• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2018.05a
• /
• pp.318-320
• /
• 2018

When a ship sails on sea, it may be influenced by the environmental disturbance such as wind, wave, sea surface temperature, etc. These affect on the ship's speed, fuel consumption, safety and operating performance. It is necessary to find the optimal weather route of a ship to avoid adverse weather conditions which can put the crews in serious danger or cause structural damage to the vessel, machinery, and equipment. This study introduced how to apply A* algorithm based on sea trial test data for determining the optimal ship routes. The path cost function was modelled as a function of minimum arrival time or minimum energy depending on the time of various environment conditions. The specially modelled path-cost function and the safety constraints were applied to the A* algorithm in order to find the optimal path of the ship. The comparison of ship performances estimated by real sea trial's path and estimated optimal route during the voyage of the ship was investigated. The result of this study can be used to create a schedule to ensure safe operation of the ship with short passage time or minimum energy. In addition, the result of this study can be integrated into an on-board decision supporting expert system and displayed in Electronic Chart Display and Information System (ECDIS) to provide all the useful information to ship master.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.5
• /
• pp.779-785
• /
• 2015

Recently, home energy management system (HEMS) for power consumption reduction has been widely used and studied. The HEMS performs electric power consumption control for the indoor electric device connected to the HEMS. However, a traditional HEMS is used for passive control method using some particular power saving devices. Disadvantages with this traditional HEMS is that these power saving devices should be newly installed to build HEMS environment instead of existing home appliances. Therefore, an HEMS, which performs with existing home appliances, is needed to prevent additional expenses due to the purchase of state-of-the-art devices. In this paper, an intelligent inference algorithm for EMS at home for non-power saving electronic equipment, called legacy devices, is proposed. The algorithm is based on the adaptive network fuzzy inference system (ANFIS) and has a subsystem that notifies retraining schedule to the ANFIS to increase the inference performance. This paper discusses the overview and the architecture of the system, especially in terms of the retraining schedule. In addition, the comparison results show that the proposed algorithm is more accurate than the classic ANFIS-based EMS system.

• Journal of Engineering Education Research
• /
• v.23 no.5
• /
• pp.68-75
• /
• 2020

In order to cultivate the talents acquired in the fourth industrial revolution, developed countries' government are actively engaged in the campaigns encouraging K-12 students to participate in the maker movement. Maker education is regarded as one possible solution based on high tech in the era of the 4th Industrial Revolution, and it is spreading widely along with STEM education. In South Korea, STEAM education was actively conducted nationwide, and since 2017, STEAM and maker education have been linked showing mutual development. However, compared to STEAM education linked to the curriculum, comparison and activity-based research on maker education for teenagers is still insufficient. Therefore, this study aimed to suggest implications for STEAM education and maker education by analyzing the motivation of Korean youth to participate in maker activities. The subjects of this study are high school students who participated in maker education programs in student community for the first time in Korea. In this study, students were classified into engineering-related career group and non-engineering-related career groups based on their career intentions, and the motivation and understanding of participation in maker activities were compared. As a result of the study, male students participated more in maker education community activities than female students, and the engineering-related career group had a higher intention to participate in games, outdoor activities, IT equipment, digital production, and electrical/electronic production activities than the non-engineering-related career group. In addition, in the fields of handicraft/art, home baking, installing, and horticultural agriculture, there was no difference in the intention of participate in the engineering-related career group and the non-engineering-related career group. It was found that the engineering-related career group believed that there was a strong relationship between the maker education community activity, career exploration and future career choice, while the non-engineering-related career group believed that the relationship is less strong. It was also found that the engineering-related career group was participating more actively in the maker activity than the other group.

• Korean Institute of Interior Design Journal
• /
• v.25 no.3
• /
• pp.70-81
• /
• 2016

Nowadays the preschool children spend much of the day playing indoors. Therefore, it needs the indoor environment that helps a variety of fun activities and physical development, and it requires the space configuration and playable furniture considering the emotional development for mental health. However, the furniture for fast growing preschoolers has not various types because the domestic furniture market for children is mostly baby beds and the furniture for the education of children. Therefore, this study presents the concepts and types of the playable furniture reflecting emotional design for preschool children's healthy emotion and suggests the most appropriate type of playable furniture considering play behavior by age. In this study, we investigated the physical, cognitive, social, emotional and linguistic development characteristics and play behavior of preschoolers, and derived the right type of playground equipment and furniture, and examined the types of playable furniture to help the emotional development. We derived the items to be checked for developing the playable furniture by age for emotional development, and classified preschoolers' playable furniture into the use of learning, relaxation and storage, and suggested its basic type focusing on the cases of various playable furniture developed at home and abroad. As a result, the playable furniture was divided into three types. The first is the self-play type making possible self amusement, the second is module built-up-type that consists of furniture and modules or units and creates various patterns and can be modified through the self-assembly and disassembly, and the third is IT game type grafting IT skills and a variety of electronic games to furniture. We sorted these types into three classes (1-3 years old, 4-5, 6-7) according to age and presented the type of play for each age, the play element and representative image that can be introduced to this furniture. In this study, we provided the basic design types of age-specific emotional playable furniture by analyzing these results.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.4
• /
• pp.1509-1514
• /
• 2011

