• Journal of Distribution Science
• /
• v.19 no.3
• /
• pp.61-70
• /
• 2021

Purpose: This paper reviews the attitudes of consumers related to the consumption crisis response strategy (i.e., defensive vs. receptive) that companies implement during crises. Research design, data, and methodology: We discuss the interaction between the crisis response strategy and the consumption crisis type (i.e., corporate ability vs. corporate social responsibility). We used SAS ver. 9.4 software to analyze the results. We applied a 2 × 2 intergroup experimental design to our sample of subjects, who were undergraduate and graduate students at a university in Seoul, South Korea. The three experimental variables considered were the entity's risk response strategy, the crisis type, and public relations strategy. The experiments were conducted by presenting a hypothetical scenario to eight groups. Prior to this experiment, five preliminary surveys were conducted to determine the three variables just mentioned. Preliminary surveys were conducted on the basis of these criteria. For eight selected product lines, 320 undergraduates were required to enter the product lines that are frequently used in the assessment center up to the fourth priority. Results: Analysis of variance revealed that experiments related to crisis response strategy, type of enterprise crisis, and type of public relations message were successful. Conclusions: Our results verify the impact of different types of social initiatives on distribution marketplaces.

• Journal of Auto-vehicle Safety Association
• /
• v.14 no.3
• /
• pp.35-40
• /
• 2022

In this study, the driving performances of elderly who's age is over 65 were evaluated. The driving simulation was conducted using a compact driving simulation (CDS) and the simulation scenarios were developed from actual roads by replicating geometry of skewed intersection and traffic control devices located in Jungnang-gu, Seoul, Korea. 27 elderly drivers and 10 non-elderly drivers were recruited and participated on the virtual turning right and going straight driving experiment of CDS. Virtual driving data of driving time, speed, distance, acceleration and deceleration speeds, brake power, and steering wheel rotation angle were recorded and analyzed. Generally, elderly driver took more times to pass through the skewed intersection road and showed lower approaching speed as much as 40% and 25% in case of turning right and going straight scenarios respectively. The speed deviation at skewed intersection road between elderly and non-elderly driver is expected to cause frequent lane changes and overtaking.

• Journal of Broadcast Engineering
• /
• v.26 no.7
• /
• pp.868-876
• /
• 2021

Deploying deep neural network model training performs remarkable performance in the fields of Object detection and Instance segmentation. To train these models, features are first extracted from the input image using a backbone network. The extracted features can be reused by various tasks. Research has been actively conducted to serve various tasks by using these learned features. In this process, standardization discussions about encoding, decoding, and transmission methods are proceeding actively. In this scenario, it is necessary to analyze the response characteristics of features against various distortions that may occur in the data transmission or data compression process. In this paper, experiment was conducted to inject various distortions into the feature in the object recognition task. And analyze the mAP (mean Average Precision) metric between the predicted value output from the neural network and the target value as the intensity of various distortions was increased. Experiments have shown that features are more robust to distortion than images. And this points out that using the feature as transmission means can prevent the loss of information against the various distortions during data transmission and compression process.

• The Journal of Korea Robotics Society
• /
• v.17 no.3
• /
• pp.373-380
• /
• 2022

This paper considers a method of fast correspondence matching for iterative closest point (ICP) algorithm. In robotics, the ICP algorithm and its variants have been widely used for pose estimation by finding the translation and rotation that best align two point clouds. In computational perspectives, the main difficulty is to find the correspondence point on the reference point cloud to each observed point. Jump-table-based correspondence matching is one of the methods for reducing computation time. This paper proposes a method that corrects errors in an existing jump-table-based correspondence matching algorithm. The criterion activating the use of jump-table is modified so that the correspondence matching can be applied to the situations, such as point-cloud registration problems with highly curved surfaces, for which the existing correspondence-matching method is non-applicable. For demonstration, both hardware and simulation experiments are performed. In a hardware experiment using Hokuyo-10LX LiDAR sensor, our new algorithm shows 100% correspondence matching accuracy and 88% decrease in computation time. Using the F1TENTH simulator, the proposed algorithm is tested for an autonomous driving scenario with 2D range-bearing point cloud data and also shows 100% correspondence matching accuracy.

• The Journal of Korea Robotics Society
• /
• v.17 no.3
• /
• pp.264-272
• /
• 2022

Human-robot cooperative tasks are increasingly required in our daily life with the development of robotics and artificial intelligence technology. Interactive reinforcement learning strategies suggest that robots learn task by receiving feedback from an experienced human trainer during a training process. However, most of the previous studies on Interactive reinforcement learning have required an extra feedback input device such as a mouse or keyboard in addition to robot itself, and the scenario where a robot can interactively learn a task with human have been also limited to virtual environment. To solve these limitations, this paper studies training strategies of robot that learn table balancing tasks interactively using deep reinforcement learning with human's facial expression feedback. In the proposed system, the robot learns a cooperative table balancing task using Deep Q-Network (DQN), which is a deep reinforcement learning technique, with human facial emotion expression feedback. As a result of the experiment, the proposed system achieved a high optimal policy convergence rate of up to 83.3% in training and successful assumption rate of up to 91.6% in testing, showing improved performance compared to the model without human facial expression feedback.

