• Journal of Korea Multimedia Society
• /
• v.13 no.11
• /
• pp.1715-1727
• /
• 2010

Although a hand haptic interaction which provides direct and natural sensation is the most natural way of interacting with VR environment, the hand haptic interaction has still limitations with respect to the complexity of articulated hand and related hardware capabilities. Particularly, virtual assembly simulation which refers to the verification process of digital mockup in product development lifecycle is one of the most challenging topics in virtual reality applications. However, hand haptic interaction is considered as a big obstacle, because difficulty initial grasping and non-dextrous manipulation remain as unsolved problems. In this paper, we propose that common hand haptic interactions involves two separate stages with different aspects. We present the hand haptic interaction method enables us to stably grasp a virtual object at initial grasping and delicately manipulate an object at task operating by one's intention. Therefore, proposed method provides the robustness using grasping quality and dextrous manipulation using physically simulation. We conducted experiments to evaluate the effectiveness of our proposed method under different display environments -monoscopic and stereoscopic. From 2-way ANOVA test, we show that the proposed method satisfies two aspects of hand haptic interaction. Finally, we demonstrated an actual application of various assembly simulation for relatively complex models.

• Spatial Information Research
• /
• v.22 no.2
• /
• pp.53-62
• /
• 2014

The floor field model is the micro pedestrian model based on a cellular automata for modeling pedestrian movement in the interior space using the static and dynamic floor field. It regards a form of pedestrian as square but the actual pedestrian's shape and size are similar to ellipsoid or rectangle. Because of this, we are difficult to give a rotation effect to pedestrians and there is a limit to reflect an impact of clogging and jamming. Also, this model is not able to reflect an impact of a posture and visibility effectively in the pedestrian movement. In this study, we suggest the improved pedestrian model incorporating the actual shape and size of pedestrian. The pedestrian's shape is defined not square but rectangle which is close to the actual body size of Korean. Also, we define the model which is able to represent the impact of clogging and jamming between pedestrians by adding the pedestrian's posture. We develop the simulator for testing the suggested model and study the difference between two models by comparing a number of effects. As a result, we could confirm solving the problem with dynamic value in the existed model and reflecting the panic effect in evacuation situation.

• Journal of The Korean Association For Science Education
• /
• v.37 no.6
• /
• pp.1063-1073
• /
• 2017

This study analyzed the difficulties elementary school students have in role-playing analogy activities for concept learning of heat transfer. Eleven fifth graders were given an orientation class on role-playing analogy activity, a class for concept learning of heat transfer as presented in a textbook, and then they performed the role-playing analogy activity with concepts of heat transfer. After the classes, researchers investigated the difficulties students encountered through questionnaires and interviews. The following are results of the research: Difficulties that students faced in role-playing analogy activity can be classified into five types. First, students encountered difficulties in expressing the analogy. The students who had difficulties in expressing the analogy focused on expressions outside the science concepts or lacked understanding of the science concepts. They also had difficulties in expressing the analogy because they lacked the expressiveness of analogy or abilities in mapping errors. They had difficulties in expressing the planned role-playing analogy in a narrow space. Second, students also experienced difficulties in performing activities due to lack of understanding on activities or lack of experience. Third, students experienced difficulties in selecting roles because they preferred the specific role or unwanted the specific roles. Fourth, the members of group experienced difficulties in group activities because they did not concentrate on activities, failed to perform roles, or showed attitudes of an onlooker. Fifth, they experienced difficulties in communications due to unilateral communication, conflicts of opinions, and lack of opinions.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.9 s.351
• /
• pp.49-59
• /
• 2006

DAS(Driver Assistance Systems) support the driver's decision making to increase safety and comfort by issuing the naming signals or even exert the active control in case of dangerous conditions. Most previous research and products intend to offer only a single warning service like the lane departure warning, collision warning, lane change assistance, etc. Although these functions elevate the driving safety and convenience to a certain degree, New type of DAS will be developed to integrate all the important functions with an efficient HMI (Human-Machine Interface) framework for various driving conditions. We propose an all-around sensing based on the integrated DAS that can also remove the blind spots using 2 cameras and 8 sonars, recognize the driving environment by lane and vehicle detection, construct a novel birds-eye HMI for easy comprehension. it can give proper warning in case of imminent danger.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.5
• /
• pp.527-534
• /
• 2019

Several types of mathematical analysis methods are used for port waterway risk assessment based on marine traffic volume. In Korea, a marine traffic congestion model that standardizes the size of the vessels passing through the port waterway is applied to evaluate the risk of the waterway. For example, when marine traffic congestion is high, risk situations such as collisions are likely to occur. However, a scientific review is required to determine if there is a correlation between high density of maritime traffic and a high risk of waterway incidents. In this study, IWRAP Mk2(IALA official recommendation evaluation model) and a marine traffic congestion model were used to analyze the correlation between port waterway risk and marine traffic congestion in the same area. As a result, the linear function of R2 was calculated as 0.943 and it was determined to be significant. The Pearson correlation coefficient was calculated as 0.971, indicating a strong positive correlation. It was confirmed that the port waterway risk and the marine traffic congestion have a strong correlation due to the influence of the common input variables of each model. It is expected that these results will be used in the development of advanced models for the prediction of port waterway risk assessment.

