• Journal of Dental Rehabilitation and Applied Science
• /
• v.20 no.2
• /
• pp.83-94
• /
• 2004

The purpose of this study was to compare the distributing pattern of stress according to the types of occlusal load on the finite element models of the splinted implant prostheses. The finite element model was designed with the parallel placement of two fixtures ($4.0mm{\times}11.5mm$) on mandibular first and second molars. The cemented crowns for mandibular first and second molars were made. Three-dimensional finite element model was created with the components of the implant, surrounding bone and cemented crowns. Two types of occlusal load, the point load and the surface load within 0.5 mm radius circle, were applied to the finite element models with 200N magnitude in axial(along the long axis of the implant and oblique(angulation of $30^{\circ}$ to the long axis) directions perpendicular to cuspal incline. Loads were positioned from the center of central fossa and to distance of 2 mm and 4 mm apart from the center of central fossa. Von-Mises stresses were recorded and compared in the fixtures and sections. The results were as following : 1. Under axial loading at the central fossa, the stress was distributed along the fixture except for the apical portion, not relative to both point & surface contacts. 2. With offset distance increasing, the highest stresses were concentrated in the neck portion of the fixture. 3. The maximum von Mises stress under the oblique load was greater than that under the axial load. 4. Under the oblique load, the highest stress were concentrated in the buccal side and lingual neck portion of the fixture with offset distance increasing. The results had a tendency to increase the stress on the neck portion of fixture with the offset and oblique loads increasing. The design of occlusal scheme should be allowed to distribute stress axially in maximum intercuspation and to decrease the angulation of cuspal incline.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.5
• /
• pp.754-763
• /
• 2018

The maritime ICT-convergence equipment are essentially required to a type approval (TA) certification that needs environmental and functional tests, to install in vessel. The environmental test is to experiment the possession for required durabilities of the target device in maritime environment, and the functional test is to check the required functions of target equipment based on international standard. In Korea, the environmental testing facilities amount to 227 sites, but there is no functional testing facility. Because of this, we establish a function test facility for the maritime ICT-equipment. In this paper, we analyze and design the functional testing requirement and required interlocking simulators for digital interfaces and navigation communication equipment. We propose the 2-steps of functional testing procedures, which are single test and integration test, to improve the reliability of testing result. The single test is to examine own functions of the target device, and the integration test is to check harmonized operation with other navigation and communication devices.

• Journal of the Korean Society of Radiology
• /
• v.8 no.2
• /
• pp.89-96
• /
• 2014

This paper tries to examine whether the application of joint mobilization to subjects who have the forward head posture due to malalignment in the cervical joint has influence on posture changes and functions in the cervical joint. The subjects were 39 students from G University in Gyeongsangbuk-do. The cervical joint mobilization was applied to 20 subjects and not to 19. The students with a cervical lordosis angle of $21^{\circ}C$ or less, an anterior weight bearing (AWB) of 15mm or greater, and a cervical extension ROM of $70^{\circ}C$ or less in terms of radiography were selected as subjects under their voluntary agreement. The patients actively performed the joint mobilization slowly 8 times per session while therapists continuously applied sustained accessory glide to their painful joints 3 times per week for 4 weeks along with the cervical expansion and flexion in SNAGS among other Mulligan's (1995) techniques. The measurement was carried out in terms of radiographic inspection and neck disability indexes. As a result of the experiment, it turned out that the subjects with the forward head posture had changes in the cervical AWB and ARA, the ranges of expansion and flexion, and the NDI(Neck Disability Index) after the intervention for the experimental group by applying cervical joint mobilization. There were no changes observed in the control group. In conclusion, the application of joint mobilization turned out to have influence on the improvement of cervical joint postures, and craniocervical region functions.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.9
• /
• pp.989-996
• /
• 2007

