• International Journal of Industrial Entomology and Biomaterials
• /
• v.47 no.2
• /
• pp.79-89
• /
• 2023

This paper is about the development results of an automatic silkworm breeding system to reduce labor and time by automatically performing the works for silkworm droppings changing and feed its food. It consists of an automatic guided vehicle and a processing unit. The automatic guided vehicle transports a silkworm dropping changing frame mounted on a silkworm tray stand, and the processing unit takes over the dropping changing frame on it, removes excrement contained the droppings changing frame and feeds silkworm food. In the case of the current silkworm farming, because the breeding period for large silkworms (4 to 5 stage) is short to 14 days and the supply of mulberry leaves takes 98% of the total amount of mulberry leaves needed for breeding silkworms at this time, labor concentration is intensive, and all breeding works depends on manpower. Therefore, it was difficult to breed large silkworms on a large scale. Moreover, silkworms are bred by adding Silkworm bed (Seop) and mulberry in the silkworm tray, and their droppings changing is to separate silkworms and excrement by moving silkworm trays one by one, and the production cost increases due to the high-cost manpower for silkworm breeding. To solve this problem, technology for automating silkworm breeding has also been developed. However, there is still a limitation that silkworm feeding and droppings changing works are not suitable for mass breeding because a lot of labor and time are spent depending on manual work. Therefore, a new silkworm breeding system for breeding silkworm automatically is needed and so we developed an Automatic Silkworm Breeding System applying the droppings change frame, the inverting unit, the feeding silkworm food device and automatic guided vehicle.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2000.11a
• /
• pp.44-48
• /
• 2000

In this study was modify the PRMA for supporting various types of traffic classes such as CBR, VBR, ABR and UBR. For uplink, we use reservation slots and so the performance will not degrade in case of over load conditions. For downlink broadcasting slots for informing the status of slot reservations are used so the high priority priority terminal can preempt. And we use almost same size buffer as the frame size. So we can dynamically deal with, the traffic changes of VBR terminals. It makes easy for the terminals to reserve supplementary slots. Each terminal is reallocated by the priority of traffic classes and so we can easily select the dropping packets in case of overload conditions. As a result, using our scheme, we can get high channel efficiency and get low packet dropping ratio and delay.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2003.11a
• /
• pp.115-118
• /
• 2003

다양한 종류의 사용자 단말과 더불어 이종 망의 도입에 따라, 디지털 영상컨텐츠를 효과적으로 제공하기 위해 트랜스코딩에 대한 연구가 활발히 진행 중에 있다. 특히, FD(Frame Dropping)/CD(Coefficient Dropping) 트랜스코딩기법은 계산량을 줄이고, 손쉽게 구현할 수 있다는 측면에서 주목을 받고 있다. 그러나, 기존의 연구에서는 CD로 인하여 발생되는 왜곡 특성이 GOP내의 다른 복호화 영상 품질에 전파 및 누적되는 성질을 고려하지 않고 있다. 본 논문에서는 CD로 인하여 발생되는 왜곡을 수식적으로 분석하고, CD왜곡이 전파/누적됨을 모의실험을 통하여 분석한다. 또한, 실험적인 견과에 기초하여,0에 의한 전파/누적 왜곡 특성을 지수 감소함수 형태로 모델링 될 수 있음을 보이고, 모의실험을 통하여, 제안된 모델링은 CD로 인해 발생하는 전체 복호화 왜곡 크기를 잘 예측하는데 사용할 수 있음을 보인다.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2003.05b
• /
• pp.90-95
• /
• 2003

다수의 사용자 요구에 의한 비디오 타이틀을 실시간으로 제공해야 하는 VOD 서비스는 클라이언트의 버퍼 안정화와 재생 질 보증을 위해서는 네트워크의 상태를 주기적으로 모니터링하여 그 상태에 따라 디스크 배열에 저장되어 있는 프레임을 드로핑(Dropping)이나 스키핑(Skipping) 알고리즘으로 프레임을 전송하는 메카니즘이 필요하다. 본 논문에서는 MPEG을 이용하여 일반 VHS 비디오 테이프의 내용을 손실 압축하여 디스크 배열에 저장해 두고, 디스크 배열에 압축 저장된 MPEG 프레임(I, P, B 프레임) 데이터를 네트워크의 부하에 따라 저장장치에서 생략 인출하여 클라이언트에 전송하는 알고리즘을 제시한다. 또한 시뮬레이션을 통해 네트워크의 부하에 적응적으로 대처하여 네트워크의 부하를 줄이고 클라이언트의 수신 버퍼를 안정화시킬 수 있음을 검증한다.

