• Journal of the Korean Geotechnical Society
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• v.39 no.5
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• pp.27-40
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• 2023

A pile is a structural element that is used to transfer external loads from superstructures and has been widely utilized in construction fields all over the world. The method of installing a pile into the ground should be selected based on geotechnical conditions, location, site status, environmental factors, and construction costs, among others. It can be divided into two types: direct hammering and preboring. The direct hammering method installs a pile into the bearing layer, such as rock, using a few types of hammer, generating a considerable amount of pile driving-induced vibration. The vibration from pile driving influences adjacent structures and the ground; therefore, quantitatively investigating the effects of vibration is inevitably required. In this study, two-dimensional dynamic numerical modeling and analysis are performed using the finite difference method to investigate the influence on the adjacent slope, including temporary supporting system. Time-dependent loading induced by pile driving is estimated and used in the numerical analysis. Consequently, large surface displacement is estimated due to surface waves and less wave deflection, and refraction at the surface. The total displacement decreases with the increase of the distance from the source. However, lateral displacement at the top of the slope shows a larger value than vertical displacement, and the overall displacement tends to be concentrated near the face of the slope.

• Journal of The Korean Association For Science Education
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• v.27 no.4
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• pp.354-365
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• 2007

The purpose of this study was to understand the undergraduate students' response characteristics by their cognitive conflict levels and result predictions when they were confronted with the learning tasks of action & reaction and electric circuits. The 147 engineering college students who were enrolled at the introductory physics classes were selected as the subjects for this study. The students were grouped by cognitive levels and result predictions. First, in action and reaction task, the trend of suspecting experimental results and finding the reasons was dominant; however, in electric circuits, the trend of accepting the results was dominant. Second, the reasons for the responses on the subcategories of cognitive conflict were different by the level of cognitive conflict. The responses were influenced by students' preexisting knowledge, former experiences, learning habits, learning motivation, and epistemological beliefs, etc. The high conflict group recognized what they do not consider and was positive to reappraise their preconceptions, while the low conflict group showed the tendency of accepting the situation without doubt and low interest on learning physics. In conclusion, students responses showed differences in cognitive conflict levels, result predictions and presented conflict tasks. The research results, especially the response characteristics, suggest that more research on effective cognitive conflict strategies appropriate for different tasks and students' conflicts are necessary for effective physics teaching.

• Information Systems Review
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• v.20 no.4
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• pp.59-78
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• 2018

With the advent of the various device types and marketing communication, customer's search and purchase behavior have become more complex and segmented. However, extant research on multichannel marketing effects of the purchase funnel has not reflected the specific features of device User Interface (UI) and User Experience (UX). In this study, we analyzed the marketing channel effects of multi-device shoppers using a unique click stream dataset from global online retailers. We examined device types that activate online shopping and compared the differences between marketing channels that promote visits. In addition, we estimated the direct and indirect effects on visits and purchase revenue through customer's accumulated experience and channel conversions. The findings indicate that the same customer selects a different marketing channel according to the device selection. These results can help retailers gain a better understanding of customers' decision-making process in multi-marketing channel environment and devise the optimal strategy taking into account various device types. Our empirical analyses yield business implications based on the significant results from global big data analytics and contribute academically meaningful theoretical framework using an economic model. We also provide strategic insights attributed to the practical value of an online marketing manager.

• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.343-349
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• 2008

We have constructed a car-borne magnetic exploration system, in which a car drags a non-magnetic cart on which a magnetometer is installed. In the total magnetic field measured as a vectorial sum in this system, are included the magnetic field generated by the car itself. This magnetic field, doing the role of a magnetic noise, should be eliminated. For this purpose, we have set up a measurement condition to get the same effect as if we have put the car in one point and thereafter measured the magnetic field around it. In this case, if there is any magnetically anomalous body in the area, we can consider all the remaining magnetic field to have been generated by the car itself, once the geomagnetic field eliminated. We tried to invert the magnetic field considered to have been generated by the car and succeeded to derive the magnetic moment and the direction of the induced and remanent magnetic field of the car respectively. Once the magnetic moment and the direction of the induced and remanent magnetic field have been calculated, the magnetic field generated by them in specific points can be directly and analytically calculated. This result can be used in the future to eliminate the magnetic field generated by the car itself doing the role of a magnetic noise during the procedure of reduction of the measured magnetic exploration data by the car-borne magnetic exploration system.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.124-129
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• 2004

The composition of essential oils isolated from the aerial parts of Artemisia iwayomogi Kitamura and Artemisia capillaris Thunberg collected from two diffenent cultivation area, respectively, was analyzed by GC and GC-MS. Sixty components were identified in oils from A. iwayomogi. The major components of A. iwayomogi oil collected from one area (Sample A) were iso-pinocamphone (31.64%), 1,8-cineo1e (21.55%), ${\beta}-pinene$ (4.46%), pinocarvone (3.72%), myrtenal (3.42%) and trans-pinocarve1 (3.14%), and the major components of the oil from the other area (Sample B) were camphor (26.99%), 1,8-cineo1e (21.55%), ${\alpha}-terpineol$ (7.63%), borneol (4.10%), camphene (3.97%) and artemisia ketone (3.84%). Eighty components were identified in oils from A. capillaris. The major components were capillene $(26.01{\sim}30.31%)$, ${\beta}-pinene(8.55{\sim}18.38%)$, ${\beta}-caryophyllene(8.80{\sim}13.70%)$, ${\beta}-himachalene(1.67{\sim}5.57%)$, $cis,trans- {\alpha}-farnesene(2.10{\sim}7.38%)$ and germacrene D $(2.27{\sim}5.46%)$ and there was no difference in oil composition of A. capillaris between two cultivation area.