• Journal of Distribution Science
• /
• v.21 no.6
• /
• pp.39-49
• /
• 2023

Purpose: This paper aims to investigate the influence of different methods of distributing sweepstakes (i.e., whether consumers choose to enter into the sweepstakes themselves or they are given the sweepstake ticket by default) on the effectiveness of the sweepstakes promotion (i.e., interest in the sweepstakes and intention to participate in the sweepstakes). Research design, data and methodology: The paper verifies this effect through three experimental studies: an online experiment using a sweepstakes promotion scenario at a department store, an online SNS sweepstakes promotion event, and a face-to-face card lottery game. Results: Participants belonging the group that chose sweepstakes tickets by themselves showed higher interest and intention to participate in the sweepstakes than those who were given the sweepstakes ticket by default. Furthermore, the group that chose the sweepstakes card thought it had a higher probability of winning than the group given the sweepstakes card. Conclusions: This paper shows a way to enhance the promotional effect of sweepstakes in the retail stores, without incurring additional costs, by approaching from sweepstakes design from the psychological perspective of the consumer. The study also sheds new light on the effect of sense of control manipulation using choice behavior in the promotional context.

• International Journal of Internet, Broadcasting and Communication
• /
• v.15 no.2
• /
• pp.60-72
• /
• 2023

The purpose of this study is to measure the change in evacuation time at high schools according to the change in hallway width using an evacuation simulation program and to analyze the result of such change. In order to measure the evacuation time according to the change in the hallway width according to the 「Rules on the Standards for Evacuation and Fire Protection Structures of Buildings」 and to analyze the change in evacuation time resulted from the increase in the number of occupants, a scenario was constructed by applying the 「performance-oriented design method and standard for firefighting facilities, etc.」. As a result of the experiment, it was found that the evacuation time was the shortest when the width of the hallway was the widest, which was 3m. On the other hand, the evacuation time took the longest at 1.8m, which was the width of the second narrowest hallway. For the safety of high school students who spend a lot of time at school, it is necessary to secure a wide hallway width when building a new school or to provide periodic safety education in the case of an existing school whose hallways are considered narrow.

• Journal of Auto-vehicle Safety Association
• /
• v.15 no.2
• /
• pp.6-12
• /
• 2023

For the commercialization and standardization of autonomous vehicles, demand for rigorous safety criteria has been increased over the world. In Korea, the number of extraordinary service permission for automated vehicles has risen since Hyundai Motor Company got its initial license in March 2016. Nevertheless, licensing standards and evaluation factors are still insufficient for operating on public roadways. To assure driving safety, it is significant to verify whether or not the vehicle's decision is similar to human driving. This paper validates the safety of the autonomous vehicle by drawing scenario-based comparisons between manual driving and autonomous driving. In consideration of real traffic situations and safety priority, seven scenarios were chosen and classified into basic and advanced scenarios. All scenarios and safety factors are constructed based on existing ADAS requirements and investigated via a computer simulation and actual experiment. The input data was collected by an experimental vehicle test on the SNU FMTC test track located at Siheung. Then the offline simulation was conducted to verify the output was appropriate and comparable to the manual driving data.

• Nuclear Engineering and Technology
• /
• v.55 no.5
• /
• pp.1604-1615
• /
• 2023

In an open-pool type research reactor with a downward forced flow in the core, pipes can be under sub-atmospheric pressure because of the large pressure drop at the reactor core in the atmospheric pool. Sub-atmospheric pressure can result in air inflow into the pipe from the pressure difference between the atmosphere and the inside of the pipe, which in a postulated pipe break scenario can lead to the breakdown of the cooling pump. In this study, a plant-scale experiment was conducted to study air inflow in large piping systems by considering the actual operational conditions of an advanced research reactor. The air inflow rate was measured, and the entrained air was visualized to investigate the behavior of air inflow and flow regime depending on the pipe break size. In addition, the developed drift-flux model for a large vertical pipe with a diameter of 600 mm was compared with other correlations. The flow regime transition in a large vertical pipe under downward flow was also studied using the newly developed drift-flux model. Consequently, the characteristics of two-phase flow in a large vertical pipe were found to differ from those in small vertical pipes where liquid recirculation was not dominant.

• The Bulletin of The Korean Astronomical Society
• /
• v.45 no.1
• /
• pp.34.1-34.1
• /
• 2020

The recent discovery of diffuse dwarf galaxies that are deficient in dark matter appears to challenge the current paradigm of structure formation in our Universe. We describe the numerical experiments to determine if the so-called dark matter deficient galaxies (DMDGs) could be produced when two gas-rich, dwarf-sized galaxies collide with a high relative velocity of ~ 300km/s. Using idealized high-resolution simulations with both mesh-based and particle-based gravito-hydrodynamics codes, we find that DMDGs can form as high-velocity galaxy collisions separate dark matter from the warm disk gas which subsequently is compressed by shock and tidal interaction to form stars. Then using a large simulated universe ILLUSTRISTNG, we discover a number of high-velocity galaxy collision events in which DMDGs are expected to form. However, we did not find evidence that these types of collisions actually produced DMDGs in the ILLUSTRISTNG100-1 run. We argue that the resolution of the numerical experiment is critical to realize the "collision-induced" DMDG formation scenario. Our results demonstrate one of many routes in which galaxies could form with unconventional dark matter fractions.