an expert brainstorming and DP vessel simulations. This study recommends duplication of PRS, regardless of the DP class and PRS type and DP system specific training. Finally, this study verified that the Bayesian network and DP simulator can also serve as an effective tool for FSA implementation.

• 한국정보통신학회논문지
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• 제12권9호
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• pp.1569-1574
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• 2008

13.56MHz ISM 대역을 사용하는 대부분의 RFID 시스템은 슬롯 ALOHA 방식을 기반으로 하는 고정된 프레임 크기를 갖는 FSA 알고리즘을 충돌 방지 알고리즘으로 사용하고 있다. FSA 알고리즘의 경우, 알고리즘의 구현이 간단한 장점이 있지만, 프레임의 크기가 고정되어 있기 때문에 태그 수가 가변적인 경우에는 시스템 성능이 저하되는 단점이 있다. 따라서 본 논문에서는 리더의 식별 영역 내에 있는 태그의 수를 기반으로 매 프레임마다 최적의 프레임 크기를 할당하는 OFSA 알고리즘을 제안한다. 시뮬레이션을 통한 성능 분석의 결과, OFSA 알고리즘은 기존의 FSA 알고리즘에 비하여 항상 최적의 시스템 효율을 얻을 수 있었으며, 최소의 식별 지연 시간을 얻을 수 있었다.

• 한국전기전자재료학회논문지
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• 제20권5호
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• pp.462-466
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• 2007

The measuring system of the Partial discharge(PD) is very essential to investigate the hazard defects in the insulation systems of the high voltage engineering. We will discussed this research which has included two parts. The proposed method of Foil Sensor Array(FSA) and the normally used method in the practice. Firstly, it will be shown the improved sensitivity of a FSA sensor, which is our aim, compare with the existing normal foil sensor. And then, the linearity of detecting sensitivities of various kinds of FSA sensors was shown. According to our experiments, we can see that FSA sensor is more sensitivity than normal foil sensor and the linear increment property of FSA sensitivities.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.164-169
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• 2009

An RFID system consists of radio frequency tags attached to objects that need to be identified and one or more electromagnetic readers. Unlike the traditional bar code system, the great benefit of RFID technology is that it allows information to be read without requiring contact between the tag and the reader. For this contact-less feature, RFID technology in the near future will become an attractive alternative to bar code in many application fields. In almost all the 13.56MHz RFID systems, FSA (Framed Slot ALOHA) algorithm is used for identifying multiple tags in the reader's identification range. In FSA algorithm, the tag identification time and system efficiency depend mainly on the number of tags and frame size. In this paper, we propose a tag number estimation scheme and a dynamic frame size allocation scheme based on the estimated number of tags.

• 한국정보통신학회논문지
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• 제13권3호
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• pp.469-474
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• 2009

RFID 시스템은 식별되고자하는 사물에 부착된 태그들과 이를 인식하는 리더로 구성된다. 기존의 바코드 시스템과는 달리, 태그와 리더간에 접촉이 없이도 저장된 정보를 읽을 수 있는 특징이 있다. 이러한 비접촉 특성으로 인하여 RFID 기술은 다양한 응용 분야에서 바코드를 대신할 기술이 될 것이다. 13.56MHz 대역을 사용하는 대부분의 RFID 시스템은 리더 의 식별 영역에 있는 다중 태그를 식별하기 위하여 FSA 알고리즘을 사용한다. FSA 알고리즘인 경우, 식별 영역내에 있는 태그의 수와 프레임의 크기에 따라 태그식별 지연 시간과 시스템 효율이 크게 변화한다. 본 논문에서는 이러한 RFID 시스템에서 태그의 수를 추정하고, 추정한 태그의 수를 기반으로 프레임 크기를 동적으로 할당하는 기법을 제안한다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.739-746
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• 2016

A total of 152 pig farms were randomly selected from the five provinces in South Korea. During the experiment, the average temperature and relative humidity was $24.7^{\circ}C$ and 74% in summer and $2.4^{\circ}C$ and 53% in winter, respectively. The correlation between floor space allowance (FSA) and productivity index was analyzed, including non-productive sow days (NPD), number of weaners (NOW), survival rate (SR), appearance rate of A-grade pork (ARA), and days at a slaughter weight of 110 kg (d-SW) at different growth stages. The objectives of the present study were i) to determine the effect of FSA on the pig productivity index and ii) to suggest the minimum FSA for pigs based on scientific baseline data. For the pregnant sow, NPD could be decreased if pregnant sows were raised with a medium level (M) of FSA (3.10 to $3.67m^2/head$) while also keeping the pig house clean which improves hygiene, and operating the ventilation system properly. For the farrowing sows, the NOW tended to decrease as the FSA increased. Similarly, a high level of FSA (H) is significantly negative with weaner SR of farrowing sows (p-value = 0.017), indicating this FSA tends to depress SR. Therefore, a FSA of 2.30 to $6.40m^2/head$ (very low) could be appropriate for weaners because a limited space can provide a sense of security and protection from external interruptions. The opposite trend was observed that an increase in floor space (> $1.12m^2/head$ leads to increase the SR of growing pigs. For the fattening pigs, H level of FSA was negatively correlated with SR, but M level of FSA was positively correlated with SR, indicating that SR tended to increase with the FSA of 1.10 to $1.27m^2/head$. In contrast, ARA of male fattening pigs showed opposite results. H level of FSA (1.27 to $1.47m^2/head$) was suggested to increase productivity because ARA was most affected by H level of space allowance with positive correlation ($R^2=0.523$). The relationship between the FSA and d-SW of fattening pigs was hard to identify because of the low $R^2$ value. However, the farms that provided a relatively large floor space (1.27 to $1.54m^2/head$) during the winter period showed d-SW was significantly and negatively affected by FSA.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.158-159
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• 2006

The system measuring the Partial discharge(PD) is very essential to investigate the hazard defects in the insulation systems of the high voltage engineering. We included two parts in this discussion; The proposed method of Foil Sensor Array and the normally used method m the practice. Firstly, it will be shown the improved sensitivity of our proposed FSA sensor compare with the existing normal foil sensor. And then, the linearity of detecting sensitivities of various kinds of FSA sensors such as $2{\times}2$, $2{\times}4$, $3{\times}3$ etc. using in our experiments, was shown. From the obtained results, we can see that FSA sensor is more sensitivity than normal foil sensor and the linear increment property of FSA sensitivities.

• 한국정보통신학회논문지
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• 제10권5호
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• pp.806-811
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• 2006

RFID 시스템에서 태그들이 동시에 응답을 하면 충돌이 발생하며, 이를 해결하는 기술이 충돌방지 알고리즘이다. 기존의 충돌방지 알고리즘 중에서 SFSA (Static Framed Slot ALOHA) 알고리즘은 구현이 간단한 장점이 있지만, 프레임의 크기가 고정되어 있기 때문에 태그 수가 가변적인 경우에는 시스템 성능이 저하되는 단점이 있다. 따라서 본 논문에서는 충돌이 발생한 슬롯의 수를 이용하여 매 프레임마다 최적의 프레임 크기를 결정하는 DFSA (Dynamic FSA) 알고리즘을 제안한다. 성능 분석의 결과, DFSA 알고리즘은 기존의 SFSA알고리즘에 비하여 빠른 태그 식별이 가능함을 알 수 있었다.