• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.4
• /
• pp.777-785
• /
• 2016

IM(Instant Messenger) chatting service can carry user's various information including life style, geographical position, and psychology & crime history and thus forensic analysis on the IM service is desirable. But, forensic analysis for KakaoTalk's chatting service is not well studied yet. For this reason, we study KakaoTalk's forensic analysis focusing on chatting service. This paper first details a general method of IM forensics investigating the previous articles about IM forensics although there are not many articles. Second, we discuss methodologies for IM forensics wherein we present analysis of table structure and method for reconstruction of chatting message. These result in the basic element of forensic tools of KakaoTalk chatting message. Last, we compare artifacts of KakaoTalk with that of WhatsApp. We conclude that these applications are, at least, different in that table structures and the ways to reconstruct chatting messages are not same and therefore digital evidences or artifacts are not same and somewhat distinct.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.1
• /
• pp.23-33
• /
• 2018

In the general manual feeder of an LED lighting assembly system, many workers are needed to supply parts to the main conveyor. The automatic feeder for modern automation lighting assembly systems consists of a completely automated feeding system and a magazine system that supplies the parts automatically. A standardized LED panel and diffusion cover is stacked in the cartridge of the magazine system. The structural safety of the automatic feeding system with regard to handling the load from the panels and covers stored in the cartridge should be guaranteed. LED convergency lighting modules are assembled using two LED panels and one diffusion cover in an automatic feeder. In this study, the structural safety and fatigue life of the automatic feeder and magazine were analyzed by considering the load generated in the automatically assembled LED convergency lighting system. In addition, the dynamic behavior of each auto-feeding system and magazine delivery system was visualized, and the working process was evaluated via dynamic simulation using a virtual engineering method. A tack time table for automatic feeding systems was derived by developing a virtual prototype.

• Current Research on Agriculture and Life Sciences
• /
• v.32 no.3
• /
• pp.165-169
• /
• 2014

This study assessed the economic feasibility of an automatic egg washer. Based on various cost benefit analysis methods, including the net present value (NPV), internal rate of return (IRR) and benefit cost ratio (B/C Ratio), the automatic egg washer was confirmed to have economic feasibility. The NPVs were 38,565,991 won at 5% discount rate and 32,013,916 won at 10% discount rate, respectively. The IRRs were 1.325 at 5% discount rate and 1.299 at 10% discount rate, respectively. Finally, the B/C ratios were 1.726 at 5% discount rate and 1.699 at 10% discount rate.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.5
• /
• pp.1798-1813
• /
• 2021

This paper proposes a positive experience design approach for Internet of Things (IoT) intelligent products to improve users' subjective well-being in the fields of artificial intelligence and big data. First, the authors selected six target users and taking the Xiaomi IoT intelligent products for the research objects and conducted a thorough observation on how the target users used IoT intelligent products in their own homes over two weeks via a home-visiting interview, group diary, and focus group. Second, they constructed an individual activities table for the participants' IoT intelligent product experience using a hierarchical task analysis (HTA). Third, two researchers sorted out the sub-tasks of happiness in the HTA table. Finally, the authors found the positive experience design approach of IoT intelligent products. The positive experience design approach of IoT intelligent products is proposed from focusing on the personal pleasure experience to individual life meaningful design and group social relationship design, including individual pleasure experience, personal goal realization, group needs satisfaction and the harmony of group relations. The paper uses the two design examples of an interactive kettle and a harmonious chair to further discuss the feasibility of the design approach. In the era of big data, it is helpful for designers to use this design approach to improve the users' sense of sustainable pleasure, achievement perception of their future goal realization, and the well-being of the group's social relationships.

• Nuclear Engineering and Technology
• /
• v.55 no.11
• /
• pp.4252-4265
• /
• 2023

In the case of nuclear power plants near end of their design life, a reassessment of the performance of safetyrelated equipment may be necessary to determine whether to shut down or extend the operation of the power plant. Therefore, it is necessary to evaluate the level of performance decline due to degradation. Electrical cabinets, including MCC and switchgear, are representative safety-related equipment. Several studies have assessed the degradation and seismic performance of nuclear power plant equipment. Most of those researches are limited to individual components due to the size of safety-related equipment and test equipment. However, only a few studies assessed the degradation performance of electrical cabinets. The equipment of various nuclear power plants is anchored to concrete foundations, and crack in concrete foundations is one of the most representative of degradation that could be visually confirmed. However, it is difficult to find a study for analysis through testing the effect of cracks in concrete foundations on the response of electrical cabinet internal equipment fixed by anchors. In this study, using a simple cabinet model considering cast-in-place anchor in uncracked and cracked concretes, a tri-axial shaking table tests were performed and the seismic behavior were observed.

• Current Research on Agriculture and Life Sciences
• /
• v.32 no.4
• /
• pp.231-235
• /
• 2014

This study performed a benefit cost analysis of an automatic eggshell crack detection system. Based on various cost benefit analysis methods, including the net present value (NPV), internal rate of return (IRR), and benefit cost ratio (B/C Ratio), the automatic eggshell crack detection system was confirmed to have economic validity. The NPVs were 175,035,645 won at a 5% discount rate and 129,082,393 won at a 10% discount rate. Plus, the IRRs were 0.686 at a 5% discount rate and 0.660 at a 10% discount rate. Finally, the B/C ratios were 1.981 at a 5% discount rate and 1.900 at a 10% discount rate.

