• Journal of Veterinary Science
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• v.24 no.1
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• pp.4.1-4.16
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• 2023

Background: In vitro culture of preantral follicles is a promising technology for fertility preservation. Objectives: This study aims to investigate an optimized three-dimensional (3D) fetal bovine serum (FBS)-free preantral follicle culture system having a simple and easy operation. Methods: The isolated follicles from mouse ovaries were randomly divided in an ultra-low attachment 96-well plates supplement with FBS or bovine serum albumin (BSA) culture or encapsulated with an alginate supplement with FBS or BSA culture. Meanwhile, estradiol (E₂) concentration was assessed through enzyme-linked immunosorbent assay of culture supernatants. The diameter of follicular growth was measured, and the lumen of the follicle was photographed. Spindle microtubules of oocytes were detected via immunofluorescence. The ability of oocytes to fertilize was assessed using in vitro fertilization. Results: The diameters were larger for the growing secondary follicles cultured in ultra-low attachment 96-well plates than in the alginate gel on days 6, 8, and 10 (p < 0.05). Meanwhile, the E2 concentration in the BSA-supplemented medium was significantly higher in the alginate gel than in the other three groups on days 6 and 8 (p < 0.05), and the oocytes in the FBS-free system could complete meiosis and fertilization in vitro. Conclusions: The present study furnishes insights into the mature oocytes obtained from the 3D culture of the preantral follicle by using ultra-low attachment 96-well plate with an FBS-free system in vitro and supports the clinical practices to achieve competent, mature oocytes for in vitro fertilization.

• Journal of the Korea Society for Simulation
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• v.15 no.3
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• pp.61-67
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• 2006

This paper provides a systematic way of integrating human intelligence and autonomous precision of robots to achieve the highest possible performance of a cooperating robot system. Adjustable autonomy, which deals with the combination of human and robotic skills, has the potential to bridge the gap which leaves many tasks suited to robotics beyond the reach of existing technology. Especially we will show that relevant human assistance or intervention will increase system performance by improving the exception handling capability, simplifying autonomous operation, and boosting speed and reliability. To support the usefulness of our scheme, a series of experiments were conducted with three cooperating robots which work together to dock both ends of a long suspended beam into stanchions.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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• pp.153-164
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• 2019

This paper presents the development of an end-to-end numerical simulator for signal design of the next generation global navigation satellite system (GNSS). The GNSS services are an essential element of modern human life, becoming a core part of national infra-structure. Several countries are developing or modernizing their own positioning and timing system as their demand, and South Korea is also planning to develop a Korean Positioning System (KPS) based on its own technology, with the aim of operation in 2034. The developed simulator consists of three main units such as a signal generator, a channel unit, and a receiver. The signal generator is constructed based on the actual navigation satellite payload model. For channels, a simple Gaussian channel and land mobile satellite (LMS) multipath channel environments are implemented. A software receiver approach based on a commercial GNSS receiver model is employed. Through the simulator proposed in this paper, it is possible to simulate the entire transceiver chain process from signal generation to receiver processing including channel effect. Finally, numerical simulation results for a simple example scenario is analyzed. The use of the numerical signal simulator in this paper will be ideally suited to design a new navigation signal for the upcoming KPS by reducing the research and development efforts, tremendously.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.171-176
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• 2023

What we have in common worldwide today is economic difficulties due to high inflation and uncertainty in the financial industry. The root cause of this is the war between Russia and Ukraine. The war between Russia and Ukraine is not simply a war between two countries. The United States and the European Union are providing military aid such as missiles to Ukraine, and Russia is attacking Ukraine by introducing UAVs (unmanned aerial vehicles) from Iran. A prominent weapon in this Russia-Ukraine war is the UAVs used in Russia. It is predicted that the form of war using UAVs will gradually expand in the future based on stealth. In addition, UAVs will continue to be used due to the fact that they can cause serious damage to the other country without harming their own lives, and because they have good cost-effectiveness. In this study, UAVs based on autonomous driving were studied. The target countries of the study include the United States, the European Union, China, and Iran, and the UAVs used in these countries have characteristics that can represent the world. In this study, the main specifications of major UAVs in use in major countries were investigated. In addition, the future technology and development direction were described through specifications and characteristics of UAVs currently in operation in major countries.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.4
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• pp.364-371
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• 2016

The analysis on the international safety management code (ISM Code) and case of foreign national safety management for fishing vessel was conducted to serve as a basic data on the introduction of safety management system (SMS) for a deep-sea fishing vessel in Korea. As a result, Maritime New Zealand (MNZ) has managed operations of SMS in the maritime rules according to the Maritime Transport Act since 1994. MNZ underwent a safe ship management (SSM), which includes elements applied to shipping companies, ship and verification of the ISM Code for ships, except ISM Code application since 1998. In 2014 the introduction of the advanced maritime operator safety system (MOSS) superior to the SSM by MNZ was promoted actively switch and enforcement. Meanwhile, the safe operation manual of Japanese fishing vessel includes large part of the contents of the ISM Code, and voluntary implementation to fit the realities of the fishing vessel. The law application of SMS for a deep-sea fishing vessel after the newly establishment of the Ocean Industry Development Act to SMS would be advantageous to the schematic management, supervision, maintenance and application and, in 2016 from the implementation of maritime safety supervisor for a deep-sea fishing vessel that the management and supervision through the fishing vessel will be the efficient operation. The configuration of the safety management system in a deep-sea fishing vessel should be included as an element of ISM Code. The introduction of such a system is gradually applicable, such as nationality overseas vessel case study of the ISM Code, and vessels that are excluded from the application will be implemented as autonomous as Japan. The results are expected to contribute to sustainable development in the ocean industry safety culture spread throughout the ocean industry through the enhancement of safety fishing competency and safety management responsibility of fisher.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.567-572
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• 2019