• Earthquakes and Structures
• /
• v.24 no.3
• /
• pp.205-215
• /
• 2023

Currently, many studies are underway at home and abroad on the seismic performance evaluation and dry construction method of the masonry structure. In this study, a dry stack masonry wall system without mortar using concrete blocks is proposed, and investigate the seismic performance of dry filling wall frames through experimental studies. First, two types of standard blocks and key blocks were designed to assemble dry walls of concrete blocks. And then, three types of experiments were manufactured, including pure frame, 1/2 height filling wall frame, and full height filling wall frame, and cyclic load experiments in horizontal direction were performed to analyze crack patterns, load displacement history, rebar deformation yield, effective stiffness change, displacement ductility, and energy dissipation capacity. According to the experimental results, the full height filling wall frame had the largest horizontal resistance against the earthquake load and showed a high energy dissipation capacity. However, the 1/2 height filling wall frame requires attention because the filling wall constrains the effective span of the column, limiting the horizontal displacement of the frame. In addition, the concrete block was firmly assembled in the vertical direction of the wall as the horizontal movement between the concrete blocks was allowed within installation margin, and there was no dropping of the assembled concrete block.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.10A
• /
• pp.886-895
• /
• 2005

As the networked media technology have been grown in recent, there have been many research works to deliver high-quality video such as HDV and HDTV over the Internet. To realize high-quality media service over the Internet, however, the network adaptive streaming scheme is required to adopt to the dynamic fluctuation of underlying networks. In this paper, we design and implement the network-adaptive HD(high definition) MPEG-2 streaming system employing the frame-based prioritized packetization. Delivered video is inputted from the JVC HDV camera to the streaming sewer in real-time. It has a bit-rate of 19.2 Mbps and is multiplexed to the MPEG-2 TS (MPEG-2 MP@HL). For the monitoring of network status, the packet loss rate and the average jitter are measured by using parsing of RTP packet header in the streaming client and they are sent to the streaming server periodically The network adaptation manager in the streaming server estimates the current network status from feedback packets and adaptively adjusts the sending rate by frame dropping. For this, we propose the real-time parsing and the frame-based prioritized packetization of the TS packet. The proposed system is implemented in software and evaluated over the LAN testbed. The experimental results show that the proposed system can enhance the end-to-end QoS of HD video streaming over the best-effort network.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.6
• /
• pp.27-32
• /
• 2005

An effective video watermarking algorithm is proposed to protect the copyright. The watermarking procedure is based on a three-dimensional discrete wavelet transform (3D DWT) and spread spectrum sequences. Two perceptual binary watermarks are preprocessed using mixing and pseudorandom permutation. After dividing the video sequence into video shots, the 3D DWT is performed, then the preprocessed watermarks are embedded into the 3D DWT coefficients, while considering robustness and invisibility, using two spread spectrum sequences defined as the user key. Experimental results show that the watermarked frames are subjectively indistinguishable from the original frames, plus the proposed video watermarking algorithm is sufficiently robust against such attacks as low pass filtering, frame dropping, frame average, and MPEG coding.

• ETRI Journal
• /
• v.27 no.4
• /
• pp.341-354
• /
• 2005

The adaptation of video according to the heterogeneous and dynamic resource constraints on networks and devices, as well as on user preferences, is a promising approach for universal access and consumption of video content. For optimal adaptation that satisfies the constraints while maximizing the utility that results from the adapted video, it is necessary to devise a systematic way of selecting an appropriate adaptation operation among multiple feasible choices. This paper presents a general conceptual framework that allows the formulation of various adaptations as constrained optimization problems by modeling the relations among feasible adaptation operations, constraints, and utilities. In particular, we present the feasibility of the framework by applying it to a use case of rate adaptation of MPEG-4 video with an explicit modeling of adaptation employing a combination of frame dropping and discrete cosine transform coefficient dropping, constraint, utility, and their mapping relations. Furthermore, we provide a description tool that describes the adaptation-constraint-utility relations as a functional form referred to as a utility function, which has been accepted as a part of the terminal and network quality of service tool in MPEG-21 Digital Item Adaptation (DIA).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.4A
• /
• pp.421-430
• /
• 2006

In this paper, we propose a practical implementation of network-adaptive HD(high definition) MPEG-2 video streaming with a cross-layered channel monitoring(CLM) over the IEEE 802.11a WLAN(wireless local area network). For wireless channel monitoring, AP(access point) periodically measures the MAC(medium access control) layer transmission information and sends the monitoring information to a streaming server. This makes that the streaming server reacts more quickly as well as efficiently to the fluctuated wireless channel than that of the end-to-end monitoring(E2EM) scheme for the video adaptation. The streaming sewer dynamically performs the priority-based frame dropping to adjust the video sending rate according to the measured wireless channel condition. For this purpose, our streaming system nicely provides frame-based prioritized packetization by using a real-time stream parsing module. Various evaluation results over an IEEE 802.11a WLAM testbed are provided to verify the intended QoS adaptation capability The experimental results show that the proposed system can effectively mitigate the quality degradation of video streaming caused by the fluctuations of time-varying wireless channel condition.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.189-192
• /
• 2000

This paper proposes a fuzzy-based random access controller with a superimposed frame structure (F$^2$RAC) fur voice/data-integrated wireless networks. F$^2$RAC adopts mini-slot technique for reducing contention cost, and these mini-slots of which number may dynamically vary from one frame to the next as a function of the traffic load are further partitioned into two regions for access requests coming from voice and data traffic with their respective QoS requirements. And F$^2$RAC is designed to properly determine the access regions and permission probabilities for enhancing the data packet delay while ensuring the voice packet dropping probability constraint. It mainly consists of the estimator with Pseudo-Bayesian algorithm and fuzzy logic controller with Sugeno-type of fuzzy rules. Simulation results prove that F$^2$RAC can guarantee QoS requirement of voice and provide the highest throughput efficiency and the smallest data packet delay amongst the different alternatives including PRMA［1］, IPRMA［2］, and SIR［3］.