• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.167-170
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• 2017

Objective: The feed intake (FI) and feed efficiency are economically important traits in ducks. To obtain insight into this economically important trait, we designed an experiment based on the residual feed intake (RFI) and feed conversion ratio (FCR) of a random population Pekin duck. Methods: Two thousand and twenty pedigreed random population Pekin ducks were established from 90 males mated to 450 females in two hatches. Traits analyzed in the study were body weight at the 42th day (BW42), 15 to 42 days average daily gain (ADG), 15 to 42 days FI, 15 to 42 days FCR, and 15 to 42 days RFI to assess their genetic interrelationships. The genetic parameters for feed efficiency traits were estimated using restricted maximum likelihood (REML) methodology applied to a sire-dam model for all traits using the ASREML software. Results: Estimates heritability of BW42, ADG, FI, FCR, and RFI were 0.39, 0.38, 0.33, 0.38, and 0.41, respectively. The genetic correlation was high between RFI and FI (0.77) and moderate between RFI and FCR (0.54). The genetic correlation was high and moderate between FCR and ADG (-0.80), and between FCR and BW42 (-0.64), and between FCR and FI (0.49), respectively. Conclusion: Thus, selection on RFI was expected to improve feed efficiency, and reduce FI. Selection on RFI thus improves the feed efficiency of animals without impairing their FI and increase growth rate.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.56-65
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• 2009

The single device that is combined more than one communication systems in shared band is called collocated system. In this paper, the collocated system is made by combination of Wi-Fi and WiMAX system. Performance of the collocated system is analysed by using two communication model, Collaborative and Non-Collaborative. To minimize the mutual interference between Wi-Fi and WiMAX system in collocated system, the circulator-based collocated system is proposed and analysed it's performance characteristics.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.353-359
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• 2022

Several suture patterns can be used for cystotomy closure, and a continuous suture pattern is the most commonly used. In this study, the fluid-tight ability and other suitabilities of continuous appositional sutures, such as the simple continuous suture pattern (SC), running suture pattern (RN), and Ford interlocking suture pattern (FI), were compared for cystotomy closure. Cystotomy closure was performed using each suture method in 10 cases of ex vivo swine bladders in each group. Suture time, leakage site, suture length, bursting pressure (BP), bursting volume (BV), and circular bursting wall tension (CBWT) were measured. Suture time and suture length were the shortest in RN and the longest in FI. Leakage occurred in two places: the incision line directly and the hole made by the suture. Leakage occurred through the incision line in 4 bladders of the RN group and 2 bladders of the FI group, but not in the SC group, and in the rest of the bladders, leakage occurred through the suture hole. The values of BP, BV, and CBWT increased in the order of FI, SC, and RN. Suture time and suture length can be considered as factors related to healing and side effects. In this study, leakage through the incision was found in a less appositional area; therefore, leakage through the hole could be considered an indicator of better apposition. Good apposition is one of the conditions required for ideal cystotomy closure. The bursting strength representing the fluid-tight ability can be expressed as the CBWT. RN is expected to be efficient and cause a small degree of foreign body reaction; however, it is expected to be less stable. FI has the greatest fluid-tightness ability, but it has been proposed that side effects due to foreign body reactions most frequently occur in FI. In conclusion, SC, which is expected to have a sufficient degree of fluid-tightness and appropriate recovery, is preferable to other continuous appositional suturing methods for cystotomy closure.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.975-976
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• 2016

Beacon 기술은 배터리 소모가 적고 간편하게 장치와의 거리를 측정할 수 있어 여러 분야에 사용되고 있지만 장애물의 간섭에 약하다는 문제점이 있다. 따라서 본 논문에서는 이러한 문제를 개선하고자 간섭에 강한 WiFi 환경과 오픈소스 Frameware인 OpenWrt를 이용해 Raspberry pi를 AP화 시켜 Beacon 장치를 탐지하여 수신한 데이터를 사설 네트워크 내 장치들에게 안정적으로 전달할 수 있는 장치를 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.3
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• pp.794-814
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• 2012

We propose a novel method for improving Wi-Fi positioning accuracy while reducing the energy consumption of mobile devices. Our method presents three contributions. First, we jointly and intelligently select the optimal subset of access points for positioning via maximum mutual information criterion. Second, we further propose local discriminant embedding algorithm for nonlinear discriminative feature extraction, a process that cannot be effectively handled by existing linear techniques. Third, to reduce complexity and make input signal space more compact, we incorporate clustering analysis to localize the positioning model. Experiments in realistic environments demonstrate that the proposed method can lower energy consumption while achieving higher accuracy compared with previous methods. The improvement can be attributed to the capability of our method to extract the most discriminative features for positioning as well as require smaller computation cost and shorter sensing time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1138-1143
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• 2013

