• Journal of the Korean Institute of Navigation
• /
• v.9 no.1
• /
• pp.41-81
• /
• 1985

Tidal phenomenon can be utilized by the wise and cautious mariner to safely perform his duties as pilot and navigator. It can be either a help or hindrance to the mariner. The principle of MULDAE which expresses the determination of the state of the tide based upon knowledge of the lunar date and it has been used in Korea since ancient times. The folk method of calculation was essentially based on an unsystematic division of the lunar month, traditionally using the numbers 7 or 8. As the lunar cycle is complete in 15 days the tidal cycle should also correspondence closely to the lunar date. This paper represents the first scientific attempt to systematically investigate this unique traditional method of tidal calculation and contains a comparison of the MULDAE and ordinary (solar based) tide calculation methods. MULDAE was compared with the standard tide table for standard and island ports in Korea from 1982 to 1985. This study concluded that MULDAE was indeed an accurate adn reliable predictor of tidal activity. Furthermore, the number 6 was found to be the correct divisor upon which to base MULDAE calculations Also a formula expressing MULDAE as a function was discovered. This research show that MULDAE can be applied nationwide and is a reliable and easy way to predict tides based upon mean figures for certain ports and island A calender showing MULDAE is presented here for the first time. A clear relationship between the MULDAE method of calculating tides and the use of ordinary tide tables is proven.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.6
• /
• pp.863-870
• /
• 1993

A new methodology of multimedia data composition generated SRT(Synchronization Relation Tree) dynamically after user composing multimedia date by using high level user interface, and processes message passing protocols to adjust multimedia data temporal composition. In this paperl we propose SRT generating algorithm which transfer user defined timeline diagram to SRT dynamically. SRT generating algorithm is to use divide and conquer methodology and recurvise programming. And prove that it generates and type of multimedia date compositon to SRT.

• Journal of Industrial Technology
• /
• v.28 no.A
• /
• pp.51-61
• /
• 2008

In these days, domestic manufacturers are faced with managerial difficulties such as the increasing competition in their industry and the increasing power of customers. In this situation, they have to satisfy their customers with high quality of their products and meeting due date of their orders. Production of the order within due date is an important factor for improving enterprise competitiveness. The causes of occurrence of tardiness may be wrong product scheduling, unexpected events in field and so on, a way to minimize tardiness is use of alternative machines, overwork, outsourcing and etc.. In this study, we deal with a scheduling problem that can minimize tardiness using alternative machines. This paper provides a mathematical program and a heuristic method for job shop scheduling for minimizing tardiness with alternative machines. And a proposed heuristic method is verified comparing with optimal solution obtained by ILOG CPLEX.

• Architectural research
• /
• v.10 no.1
• /
• pp.41-48
• /
• 2008

Construction projects have frequently exceeded their schedule despite reliable estimates at the start of a project. This problem was attributed to unpredictable causes at the beginning and to shortage of proper tools to accurately predict project completion date. To supplement this difficulty, project managers need a comprehensive system that can be employed to monitor the progress of an ongoing project and to evaluate potential delay for achieving the goal on time. This paper proposed a progressive-based expert system for quantitative assessments of project delay at the early stages of the execution. Furthermore, the system is used to inspect the change of the uncertainty on completion date and its magnitude. The proposed expert system is helpful for furnishing project managers a warning signal as a project is going behind schedule and for tracking the changed uncertainty at a desired confidence level. The main objectives of this paper are to offer a new system to overcome the difficulties of conventional forecasting tools and to apply a construction project into the system to illustrate its effectiveness. This paper focuses on construction phase of project development and is intended for the use by project managers.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.42 no.1
• /
• pp.54-60
• /
• 2022

The planting date of corn for silage has been delayed because of spring drought and double cropping system in Korea. This experiment was conducted to evaluate agronomic characteristics, forage production and feed value of corn at April and May in 2019. Experimental design was a split-plot with three replications. Planting dates (12 April and 10 May) were designated to the main plot, and corn hybrids ('P0928', 'P1543' and 'P2088') to the subplot. The silking days of the early planting date (12 April) was 79 days and that of the late planting date (10 May) was 66 days (p<0.0001), however, there were no significant differences among the corn hybrids. Ear height of the late planting date was higher than that of the early planting (p<0.05), while there were no significant differences in plant height of corn. Insect resistance at the early planting was lower than that of late planting (p<0.05), however, lodging resistance was no significant difference at planting date. The rice black streaked virus (RBSDV) infection of early planting was 3.7% and that of late planting was 0.3% (p<0.001). Dry matter (DM) contents of stover, ear and whole plant had significant difference at planting date (p<0.05). And differences in ear percentages were observed among the corn hybrids (p<0.01). And ear percentages of early maturing corn ('P0928') was higher than for other hybrids. Ear percentage at the early planting date was higher than that at the late planting date (p<0.01). DM and total digestible nutrients (TDN) yields had significant difference at planting date, however, there were no significant differences among the corn hybrids. DM and TDN yields at the late planting (21,678 kg/ha and 14,878 kg/ha) were higher than those of the early planting (13,732 kg/ha and 9,830 kg/ha). Crude protein content at the early planting date was higher than that of the late planting. Acid detergent fiber content of the late planting was lower than that of the early planting date (p<0.01), while there were no significant neutral detergent fiber content difference among the corn tested. Calculated net energy for lactation (NE_L) and TDN at the early planting were higher than those of at the late planting (p<0.01). Results of this our study indicate that the late planting date (May) is better than early planting date (April) in forage yield and feed value of corn. Therefore, the delay of planting date by May was more suitable for use in cropping system.

