• Title/Summary/Keyword: Master-slave

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On the Improvement of Accuracy of Position Fix By Loran C to Compute with Micro Computer (전산처리에 의한 로오란 C의 선위정도 개선에 관하여)

  • 안장영
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.20 no.2
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    • pp.112-121
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    • 1984
  • This paper is compared the simulation tables by the general propagation velocity and the calculated propagation velocities with distances and times to take to be transmitted Loran C wave from master station to slave stations, with Loran C tables, and compared the accuracy of position fixes by the simulation to them by Loran C table with the time differences of 9970 chain to be measured in the south coast of Korea, and by the simulation with the time differences of 5970 chain to be measured at definite position to them. The results obtained are as follows; 1. the simulation tables by the calculated propagation velocities is nearer to Loran C tables than it by the general propagation velocity. 2. The ranges of total errors of the simulation positions by the general propagation velocity and the calculated propagation velocities to the position fixies of Loran C table with the time differences of 9970 chain to be measured in the south coast of Korea are 0.2-0.7 miles, 0.01-0.1 miles, and the mean values of them are 0.46 miles and standard deviations of time are 0.1 miles, 0.03 miles respectively. 3. Mean value of total errors of the simulation position by the calculated propagation velocities to the definite position with the time difference of 5970 chain is 0.2miles and is reduced 0.1-0.2 miles than it by the general propagation velocity.

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A study on enhanced D-InSAR technique Considering Spatial and Temporal Coherence (공간적·시간적 긴밀도를 고려한 개선된 D-InSAR 기법에 관한 연구)

  • Lee, Won Eung;Yoon, Hong Sik;Youm, Min Kyo;Kim, Han Bual
    • Journal of Korean Society for Geospatial Information Science
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    • v.25 no.2
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    • pp.67-74
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    • 2017
  • The D-InSAR is a technique for precisely measuring the subsidence of subsidence using difference of two SAR images. In order to calculate the subsidence using D-InSAR, a high coherence between master image and the slave image is essential. Since the existing D-InSAR method calculates the displacement based on the total coherence, the accuracy of the subsidence is lowered when the coherence map contains mountains or bare-land. In order to solve this problem, in this study, a point having a temporal coherence and spatial coherence of 0.7 or more was extracted to form TIN, and the subsidence was calculated based on this TIN. In addition, we compared the existing D-InSAR technique with the new D-InSAR technique considering spatial and temporal coherence. As a result, the new D-InSAR technique showed smaller standard deviation, relative variance, variation coefficient and quadrature deviation than the existing D-InSAR technique. It is also easy to grasp the trend of the subsidence.

A study on improvement of ISO/IEC 29157 MAC protocol (ISO/IEC 29157 표준 MAC 프로토콜 개선 연구)

  • Cha, Bong-Sang;Jeong, Eui-Hoon;Jeon, Gwangil;Seo, Dae-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.5
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    • pp.17-26
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    • 2013
  • ISO/IEC 29157 originally developed in the Republic of Korea and is based on commercially available PicoCast v1.0. ISO/IEC JTC1 SC6 was registered by the international standard on May 2010. A single platform for a variety of applications and media formats to support development objectives were. ISO/IEC 29157 based wireless networks, ie, Pico-net to master node periodically transmit sync signal is synchronized to the number of slave nodes have the communications structure. Pico-net also supports a variety of network topologies and direct communication between nodes(single-hop communication) and QoS is guaranteed. But Pico-net network structure has the following problems. Loss of communication problems due to mobile nodes, resulting in limitations of node mobility and wireless network operation range of conventional wireless networks operating range less than 1/4 was reduced to the problem. In this paper, a possible solution to the problems mentioned is proposed, using multi-hop communication technology and sync signal transmission technology between nodes.

Development of Modeling Technique for Prediction of Driving Force and Kinetic Resistance of Agricultural Forklift (농업용 포크리프트의 구동력 및 운동저항 예측을 위한 모델링 기법 개발)