In this paper, we propose an algorithm to perform convolution, pooling, and ReLU operations in CNN using binary image and binary kernel. It decomposes 256 gray-scale images into 8 bit planes and uses a binary kernel consisting of -1 and 1. The convolution operation of binary image and binary kernel is performed by addition and subtraction. Logically, it is a binary operation algorithm using the XNOR and comparator. ReLU and pooling operations are performed by using XNOR and OR logic operations, respectively. Through the experiments to verify the usefulness of the proposed algorithm, We confirm that the CNN operation can be performed by converting it to binary logic operation. It is an algorithm that can implement deep running even in a system with weak computing power. It can be applied to a variety of embedded systems such as smart phones, intelligent CCTV, IoT system, and autonomous car.

• Ocean and Polar Research
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• v.35 no.2
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• pp.107-121
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• 2013

The underwater glider is an autonomous vehicle that can glide through the ocean interior by using a pair of wings attached to its body and can move up and down through the water column by changing its buoyancy. As of now, there are three widely-used gliders, namely, the Spray that was co-developed by Scripps Oceanographic Institution and Woods Hole Oceanographic Institution, the Slocum produced by the Webb Research Cooperation, and the Seaglider that was produced by the University of Washington. In this paper, I will introduce these three gliders and discuss the principles and procedures related to glider operation as well as the application and extendability of modern physical and bio-geochemical sensors to gliders. My experiences in developing a glider for measuring ocean turbulence and testing it 7 times during 12 days are shared in this paper. On the basis of my experiences and knowledge, different kinds of aspects that should be considered for successful glider operation are discussed. In addition, a suggestion is made as to what would be the ideal way to operate underwater gliders in the East/Japan Sea. At the end, the current status of active glider operation teams is presented and the efforts to proceed toward future gliders are briefly introduced.

• Journal of Mechanical Science and Technology
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• v.19 no.6
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• pp.1290-1303
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• 2005

In this research, a remote control system has been developed and implemented, which combines autonomous obstacle avoidance in real-time with force-reflective tele-operation. A tele-operated mobile robot is controlled by a local two-degrees-of-freedom force-reflective joystick that a human operator holds while he is monitoring the screen. In the system, the force-reflective joystick transforms the relation between a mobile robot and the environment to the operator as a virtual force which is generated in the form of a new collision vector and reflected to the operator. This reflected force makes the tele-operation of a mobile robot safe from collision in an uncertain and obstacle-cluttered remote environment. A mobile robot controlled by a local operator usually takes pictures of remote environments and sends the images back to the operator over the Internet. Because of limitations of communication bandwidth and the narrow view-angles of the camera, the operator cannot observe shadow regions and curved spaces frequently. To overcome this problem, a new form of virtual force is generated along the collision vector according to both distance and approaching velocity between an obstacle and the mobile robot, which is obtained from ultrasonic sensors. This virtual force is transferred back to the two-degrees-of-freedom master joystick over the Internet to enable a human operator to feel the geometrical relation between the mobile robot and the obstacle. It is demonstrated by experiments that this haptic reflection improves the performance of a tele-operated mobile robot significantly.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2952-2965
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• 2023

Advanced reactors, such as Small Modular Reactors or existing Nuclear Power Plants, often use Field Programmable Gate Array (FPGA) based controllers in new Instrumentation and Control (I&C) system architectures or as an alternative to existing analog-based I&C systems. Compared to CPU-based Programmable Logic Controllers (PLCs), FPGAs offer better overall performance. However, programming functions on FPGAs can be challenging due to the requirement for a hardware description language that does not explicitly support the operation of real numbers. This study aims to implement the Reactor Trip (RT) functions of the existing analog-based Reactor Protection System (RPS) using FPGAs. The RT equations for Overtemperature delta Temperature and Overpower delta Temperature involve dynamic compensators expressed with the Laplace transform variable, 's', which is not directly supported by FPGAs. To address this issue, the trip equations with the Laplace variable in the continuous-time domain are transformed to the discrete-time domain using the Z-transform. Additionally, a new operation based on a relative value for the equation range is introduced for the handling of real numbers in the RT functions. The proposed approach can be utilized for upgrading the existing analog-based RPS as well as digitalizing control systems in advanced reactor systems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.137-138
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• 2019

The International Maritime Organization (IMO) adopted the Circular 101 (MSC / Circ. 1604) as an interim guidelines for MASS trials at the 101st Maritime Safety Committee. This guideline will be used as a guideline for the sea trials of Maritime Autonomous Surface Ships(MASS) in the future and will be used by government authorities and stake-holders to secure infrastructure for MASS safety, environmental protection and remote operation. The purpose of this study is to analyze the Interim Guidelines for MASS Trials adopted by IMO and to clearly classify the responsibilities and obligations of governments of stake-holders, and to present the main points of risk management necessary for maritime test operation from the perspective of human factors.