• The Journal of Korean Society for Radiation Therapy
• /
• v.5 no.1
• /
• pp.47-56
• /
• 1992

This report presents the date obtained in a 1990 survery al radiation oncology identified by KSTRO. This study was done to find out the status of current use of the radation thrapy equipments, personnels, utilization of equipments and orther problems in the field of radiation oncology department in korea. Our discussion addresses the areas of regional imbalance in the distribution of megavolage units, buying and selecting the units, improving of quality in radiation treatments. There is increasing use of linear accelerators, simulators, treatment planning computers. The use of Cp-60 units has been prohressively decreasing. And slowly improving, numbers of physicians, physicists, and technologists when compared with the 1988. A total of 51 megavoltage units were identified, giving a ratio of 1.88 technologists/ megavoltage units. We treat average 23.0 patients by megavoltage units.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.20 no.2
• /
• pp.23-38
• /
• 1995

In manfacturing systems, to overcome the inherent complexities and uncertainties, due-dates are usually decided by some simple rules. This study proposes a computational procedure for estimating production lead time for computerized manufacturing systems. Based on the current system status stored in the computers, the procedure estimates production lead time for an incoming order. The result is more accurate than the ones produced by old rules, and yet the procedure is fast in computation speed enough to use in real time. Simulations are used to prove these.

• Korean journal of food and cookery science
• /
• v.5 no.2
• /
• pp.75-90
• /
• 1989

A survey on images and consumption for instant food for 419 housewives in Kyung-ki do were summarized as follows: 1) The thought of housewives takes 'convenient' as the best advantage in the image on instant food, generally speaking,'preference', 'hygienic concern' and 'eating frequently’ are moderate, while 'good for health' is shown with the lowest points. 2) The reasons why they take instant food are ascribed to the taste of the children by 63.6%, to 'convenient to cook' by 19.6%. 3) The reasons why they do not use instant food are attributed to 'bad for health’by 46.9% to 'too expensive' by 29.9%, and to 'doubtful in quality' by 16.3% 4) Instant noodle (Ramyun) and bread are consumed the most, and then consumption is shown from high to low in order of tomato-ketchup, ham, mayonnaise, instant liver and sausage. 5) Effects on purchasing instant food come from the date of manufacturing 43%, trade mark 24% the experience of previous use as high as 21.2%.

• Journal of Platform Technology
• /
• v.11 no.1
• /
• pp.52-59
• /
• 2023

The importance of spatio-temporal trajectories for contact tracing has increased due to the recent COVID-19 pandemic. Spatio-temporal trajectories store time and spatial data of moving objects. In this paper, I propose query processing for spatio-temporal trajectories of moving objects. The spatio-temporal trajectory model of moving objects has point type spatial data for storing locations and timestamp type temporal data for time. A trajectory query is a query to search for pairs of users who have been in close contact by boarding the same bus. To process the trajectory query, I use the Geolife dataset provided by Microsoft. The proposed trajectory query processing method divides trajectory data by date and checks whether users' trajectories were nearby for each date to generate information about contacts as the result.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.220-221
• /
• 2020

Strarting with Buyeong Apartment in Dongtan-2 disrict in 2017, collective complaints of residents are frequently occurring due to low quality problem such as improper construction and defects of apartment houses. Because of this, the Ministry of Land and Transport is preparing a comprehensive improvement scheme to improve the quality of Apartment Housing(AH), taking into account the continuing complaints from the residents of AH and the problem raised by the National Assembly. The basic profile of the improvement scheme is induce the tenants and experts to discover and point out defects that are repaired until the date of use inspection or due date. For this purpose, we suggested this defects management system linkaged by the preliminary inspection and quality inspection system for prospective occupants. In this context, this paper aims to suggest an effective likage method between the preliminary inspection of prospective residents and the quality inspection system implemented by local governments as an ordinance.