• Cement
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• s.54
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• pp.59-74
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• 1974

AIS 지역 국가들의 시멘트 소비는 1970년에 14.1백만톤에 달했으며 1985년에는 44.2백만톤에 달할 것으로 예측된다. 1970년의 생산 능력은 18.4백만톤으로 이것은 수요를 훨씬 상회하는 것이다. 이같은 과잉 생산 능력 상태는 1981년 후부터는 과잉 수요 현상으로 전환하게 될 것으로 예상 된다. 1985년 AIS지역 전체로 볼 때 공급 부족량이 약 11.5백만톤에 이를 것인 바 그 대부분은 한국 $\cdot$ 베트남 $\cdot$ 인도네시아에서 부족하게 될 것이다. 한국의 시멘트 산업은 AIS지역 국가들 중에서 생산 기술면이나 생산 효율면에서 가장 앞서 가고 있다. 그러나 한국에서의 생산 시설 확장은 이 지역의 공급 부족량 해결에 기여는 하지 못할 것이며 오직 자국내 공급난 해결을 하는데 그칠 것이다. 이 보고서에서는 두 개의 상이한 계획안이 검토되었는데 이것은 지역내 협력효과와 같은 경제적인면에 초점을 두었다. 비교적 지역 협력에 기여할 것으로 보이는 두 개의 안은 AIS지역내의 2개 국가에 시멘트 공장을 건설하는 것으로서 인도네시아에 세우는 년산 1백만톤 규모의 단일공장과 타이에 세우는 년산 1백만톤 규모의 3개 공장이 바로 그것이다. 인도네시아에 세우는 공장은 인도네시아 시장의 수요 및 나아가 1985년에 Sri Lanka에서 일어날 과잉 수요를 메우게 될 것이다. 타이에 세우게 될 공장은 자국의 시멘트를 조달하고 메콩강과 연해 있는 3개국 수요를 충당하게 될 것이다. 이것은 1개의 공장을 건설하고 후에 그 생산 능력을 3배가하는 방법으로 이 3개의 공장이 완성된다면 이것은 또한 몇가지 경제성을 얻게 될 것이다. 인도네시아와 타이의 이 계획은 1985년에야 완성될 것인데 건설 기간은 약 28내지 30개월이 소요될 것으로 추산된다. 한편 이 지역의 시멘트 판매가격을 톤당 22달러로 볼 때 생산비에 포함된 총회수율, 즉 추정소득과 총투자 사이의 관계에서 산출한 이상 2개 사업의 총회수율은 12.1 $\%$로 추산된다. 총부가가치는 인도네시아가 10.7백만달러, 타이가 23.9백만달러로서 합계 34.6백만달러로 추산된다. 이것은 총투자액인 166.0백만달러에 대하여 4.8의 총자본투자효율을 나타내는 것이다. 이 사업은 이 지역외에서의 시멘트 수입시와 비교하면 73.8백만달러의 외화를 절약하는 셈이 되며 이 외에도 약 1,740명의 고용 증대를 가져 올 수 있을 것이다. 시멘트 운송비는 생산원가와 세계시장 가격과의 사이에서 생기는 마진보다 더 비싸다. 이와 같은 사실은 시멘트가 지역 협력에 적합한 품목이 못된다는 것을 의미한다. 이것을 해결하기 위해서는 현재 세계 시멘트 시장가격을 상회하는 선에서 가격협정을 맺는 것이 이 지역 시멘트 공업 육성책의 하나로 필요 불가결한 실정이다.

• Korean Journal of Remote Sensing
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• v.38 no.5_2
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• pp.737-746
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• 2022

Utilizing weather independent SAR images along with machine learning based object detector is effective in robust vessel monitoring. While conventional SAR images often applied amplitude data from Single Look Complex, exploitation of polarimetric parameters acquired from multiple polarimetric SAR images was yet to be implemented to vessel detection utilizing machine learning. Hence, this study used four polarimetric parameters (H, p₁, DoP, DPRVI) retrieved from eigen-decomposition and two backscattering coefficients (γ₀, _VV, γ₀, _VH) from radiometric calibration; six bands in total were respectively exploited from 52 Sentinel-1 SAR images, accompanied by vessel training data extracted from AIS information which corresponds to acquisition time span of the SAR image. Evaluating different cases of combination, the use of polarimetric indexes along with amplitude values derived enhanced vessel detection performances than that of utilizing amplitude values exclusively.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.32-33
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• 2013

In the past, the scenario of VTS simulator was made by instructor's manual operation using waypoint definition of target ship. but in this study, we use automatic scenario creation technology with AIS data and Port-MIS data. The created VTS simaulator scenario also can be modified, added, and saved by instructor's manual operation. VTS simulator display target ship on the Electronic Navigation Chart based on S-57 format. A instructor can easily open this scenario and start, pause, stop operation wirth VTS simulator. A new modification also can be applied immediately to current scenario and can be saved new scenario file. VTS simulator using this technology can create many scenarios for a specific purpose and can be easily used for various application fields.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.231-238
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• 2023

The position of a light buoy is always flexible due to the influence of external forces such as tides and wind. The position can be checked through AIS (Automatic Identification System) or RTU (Remote Terminal Unit) for AtoN. As a result of analyzing the position data for the last five years (2017-2021) of a light buoy, the average position error was 15.4%. It is necessary to detect position error data and obtain refined position data to prevent navigation safety accidents and management. This study aimed to detect position error data and obtain refined position data by DBSCAN Clustering position data obtained through AIS or RTU for AtoN. For this purpose, 21 position data of Gunsan Port No. 1 light buoy where RTU was installed among western waters with the most position errors were DBSCAN clustered using Python library. The minPts required for DBSCAN Clustering applied the value commonly used for two-dimensional data. Epsilon was calculated and its value was applied using the k-NN (nearest neighbor) algorithm. As a result of DBSCAN Clustering, position error data that did not satisfy minPts and epsilon were detected and refined position data were acquired. This study can be used as asic data for obtaining reliable position data of a light buoy installed with AIS or RTU for AtoN. It is expected to be of great help in preventing navigation safety accidents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.440-451
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• 2013