  • Jo, Jae-hyun;Kim, Jun-tae;Jeong, Jin-hyoung;Chang, Young-yoon;Park, Won-yeop;Lee, Sang-sik
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.3
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    • pp.299-305
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    • 2019
  • This study was initiated to solve the difficulties of aged and female workers in agriculture society due to aging and demise of young people. In the case of the conventional elevated lift, the risk of exposure to uneven road or work environment, not the difficulty of professional qualification and operation, and the risk of exposure to the uneven road or working environment, were also studied based on previous researches so that women could easily and efficiently perform productive agriculture. First, the simulation was carried out through the prediction model of traction performance using the object of agricultural forklift, and the soil of the Kimhae city in Gyeongnam (34.125kPa, internal friction angle 35.294deg, external friction angle 13.620deg, Adhesion force 5.750 kPa, average cone index 0-15 cm cl, 1001.8 kPa). In the case of the forklift for simulation, the driving force and the kinetic resistance prediction modeling of the agricultural electric forklift are modeled. Based on this model, the motor control drive adopts the 1232E model, which is a drive dedicated to AC motor, and divides the two drivers into master and slave And the model for the simulation was designed to control motor drive, hydraulic drive, and various outputs on the main PCB. The simulation model is undergoing continuous simulation, modification and supplementation. Based on this research, we will continue research for development of safer and more efficient agricultural electric forklift.

The Haenam Yoon's the 8th jonbu(종부) Gwangju Lee's family management in Korean letter of Joseon era (한글편지에 나타난 해남윤씨가 8대 종부 광주이씨의 가문경영)

  • Lee, hyun-ju
    • (The)Study of the Eastern Classic
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    • no.73
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    • pp.385-414
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    • 2018
  • In this article, the women as the subject of the family management in the 19th century cataclysm, In particular, I tried to reconstruct the specific life course of a woman who has a status as a jongbu(종부) in the Korean language through the Hangul letter. The Haenam Yoon's the 8th jongbu(종부) Gwangju Lee attempted to find her own unique identity, not the male-centered social order she had learned. Because she had to live a life outside the traditional environment of traditional society because her husband died at the beginning of her marriage. She perceived herself as an independent subject that she had to find and maintain. When Gwangju Lee married and came to the family of Haenam Yun, the economic power of jong-ga(종가) was much inclined. This economic difficulty was caused by the conflict with the slaves and the decrease of tallage(地代) to the change of the slavery system which was the social flow at that time. And uncles of her husband's intervention made the economic situation of the family more difficult. She established her position as a jongbu(종부) and used the right of Adoption option(입후권) of the jongbu(종부) to establish the impoverished family. She chose adoption from distant relatives who were not children of her husband's uncles. Therefore, I was free from her husband uncle's interests. She also believed that it was most important to take control of the economic interests of her family in order to secure her authority as a jongbu(종부). She believed that she had to exercise her economic rights in order to bring slave labor, which is the most important means of sustaining the domestic economy at the time, In the absence of her husband, she established her family in the social upheaval of the nineteenth century, and took her place as a master of a family, not just a family name.

A Comparison of the Metanarrative and East Timor's Local Narrative in Indonesia under the Suharto's Regime (인도네시아의 메타내러티브와 동티모르의 로칼내러티브의 서술구조 비교)

  • Song, Seung-Won
    • Journal of International Area Studies (JIAS)
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    • v.15 no.1
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    • pp.155-180
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    • 2011
  • This paper aims at comparing the metanarrative and East Timor's local narrative in Indonesia during the Suharto's regime. Although these history writings have different political goals, the patterns of writings are ironically similar. Both of the history writings show strong nationalistic history writing patterns. Yet, in the writings, these histories place different interpretations on the historical events. In the metanarrative, local dynamics are seen through the diagrams of the nation and nationhood. This narrative finds the roots of the "ethnie" from some kingdoms in Java and Sumatra. These kingdoms, which throve based on the Hindu-Buddhist culture, achieved a territorial unity to a degree, covering some parts of Java and Sumatra. The glorious past disappeared with the advent of the colonial rule. The metanarrative then emphasizes the unity of the ethnic groups in the archipelago, which fiercely resisted against the colonial exploitation and oppression. By this, these ethnic groups were defined as "the masses," the collective identity, which had a same goal to achieve the national independence. In addition, some local histories, which took positive attitudes toward the European forces, were simply left out from the metanarrative. All the separatist movements taking place in the republic were also described as the anti-unifying forces. On the other hand, the goal of the history-writing in East Timor was to enhance the sense of nationalism and create the perception of the "East Timorese." The fundamental aim was the separation from Indonesia. In the narrative, the nationalist politicians overcame the problem of the non-existence of any memories of the glorious past with the awakening of the idea of "the imagined gloriousness of the past if there was no colonial rule." In addition, the narrative overemphasizes the memory of the colonial rule for 450 years under the Portuguese rule in order to stress the fact that it was the colony of Portugal, not of the Netherlands. Finally, the narrative shows how the East Timorese collectively fell to the status of slaves. By this, the political leaders of East Timor evoked the notion that it was recolonized by Indonesia, under which the East Timorese were demoted to the status of slaves. This notion of "slave-master" relationship then became the motives for the independence struggles in East Timor.