In this study, abiotic transformation of 1-naphthol(1-NP) via oxidative-coupling reaction and its reaction products were investigated in the presence of Mn oxides. The reaction products were characterized for their relative polarity using solvent extraction experiment and reverse-phase HPLC, and for structure using CCMS and LC/MS, and for absorption characteristics using UV-Vis spectrometry. The reaction products present in aqueous phase were more polar than parent naphthol and comprised of 1,4-naphthoquinon(1,4-NPQ) and oligomers such as dimers and trimers. Hydrophilic component present in water phase after solvent$(CH_2Cl_2)$ extractions was identified as naphthol polymerized products having molecular weight(m/z) ranging from 400 to 2,000, and showed similar UV-Vis. absorption characteristics to that of foil fulvic acid. Transformation of 1,4-NPQ, which is non-reactive to Mn oxide, to the polymerized products via cross-coupling reaction in the presence of 1-NP was also verified. In this experimental conditions(20.5 mg/L, 1-NP, 2.5 g/L $MnO_2$, pH 5), the transformation of 1-NP into the oligomers and polymerized products were about 83% of initial 1-NP concentrations, and more than 30% of the reaction products was estimated to be water insoluble fractions, not extracted by $H_2O$ methanol. Results from this study suggest that Mn oxide-mediated treatment of naphthol contaminated soils can achieve risk reduction through the formation of oligomers md polymer precipitation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.10
• /
• pp.1117-1125
• /
• 2007

In this paper, a study has been performed on the design of small loop probe and analysis of induced electromagnetic wave signal from a smartcard for contactless cryptographic analysis. Probes for cryptographic analysis are different from conventional EM probes, because the purpose of proposed probe is to obtain the information for secret key analysis of cryptographic system. The waveform of induced voltage on probe must be very close to radiated waveform from IC chip on smartcard because electromagnetic attack makes an attempt to analyze the radiated waveform from smartcard. In order to obtain secret key information, we need to study about cryptographic analysis using electromagnetic waves, an approximate model of source, characteristic of probe for cryptographic analysis, measurement of electromagnetic waves and calibration of probes. We measured power consumption signal on a smartcard chip and electromagnetic wave signal using proposed probe and compared with two signals of EMA point of view. We verified experimently the suitability of the proposed small loop probe for contactless cryptographic analysis by applying ARIA algorithm.

• Journal of The Korean Association For Science Education
• /
• v.21 no.2
• /
• pp.264-278
• /
• 2001

The purpose of this study was to develop the web based instruction(WBI) program, to examine its effects on the science achievement, the attitude toward science, and students' perceptions on the WBI learning. The WBI program on the content of oceanography unit in Earth Science for high schools was developed using Namo 4.0, JAVA-script, Flash 4, Video Capture of SnagIt, Animation Shop graphic tools. The treatment group consisted of students who participated in the WBI program developed in this study, and the control group consisted of students who participated in the module instruction using self-learning materials. The results from this study were as follows: First, the scores of science achievement of WBI group were significantly higher than those of module group. There was not interaction effect of treatment and students' learning ability. Second, there were no significant difference in the scores of the attitude towards science learning between WBI group and module group, and there was not interaction effect of treatment and students' learning ability. Third, in the perception questionnaire of WBI learning, many students showed the WBI learning were good in terms of causing interaction between learners and web based learning materials including various images and animations. However there are several students who showed learning difficulties. For example they wonder which part is more important and what order is proper to study in hypertext environment.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.3
• /
• pp.480-490
• /
• 2018

Recently, The MRV (monitoring, reporting and verification) regulation, which measures, reports and verifies the emission gas of vessel to head for member countries of Europe Union (EU), is being implemented. As part this reason, we develop a system that estimates simple fuel consumption and recommends optimized stop-over ports of vessel, to calculate amount of carbon emission. To do this, we analyze fuel, distance and time consumption between port and the other port based on stored voyage data for over 10 years of real-ship, and implement a simple fuel consumption estimation module using analyzed result. Also, we design and implement the optimized route recommendation algorithm, existing navigation route display function including comparison with the optimized routes and user custom route plan function. Therefore, we expect the developed system is helpful when makes a navigation route and so on by reference indexes and we anticipate the system to have a sense for future research which learns and predicts for accuracy result.