Recently, researches of technology and standardization for maritime safety are proceeding internationally. In particular, some technologies and strategies for e-Navigation have been developed and the necessity of development of next generation VTS (Vessel Traffic Service) has been raised in Korea. In order to construct user oriented VTS system for domestic environment, VTS operators are asked for their requirements related to developing VTS and the opinions should be reflected in the VTS. So in this paper, we collect the requirements from fifteen VTS centers in the country and we also analyze them. Furthermore, we propose an ASM (Application Specific Messages) service, which was not supported by current VTS, and we verify the proposed ASM through AIS (Automatic Identification System) system and simulation terminal for maritime safety.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.313-320
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• 2022

The light buoy installed on the sea is always flexible, because it is affected by the weather as well as passing vessels. The position of the light buoy can be cached through the AtoN AIS (Automatic Identification System) and RTU (Remote Terminal Unit). This study analyzed the position data of the light buoys for the last five years (2017-2021), as well as the distribution of the light buoys within the maximum separated position. As a result, there was a basic error of 17.9% in the position data. Additionally, the separated position error of 197 light buoys to be analyzed was 70.64%, and the AtoN RTU was worse than the AtoN AIS by equipment. On the other hand, as a result of the plotting the position data of the light buoy, it was classified into four types. The most common percussion center type, the percussion center dichotomous type in which the position is divided into two zones based on the chimney, the central movement type with a fluctuating center, and the drag type, in which the position is deviated from the center for a certain period. Except for Type-1, the type was determined according to the position at which the light buoy was installed. This study is the first to analyze the position data of the light buoy, and it is expected that it will contribute to the improvement of the quality of the position data of the light buoy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.483-490
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• 2013

In this study, we analyzed AIS measured data for ten days by selecting the four main ports with many ships arriving in the national ports. The peak time congestion of the main ports, calculated by survey research, was about 3.8-5.7 times higher than the hourly average congestion. This is very different from the results of the advanced research, evaluating the marine traffic congestion of the Ulsan main port based on the existing Port-MIS statistical data, which showed a peak time congestion of about 1.7 times higher than the hourly average. This identifies the problem of distorting the traffic characteristics of the current passage. Therefore, in order to evaluate marine traffic congestion, it would be more appropriate to calculate it based on survey research, rather than Port-MIS statistical data.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.659-664
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• 1996

The amount and characteristics of pectin in the albedo and flavedo layers of the citrus peels, and those of the pulp were investigated. Alcohol insoluble solid(AIS) content was the highest in albedo layer(18.1%), and the lowest in pulp(5.7%). The pulp and the albedo layer showed a potential pectin sources as containing pectins of 40.5% and 35.2% of the total polysaccharides of the pulp and the albedo layer, respectively. Total pectin contents were about 30% of the AIS and showed comparatively constant values among the byproducts. Hydrochloric acid soluble pectin contents were the hightest in the flavedo layer, 14.0%, and the lowest in the pulp, 4.4%. Over 90% of the total pectin could be extracted after 60min with 0.05N HCI at $85^{\circ}C.$ Microwave treatment reduced the extraction time significantly ; a comparable extraction yield was acquired after 10min with microwave treatment. The degree of esterification of the extracted pectin also increased with microwave treatment. Neutral sugars in the hydrolysate of the pectin were rhamnose, arabinose, galactose, glucose and xylose. No differences in molecular weight distribution of the pectin were found between the albedo and flavedo layers. Pectin of the pulp showed different molecular weight distribution from that of the peels.

• Korean Journal of Human Ecology
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• v.6 no.2
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• pp.57-65
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• 2003

To investigate quality characteristics of kimchi prepared for the winter around Chonnam area, home made kimchi samples collected from 22 area, and they were stored at -1${\pm}$1$^{\circ}C$. The results were as follows : The pH and acidity of kimchi samples were 4.75 and 0.84%. respectively. Salt concentration was 3.50% and in Redox potential measurement, Eh value was -134.08mV. Ascorbic acid and reducing sugar contents were 10.l8mg% and 13.25mg%, respectively, In color measurement, L value was 52.29 and a and b values were 19.68 and 27.69, respectively. Total viable count was 5.5${\times}$10$\^$6/ and lactic acid bacteria count and yeast were 4.6${\times}$10$\^$5/ and 8.8${\times}$10$\^$5/. respectively. Properties of hardness of kimchi measured instrumentally was 9.26kgf. Alcohol insoluble solids(AIS) content was 5.53% and hot water soluble pectin(HWSP) content and sodium hexametaphosphate soluble pectin(NaSP) content were 17.35% and 29.65%, respectively, also hydrochloric acid soluble pectin(HClSP) content was 53.0%.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.249-254
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• 2014

Recent advancement of USN technology has lent itself to the evolving communication technology for implantable devices in the field of medical service. The wireless transmission section for communication between implantable medical devices and patients is a cause of concern over invasion of privacy, resulting from external attackers' hacking and thus leakage of private medical information. In addition, any attempt to manipulate patients' medical information could end up in serious medical issues. The present study proposes an authentication protocol safe against intruders' attacks when RFID/USN technology is applied to implantable medical devices. Being safe against spoofing, information exposure and eavesdropping attacks, the proposed protocol is based on hash-function operation and adopts session keys and random numbers to prevent re-encryption. This paper verifies the security of the proposed protocol using the formal verification tool, Casper/FDR.