• (The)Study of the Eastern Classic
• /
• no.66
• /
• pp.163-191
• /
• 2017

In the Book 1 starting with the narrative, metaphor, prediction, implication and paradox shows the relationship and its significance of Lee Hye-ran and Ho Hong-mae. Especially, these techniques show the key and topic of this work of 'jealousy' and its conflicting 'unjealousy' being materialized and its background are being provided, and they play narrative roles of showing in advance the numerous incidents that occur within the relationship between the main characters. Especially, jealousy and unjealousy are shown through the two main female characters: the unjealousy is connected to with Lee Hye-ran to show the extreme womanhood to lead the narrative. Meanwhile, the jealousy that occurs from the affection and obsession towards one person, it disables Ho Hong-mae from having rational judgment, and maleficence from the jealousy cannot be stopped. Eventually, in the process of finishing the narrative, the jealousy is regarded as the issue of the family, and the cause of the jealousy is emphasized the man not being faithful to the family. Therefore, the solutions to the issues occurred from the jealousy are shown explicitly that it is in the proper management of the family by the man. Therefore, the narrative of is progressed while jealousy and unjealousy conflict, and in the process of repenting the character that shows the perfect womanhood realized in the fiction world and the most radical jealousy through such womanhood, this novel can be regarded as showing the ethical lesson.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.4
• /
• pp.474-482
• /
• 2021

An average of two to three typhoons that occur in the Philippines or Taiwan pass through Korea each year owing to the influence of the geographical location and western winds. Because Jinhae Bay is known as Korea's representative typhoon refuge, it is filled with ships during typhoons and later becomes saturated with ships anchored to the surrounding routes. If a strong wind drags an anchored ship, a collision accident may occur because of the short distance between the ships. Therefore, a systematic anchoring safety management of Jinhae Bay is required. In this study, the minimum wind speeds of a dragging anchor based on the water depths of Jinhae Bay anchorages were investigated. When 7-9 shackles were given, the minimum wind speeds were 48-63, 46-61, and 39-54 knots at depths of 20, 35, and 50 m, respectively. As the water depth increased, the length of the cable laid on the sea bed became shorter than 5 m owing to the external force, and the minimum wind speed showed a significant difference of 4-8 knots. In addition, ships with high holding power anchors (AC-14 type) had higher minimum wind speeds than ships with conventional anchors (ASS type). Finally, it was confirmed that at a depth of 50 m, dragging easily occurred even when a high holding power anchor was applied.

• Journal of International Area Studies (JIAS)
• /
• v.14 no.3
• /
• pp.421-440
• /
• 2010

This paper examines middle powers' ODA policy in the post cold war era and discusses its implication for Korean aid strategy. Middle powers' ODA has been more successful than that of super powers in promoting donors' positive images and in stimulating recipient countries' development. Middle powers tend to pursue multilateral solutions to international problems often by taking a mediator role, and their ODA policies set them apart from the great players in international politics. Middle powers' ODA is primarily aimed at reducing poverty and protecting human rights in least developed countries where humanitarian aid needs the most rather than promoting donors' interests. Also, middle powers have provided bilateral untied aid in the sectors of food aid and emergency relief and steadily devoted about 0.7% of their gross national income to ODA. Meanwhile, Korea as an emerging middle power and a new donor has been implementing its own aid strategy under the name of the Korean development model since the post cold war period. The Korean ODA was not successful in building donors' positive images by simply following the short term strategies of US and Japan. Yet, its ODA policy has been quite effective in sustaining local development by creating specific niches in which the country can specialize in. In specific, Korea has focused on developing the sectors of information and communication technology and industry energy in recipients' countries by maximizing its comparative advantage.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.4
• /
• pp.338-347
• /
• 2023

Jinhae Bay, characterized by frequent runaway ships and strong winds during typhoon attacks, poses a high risk of maritime accidents such as ship collisions and groundings. This study aims to determine a safe separation distance between ships in the Jinhae Bay anchorage, considering the unique environmental characteristics of the Korean sea area. Analysis revealed that an average of 100-200 ships anchor in the typhoon avoidance area in Jinhae Bay during typhoon attacks, with approximately 70% of ships experiencing anchor dragging owing to strong external forces exceeding 25 m/s wind speeds. In this study, we analyzed and presented the separation distances between ships during anchoring operations based on domestic and international design standards, separation distances between ships used as actual typhoon shelters in Jinhae Bay, and appropriate safe distances for ships drifting under strong external forces. The analysis indicated that considering the minimum criteria based on the design standards and emergency response time, a minimum safe distance of approximately 400-900 m was required. In cases where ample space was available, the separation distance was recommended to be set between 700 to 900 m. The findings of this study are anticipated to contribute to the development of guidelines for establishing safe separation distances between ships seeking refuge from typhoons in Jinhae Bay in the future.

• Journal of Advanced Navigation Technology
• /
• v.27 no.6
• /
• pp.710-715
• /
• 2023

Urbanization brings many challenges such as traffic, housing, and environment. To solve these problems, researchers are working on new transportation systems like urban air mobility (UAM). UAM aircraft should fly safely without burdening the existing air traffic system in the early stage of low-density operation. The airspace should also be managed and operated efficiently. Therefore it is important to make urban air traffic predictable by using corridors and collecting data on low-density operations in the early stage. For this purpose various simulations are needed before operation to create scenarios that estimate potential collisions between UAM aircraft and to evaluate the risks of aircraft spacing, loss of separation (LoS), and near mid air collision (NMAC). This paper focuses on identifying the requirements and considerations for setting separation standards for urban air traffic based on the results of studies.