In this paper, we propose a smartphone application based on a wireless fidelity(WiFi) in order to control the charging of electric vehicle(EV) and monitor the charging status together with the vehicle history information. The driver obtains much information on vehicle status through a smartphone application which communicates with the electric vehicle supply equipment(EVSE) management server while the EV also communicates with the EVSE for the authentification through controller area network(CAN). We also implement the simulator for the EV charging control system to verify the functions of the proposed application where the simulator consists of an EV model, an EVSE, and a smartphone. It is shown by the simulator that the proposed smartphone application allows the driver to control and to monitor the charging process of an EV conveniently and, moreover, it can provide the driver with vehicle information stored in the EVSE management server.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.7
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• pp.684-690
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• 2015

This paper presents a modified residual-based EKF (Extended Kalman Filter) for performance improvement of indoor positioning using WiFi RSSI (Received Signal Strength Indicator) measurement. Radio signal strength in indoor environments may have irregular attenuation characteristics due to obstacles such as walls, furniture, etc. Therefore, the performance of the RSSI-based positioning with the conventional trilateration method or Kalman filter is insufficient to provide location-based accurate information services. In order to enhance the performance of indoor positioning, in this paper, error analysis of the distance calculated by using the WiFi RSSI measurement is performed based on the radio propagation model. Then, an IARM (Irregularly Attenuated RSSI Measurement) error is defined. Also, it shows that the IARM error is included in the residual of the positioning filter. The IARM error is always positive. So, it is presented that the IARM error can be estimated by taking the absolute value of the residual. Consequently, accurate positioning can be achieved based on the IEM (IARM Error Mitigated) EKF with the residual modified by using the estimated IARM error. The performance of the presented IEM EKF is verified experimentally.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.4
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• pp.1200-1215
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• 2023

With the development of IoT and artificial intelligence, location-based services are getting more and more attention. For solving the current problem that indoor positioning error is large and generalization is poor, this paper proposes a Model Stacking Algorithm for Indoor Positioning System using WiFi fingerprinting. Firstly, we adopt a model stacking method based on Bayesian optimization to predict the location of indoor targets to improve indoor localization accuracy and model generalization. Secondly, Taking the predicted position based on model stacking as the observation value of particle filter, collaborative particle filter localization based on model stacking algorithm is realized. The experimental results show that the algorithm can control the position error within 2m, which is superior to KNN, GBDT, Xgboost, LightGBM, RF. The location accuracy of the fusion particle filter algorithm is improved by 31%, and the predicted trajectory is close to the real trajectory. The algorithm can also adapt to the application scenarios with fewer wireless access points.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.564-573
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• 2015

GPS is the representative positioning technology for providing the location information. This technique has the disadvantage that does not operate in the shadow areas, such as urban or dense forest and the interior. This paper proposes a hybrid indoor positioning algorithm, which estimates a more accurate location of the terminal using strength of the Wi-Fi signal from the indoor AP. To determine the location of the user, we establish the most appropriate path loss model for the measurement environment. by using the RSSI value measured in a variety of environment such as building structure, person, distance, etc. The path loss exponent obtained by the path loss model is changed according to the environment. REKF, PF estimate the position of the terminal by using measured value from the AP with path loss exponent. For more accurate position estimation, we select positioning system by the value of threshold measured by experiments rather than a single positioning system. Experimental results using the proposed hybrid algorithm show that the performance is improved by about 17% than the conventional single positioning method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.7
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• pp.553-563
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• 2013

When the IEEE 802.11 wireless LAN-based broadcasting services, we use broadcast packets to broadcast multimedia contents to a large number of users using limited wireless resources. However, broadcast transmission is difficult to recover the loss packets compared with unicast transmission. Therefore, analysis of packet loss characteristics is required to perform efficient packet recovery. The packet loss in wireless transmissions is often bursty with high loss data rate. Even if loss patterns have the same average packet loss, they are different in the recovery rate of random loss and burst loss depending on the nature. Therefore, the analysis and research of the nature of the loss are needed to recover loss packets considering bursty characteristics. In this paper, we experimented Wi-Fi broadcast transmission according to transmission rate and analyzed bursty characteristics of loss patterns using 4-state markov model.