• Archives of Plastic Surgery
• /
• v.34 no.1
• /
• pp.93-98
• /
• 2007

Purpose: Many options are available for the incision and pocket selection in breast augmentation. Each method has its advantages and disadvantages. To leave an invisible operation scar and to achieve easier pocket dissection by the central location of the incision on the breast, we made a transareolar-perinipple incision. To overcome the disadvantages of the transareolar incision, originally advocated by Pitanguy in 1973, we modified the direction of incision line and dissection plane. Methods: To avoid the injury of 4th intercostal nerve responsible for nipple sensation, we made perinipple incision on the medial side of the nipple instead of trans-nipple incision and made the transareolar incision as 11-5 o'clock on the left side and 1-7 o'clock on the right side instead of 3-9 o'clock on both sides. To avoid the possible infection and breast feeding problem caused by the injury to the lactiferous duct, and the possible implant hernia caused by the incisions lying on a same plane of pocket dissection, we made a subcutaneous dissection just above the breast tissue medially down to the bottom of breast tissue and made a subglandular or subfascial pocket, which may avoid the injury of lactiferous duct and create different planes for skin incision and pocket dissection. Other advantages of the transareolar-perinipple incision include easier pocket dissection, less chance of hematoma, and as a result less postoperative pain because of the central location of the approach which allow finger dissection and meticulous bleeding control with direct vision, without any specialized instrument such as an endoscope or long mammary dissectors. As for pocket selection, we made dual pockets. We prefer subglandular or subfascial pocket. Also, we made a subpectoral pocket in the upper 1/4 of the pocket to add more volume on the upper part of the augmented breast, which can make aesthetically more desirable breasts in thin Asian women with small breasts. Possible disadvantages of our method are subclinical infection and scar widening, which could be overcome by meticulous operation techniques, antibiotic therapy, and intradermal tattooing. Results: From September, 2003 to August, 2005, 12 patients underwent breast augmentation using round smooth surface saline implants by our method. During the mean follow-up period of 13 months, there were no complications such as infection, hematoma, capsular contracture, and sensory change of nipple, and results were satisfactory. Conclusion: We suggest breast augmentation via transareolar-perinipple incision and dual pockets(subpectoral-subglandular or subfascial) as a valuable method in thin oriental women with small breasts.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1103-1106
• /
• 2011

Optimum application level of liquid pig manure for increasing Astragalus sinicus L. (ASASI) and Lolium multiflorum Lam. (LOLMU) yield was investigated. The green manure crop yield were generally high in the order of ALPM 100 ${\geqq}$ APLM 75 ${\geqq}$ APLM 50 ${\geqq}$ APLM 0 in site 1 (ASASI), and LPLM 100 ${\geqq}$ LPLM 75 > LPLM 50 ${\geqq}$ LPLM 0 in site 2 (LOLMU). The optimum application level of liquid pig manure was 100% of nitrogen fertilization level.

• Journal of Korean Society of Forest Science
• /
• v.105 no.4
• /
• pp.401-413
• /
• 2016

Forest resources utilization and variable disturbance history have been affected the rarity and conservation value of forest relict trees, which served as habitat for forest biodiversity, important carbon stock and cultural role include human and natural history in South Korea. This study was conducted to establish the baseline data for forest resources conservation by clarifying species diversity, spatial distribution and ecological characteristics (individual and habitat) of forest relict trees (DBH > 300 cm) based on the data getting from mountain trail, high resolution aerial photos and field professionals and field survey. As results, 54 taxa (18 family 32 genus 48 species 1 subspecies 3 variety and 2 form) as about 22% of tree species in Korea was identified in the field. 837 individuals of forest relict trees were observed and the majority of the trees was in Pinaceae, deciduous Fagaceae and Rosaceae, which families are abundant in population diversity. High elevation area was important to relict trees as mean altitudinal distribution was 1,200 m a.s.l as likely affected by human activity gradients and mid-steep slope and North aspect was important environment for the trees remain. Many individuals exhibited 'damage larger branch' (55.6%) and consequent relatively lower mean canopy coverages (below 80%). Synthetically, present diversity and abundance of relict forest trees in South Korea were the result of complex process among climate variation, local weather and biological factors and the trees of big and old were estimated to important forest biodiversity elements. In the future, clarifying the role and function of relict trees in forest ecosystem, in- and ex- situ programmes for important trees and habitat, and activities for building the background of conservation policy such as "Guideline for identifying and measurement of forest relict trees".