The core of IT products, electronic components, especially the MLCC, chip inductors, chip Varistors and so on. In order to test the electrical characteristics of the chip using the Reno-pin contact test method has been used. In current chips, mass production of semiconductor manufacturing processes, high-speed production test for the chip speed up, precision is required. But Vibration displacement is a very short, so in order to overcome these shortcomings, the displacement amplification to design the structure has been actively studied. In this paper, a building structure with a flexible hinge was designed amplification instrument, semiconductor chip industry in the performance test and inspection equipment to measure the electrical characteristics of high speed linear actuators Reno-Pin using system was developed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.5
• /
• pp.49-55
• /
• 2016

To separate the CM and DM noise in the EMI generated in various electrical electronic systems, passive and active separators have been researched. These separators are an important part of an effective active EMI-filter. The passive separator has some advantages, in that it is easy to realize at a low price and its structure is very simple. However, its major drawback is that its accurate inductor realization and accurate core selection are very difficult. The active separator is smaller in size and more accurate, but its main drawback is that an op-amp which has a broad band frequency response is necessary, its cost is high, and a DC power circuit is required. This paper compares the characteristics of EMI filters which apply the existing passive separator and proposed active separator. It was concluded that an active separator is needed for expensive and accurate equipment, whereas a passive separator is sufficient for inexpensive and general purpose EMI filters.

• Resources Recycling
• /
• v.23 no.4
• /
• pp.58-68
• /
• 2014

The statistics showed that about 1 billion automobiles were registered and about 40million ELVs occurred on the world in 2010. So all advanced countries including EU had plan to increase the ELVs recycling rate up to 95% of total by 2015. The Korean government also established a target for raising up to 95% of ELVs recycling rate according to 'Act on the Resource Circulation of Electrical and Electronic Equipment and Vehicles'. Before being satisfied with the requirement of recycling of ELVs however, the problem is issued on the scraps of plastic and non-ferrous metals which are now being abandoned and reclaimed with no adequate reuse. Therefore, as a part of preceding investigation on the present state of ELVs recycling in the world, this preliminary investigation study was carried out focusing on the state of EU's disposal and management regulations of ELVs and SLF/ASR including the world trend of disposal and management regulations of ELVs and SLF/ASR.

• Journal of the Korean Institute of Gas
• /
• v.24 no.1
• /
• pp.33-40
• /
• 2020

Chiller systems which have better temperature stability than Direction expansion coils are often used as condensing units in HVAC systems for offshore plants. Large capacity compressors and electronic expansion valves in chiller systems are mostly imported, and the size of a chiller system depends on heat exchangers such as evaporators and condensers which are locally produced. Due to limited space in the offshore plants, shipyards are demanding manufacturers to make equipment compact. In this paper, a shell & tube heat exchanger, which is used as an evaporator in the conventional flooded chiller system, is replaced by a newly developed compact plate & shell heat exchanger. The main development process of the plate & shell heat exchanger is introduced, and its performances were experimentally evaluated with a real flooded chiller system, and the results are presented.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.9
• /
• pp.2319-2325
• /
• 2009

This paper compared the output limits value of the Korean weak electric field strength wireless device in the 58kHz band with the standard values of foreign countries. Through this, the study confirmed that the Korean regulation was lower by about 50dB than those of the USA or Europe. In order to prove this, the study measured outputs by entrusting the 58kHz EAS system to two measuring companies. As a result of these measurements, electric field strengths were shown to be $112dB{\mu}V/m$ and $08dB{\mu}V/m$ respectively, and these values were confirmed to exceed the current Korean standard of $102.7dB{\mu}V/m$. Accordingly, it is deemed necessary to review the specifications of the Korean standard in the 58kHz band.

• Journal of the Korean Magnetic Resonance Society
• /
• v.17 no.2
• /
• pp.98-104
• /
• 2013

The ERETIC (Electronic REference To access In vivo Concentrations)2 method is a new qNMR experimental technique to measure analytes based on the signal of the reference compound without additional hardware equipment. In this study, ERETIC2 method was validated, and we sought to identify whether it would be possible to apply this method to a specific compound analysis of metabolites in plant. The $90^{\circ}$ pulse value (P1) and spin-lattice relaxation time ($T_1$) of each compound were measured for ERETIC2. The $9^1H$ of 3-(trimethylsilyl) propionic-2,2,3,3-$d_4$ acid (TSP) was used as a reference peak for ERETIC 2, and then, a suitable solvent and pulse sequence for each compound were selected. Under the NOESY-presat sequence, the relative accuracy error for quantitative analyses of primary metabolites was within the range of 5%, with the exception of glucose, which showed ${\geq}$ 55% error due to saturation. It showed excellent results for the quantification of glucose by using a $30^{\circ}$ pulse sequence, which did not suppress the water peak. In addition, the quantitative accuracy for secondary metabolites was extremely accurate, with an error ${\leq}$5% when considering the purity of the standard sample. The ERETIC2 method showed outstanding linearity, precision, and accuracy.