• Journal of Broadcast Engineering
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• v.18 no.3
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• pp.349-361
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• 2013

This paper proposes a fast face tracking method with only depth information. It is basically a template matching method, but it uses a early termination scheme and a sparse search scheme to reduce the execution time to solve the problem of a template matching method, large execution time. Also a refinement process with the neighboring pixels is incorporated to alleviate the tracking error. The depth change of the face being tracked is compensated by predicting the depth of the face and resizing the template. Also the search area is adjusted on the basis of the resized template. With home-made test sequences, the parameters to be used in face tracking are determined empirically. Then the proposed algorithm and the extracted parameters are applied to the other home-made test sequences and a MPEG multi-view test sequence. The experimental results showed that the average tracking error and the execution time for the home-made sequences by Kinect ($640{\times}480$) were about 3% and 2.45ms, while the MPEG test sequence ($1024{\times}768$) showed about 1% of tracking error and 7.46ms of execution time.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.51-57
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• 2003

Mitigation of fast neutron irradiation damage on reactor vessel and improvement of mechanical integrity are desired for the successful plant life-time extension. In this study, the performance of metallic hydride for this application is reviewed and compared. First, selected prospective metallic hydrides are evaluated by MCNP code and put into the attenuation test using Cf-252 neutron source. Since for the reactor application high moderation and reflection with no absorption are favored, Z factor is introduced for the evaluation. According to the Z value estimation $ZrD_2$ and $TiD_2$ are turned out to be the most favorable fast neutron shielding materials. More thorough evaluation by computer simulation and experimentally, will be followed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.6
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• pp.1-7
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• 2010

This paper presents a novel implementation on multimedia fingerprinting algorithm based on BCH (Bose-Chaudhuri-Hocquenghem) code. The evaluation is put in force the colluder detection to n-1. In the proposed algorit hm, the used collusion attacks adopt logical combinations (AND, OR and XOR) and average computing (Averaging). The fingerprinting code is generated as below step: 1. BIBD {7,4,1} code is generated with incidence matrix. 2. A new encoding method namely combines BIBD code with BCH code, these 2 kind codes are to be fingerprinting code by BCH encoding process. 3. The generated code in step 2, which would be fingerprinting code, that characteristic is similar BCH {15,7} code. 4. With the fingerprinting code in step 3, the collusion codebook is constructed for the colluder detection. Through an experiment, it confirmed that the ratio of colluder detection is 86.6% for AND collusion, 32.8% for OR collusion, 0% for XOR collusion and 66.4% for Averaging collusion respectively. And also, XOR collusion could not detect entirely colluder and on the other hand, AND and Averaging collusion could detect n-1 colluders and OR collusion could detect k colluders.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.69-75
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• 2013

This study is a fundamental research to test the applicability of powdered MSWI(Municipal Solid Waste Incinerator) ash melted slag as a seed Crystal for crystallization reaction. Powdered ash melted slag was melted at $1100^{\circ}C$ and ground to lesser than 0.35mm. According to the result of the tests, calcium, enough for crystallization reaction, was eluted from powdered ash melted slag. Moreover, sample(Phosphorus concentration is under 10 mg/L), more than 90% of Phosphorus can be removed. So we rectify the Phosphorus concentration to 100 mg/L. Alkalinity, being well known that it interferes crystallization reaction, effect was studied for synthetic solution(100 mg/L initial Phosphorus concentration, 50 mg/L calcium, pH 8, 1% powdered ash melted slag dosage). For this result, we know that Phosphorus removal is hindered by alkalinity. In addition, the effect of reaction temperature was performed at the same method. The reaction velocity was increased through raising the reaction temperature.

• Korean Journal of Cognitive Science
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• v.22 no.3
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• pp.255-270
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• 2011

The purpose of this study was to examine the effects of nonspecific and specific cue on decision making during situation awareness. Participants were 36 male college students who were randomly assigned to one of three groups: (1) nonspecific situation awareness, (2) specific situation awareness, and (3) a control group. Every participant was in the level 3-4.5 according to American National Tennis Level Program. Participants were asked to watch tennis single defence, single offence, double defence rally and when the screen stops, they were required to push the button(left, middle, or right) appropriate for the ball's direction to return as soon as possible. The experiment was designed to be analyzed for group(3)${\times}$condition(3)${\times}$area(7) using three-way ANOVA. The dependent variables were reaction time, accuracy rate, and amplitude and latency of P300. The result showed that the latency of the nonspecific situation awareness group and the specific situation awareness group was shorter and their amplitudes were higher than the control group. Fz, Cz, Pz were prominent among areas, and the single defence condition was more prominent than the single offence and the double defence condition. As a result of the study, it can be suggested that the information about situation awareness provided beforehand directly affects the brain's information processing. In addition, it shows that ERP can be a useful index for studying situation awareness.