• Journal of Life Science
• /
• v.19 no.9
• /
• pp.1299-1303
• /
• 2009

The purpose of this study was to analyse the gait characteristics of stroke patients walking on a Zebris system, through quantitative three-dimensional biomechanical analysis. They underwent a continuous rehabilitation training program (RTP). A comparison was made between 3 month and 6 month RTP participants. Their ages were between 60 and 65. The data were analyzed by t-test. The result of comparative analysis of the two groups can be summarized as below. Temporal-spatial data, sagittal plane angular kinematics data, and peak ground reaction force and max pressure data showed that there were no significant differences between the 3 month RTP group and the 6month RTP group (Table 2, Table3, Table 4). It can be suggested that patients with hemiplegia after stroke can improve their walking function through continuous RTP participation.

• Korean Journal of Applied Biomechanics
• /
• v.20 no.2
• /
• pp.155-165
• /
• 2010

The purpose of this study was to analyze kinematic quantitative factors required of a forehand counter drive in table tennis through 3-D analysis. Four national table tennis players participated in this study. The mean of elapsed time for total drive motion was $1.009{\pm}0.23\;s$. At the phase of impact B1 was the fastest as 0.075 s. This may affect efficiency in the initial velocity and spin of the ball by making a powerful counter drive. The pattern of center of mass showed that it moved back and returned to where it was then moved forward. At the back swing, lower stance made wide base of support and a stronger and safer stance. It may help increasing the ball spin. Angle of the elbow was extended up to $110.75{\pm}1.25^{\circ}$ at the back swing and the angle decreased by $93.75{\pm}3.51^{\circ}$ at impact. Decreased rotation range of swinging arm increased linear velocity of racket-head and impulse on the ball. Eventually it led more spin to the ball and maximized the ball speed. Angle of knee joint decreased from ready position to back swing, then increased from the moment of the impact and decreased at the follow thorough. The velocity of racket-head was the fastest at impact of phase 2. Horizontal velocity was $7796.5{\pm}362\;mm/s$ and vertical velocity was $4589.4{\pm}298.4\;mm/s$ at the moment. It may help increase the speed and spin of the ball in a moment. The means of each ground reaction force result showed maximum at the back swing(E2) except A2. Vertical ground reaction force means suggest that all males and females showed maximum vertical power(E2), The maximum power of means was $499.7{\pm}38.8\;N$ for male players and $519.5{\pm}136.7\;N$ for female players.

• Korean Journal of Agricultural Science
• /
• v.33 no.2
• /
• pp.179-193
• /
• 2006

Technical efficiency of semiforcing watermelon growers is 0.8248 on average, and distributed between 0.6744 and 0.9268. The result showed that semiforcing watermelon growers had by 18% of technical inefficiency and could be assumed that increasing technical efficiency could induce watermelon production more increase. Consequently, if growers' technical efficiency were improved while other environments were constant, watermelon production could be increased. Following the results from the inefficiency effect model, all assumption coefficient such as growers age etc, are significant at 10% level. Estimate of dispersion parameter ${\gamma}$ is 0.89, which confirms those differences between practical output and frontier output were derived from the technical efficiencies among growers. Differences of production system between high and low level growers in production efficiency were showed at side altitude, ventilation and heat-retaining in section of facilities and automation, soil test and calcium application in section of environment management, transplant preparation and duration of pollination in section of crop management and shipment place, sorting degree and management record analysis in section of business management respectively. As a result of analyzing consulting data by using standard diagnosis table of watermelon cultivation under structure which cultivated on semi-forced watermelon growers, gap between high and low level growers was 7.0 points in facility automation section, 7.1 points in environment section, 8.8 points in crop management section and 13.6 points in business management section, respectively, which were the biggest one among them. In case of excluding information-related items from the evaluation index of business management section, changes of business achievement are to occur. Therefore, it is recommended for us to review the standard diagnostic table of watermelon cultivation under structure by dividing evaluation index of management section into management and information.

• Korean journal of food and cookery science
• /
• v.20 no.1
• /
• pp.100-111
• /
• 2004

The purpose of this study was to investigate the status of current nutrition labeling on the packaging of the processed foods that provide consumers with a reliable and consistent source of information, which has been considered as a useful aid for food selection and a potent educational tool for nutrition in daily life. The 2,160 processed foods purchased at the supermarket on September, 2002, were divided by food category issued from the 2002 food codes and assessed in the terms of the nutrition composition labeling and nutrition claims. Nutrition composition labeling was found on 356 of the 2160 processed foods items. Milk and dairy products had 49.7％ of nutrition composition labeling, which was the largest number among the food category. Tables were most frequently used as the type of nutrition composition labeling (79.8％). Nutrition composition including many different ways of expression, such as a table of nutrition composition, indication of nutrition composition, analysis table of nutrition composition and comparative table of nutrition composition, made frequent use of nutrition composition labeling titles (78.7％). The various unit of measures were use in the nutrition labeling of the processed foods, per l00g or 100$m\ell$ was the highest (44.6％) under the currently practiced nutrition labeling. The correct labeling standard with nutrient content and ％ RDA except energy, was used on 47.8％ of labels, and those with only liability indication nutrient and liability indication nutrients plus discretion indication nutrients were 25.3 and 22.5％ respectively. The processed foods with nutrition claims were 8.0％ (172 items). Nutrition claims were divided in two ways: nutrient content claims and nutrient comparative claims. The most frequently used claims were contained in the former (44.4％) and more or plus in the latter case (16.3％). Ca was the most popular item as a nutrition claim nutrient (50.6％).