• Journal of Marine Bioscience and Biotechnology
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• v.7 no.2
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• pp.58-70
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• 2015

Injectable RGD-bioconjugated Mussel Adhesive Proteins (RGD-MAPs) composite hydroxypropyl methylcellulose (HPMC) hydrogels provide local periodontal tissue for bone filling in periodontal surgery. Previously we developed a novel type of injectable self-supported hydrogel (2 mg/ml of RGD-MAPs/HPMC) based porcine nano hydroxyapatite (MPH) for dental graft, which could good handling property, biodegradation or biocompatibility with the hydrogel disassembly and provided efficient cell adhesion activity and no inflammatory responses. Herein, the aim of this work was to evaluate bone formation following implantation of MPH and collagen membrane in rabbit calvarial defects. Eight male New Zealand rabbits were used and four circular calvarial defects were created on each animal. Defects were filled with different graft materials: 1) collagen membrane, 2) collagen membrane with MPH, 3) collagen membrane with bovine bone hydroxyapatite (BBH), and 4) control. The animals were sacrificed after 2 and 8 weeks of healing periods for histologic analysis. Both sites receiving MPH and BBH showed statistically increased augmented volume and new bone formation (p < 0.05). However, there was no statistical difference in new bone formation between the MPH, BBH and collagen membrane group at all healing periods. Within the limits of this study, collagen membrane with MPH was an effective material for bone formation and space maintaining in rabbit calvarial defects.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.744-753
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• 2015

This paper presents the results of research on developing marine unified communications to provide VoIP service based on marine satellites. With the recent popularity of smart-phones and other mobile devices, the demand for Internet-based wired and wireless unified technology has been growing in marine environments, and increasing interest is being directed to VoIP products and service models with high price competitiveness and the ability to deliver a variety of services. In this regard, this research designed three instruments, developed their unit modules, and verified their performances. These three instruments included the following: (1) a marine VoIP module equipped with an analogue gateway that can be linked to the existing devices used in vessels, which is more than 80% smaller than that of a land system; (2) a text/voice/video engine for marine satellite communications that runs on technology that minimizes communication data usage, which is a core technology for a marine VoIP service; and (3) a unified communication service that can support multilateral cloud-based message conversations, telephone number-based call functions, and voice/video calling between a private space in a ship and shore.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.105-127
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• 1999

Application of the soil nailing method is continuously extended in maintaining stable excavations and slopes. Occasionally, however, ground anchor support system may not be used because of space limitations in urban excavation sites nearby the existing structures. In this case, soil nailing system with relatively short length of nails could be efficiently adopted as an alternative method. The general soil nailing support system, however, may result in excessive deformations particularly in an excavation zone of the existing weak subsoils. Pretensioning the soil nails then, could play important roles in reducing deformations mainly in an upper part of the nailed-soil excavation system as well as improving local stability. In the present study, the analytical procedure and design technique are proposed to evaluate maximum pretension force and stability of the pretensioned soil nailing system. Also proposed are techniques to determine the required thickness of a shotcrete facing and to estimate probability of a failure against the punching shear. The predicted results are compared with the limited measurements obtained from the excavation site constructed by using the pretensioned soil nails. Based on the proposed procedure and technique, effects of the radius of a influence circle and dilatancy angle on the thickness of a shotcrete facing, bonded length and safety factors are analyzed. In addition, effects of the reduction of deformations expected by pretensioning of the soil nails are examined in detail throughout an illustrative example and FLAC$^{2D}$ program analysis.s.

• Korean Journal of Optics and Photonics
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• v.25 no.4
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• pp.216-220
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• 2014

We have synthesized a $CaMgSi_2O_6:Eu^{2+}$ blue phosphor via a solid-state reaction method. The $CaMgSi_2O_6:Eu^{2+}$ phosphor has monoclinic structure with a space group of C2/c (15), and an emission band peaking at 450 nm (blue) due to the $4f^7-4f^65d$ transition of the $Eu^{2+}ion$. The emission intensity at $100^{\circ}C$ is 54% of the value at room temperature. A white LED was fabricated by integrating a UV LED (400 nm) with our blue phosphor plus two commercial green and red phosphors. The white LED shows a color temperature of 3500 K with a color rendering index of 87 (x = 0.3936, y = 0.3605), and a luminous efficiency of 18 lm/W. The white LED shows a luminance maintenance of 97% after operation at 350 mA for 400 hours at $85^{\circ}C$.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.113-122
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• 2021

This study begins on the basis of Jacques Lacan's article 『Logical Time and Assertions of Preemptive Certainty: A New Sophism』 published in the reissue of 『Art Note Les Cahiers d'Art』 in March 1945. In this paper, a guard presents an esoteric problem to three prisoners. If the problem is solved, the prisoner is released. A condition is given to solve a problem. Conversation between prisoners is prohibited, and the disc behind them cannot be seen. In this time and space, prisoners place themselves in logical time through the 'time of understanding' in order to become the chosen ones. We always live in logical time. We will argue the point at which Lacan destroys logical time in psychoanalysis. Time in Lacanian psychoanalysis transcends time divisions of the past, present, and future. Our time is always the past in the present. In Lacanian psychoanalysis, logical time is the time in the Other. The transcendence of the Lacanian psychoanalysis concept of time shows the deviation of logical time. In this text, We try to prove how Lacan contrasts psychoanalysis and the problem of time with time in the other. First, we will examine how logical time and impulse are related in psychoanalysis. Second, the postmortemity of the signifient (signifier) will be discussed. Third, Lacan psychoanalysis will present the transcendence of time. In conclusion, We will present the view that the time of Lacan psychoanalysis is flowing backwards. In Lacanian psychoanalysis, we try to prove that logical time is in the territory of the Other and is infinite time.

• Journal of the Korean Society of Food Culture
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• v.22 no.2
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• pp.246-253
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• 2007

Mineral and volatile flavor compounds of Pimpinella brochycarpa N., a perennial Korean medicinal plant of the Umbelliferae family, were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and simultaneous steam distillation extract (SDE)-gas chromatography mass spectrometry (GC/MS), head space solid phase micro-extraction (HS-SPME)-GC/MS. Mineral contents of the stalks and leaves were compared and the flavor patterns of the fresh and the shady air-dried samples were obtained by the electronic nose (EN) with 6 metal oxide sensors. Principal component analysis (PCA) was carried out using the data obtained from EN. The 1st principal values of the fresh samples have + values and the shady air-dried have - values. The essential oil extracted from the fresh and the shady air-dried by SDE method contain 58 and 31 flavor compounds. When HS-SPME method with CAR/PDMS fiber and PDMS fiber were used, 34 and 21 flavor compounds. The principal volatile components of Pimpinella brachycarpa N. were ${\alpha}$-selinene, germacrene D, and myrcene.

• Journal of the Korean Chemical Society
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• v.40 no.7
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• pp.474-482
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• 1996

Two crystal structures of the vacuum dehydrated $Ag^+$-exchanged zeolite X have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21(1)$^{\circ}C$ (a=24.922(1)${\AA}$ and a=24.901(1)${\AA}$, respectively). Each crystal was ion exchanged in flowing streams of aqueous $AgNO_3$ for three days. The first crystal was dehydrated at 300$^{\circ}C$ and $2{\times}10^{-6$torr for two days. The second crystal was similarly dehydrated at 350$^{\circ}C$. Their structures were refined to the final error indices, $R_1=0.095\;and\;R_2=0.092$ with 227 reflections, and $R_1=0.096\;and\;R_2=0.087$ with 334 reflections, respectively, for which I > 3${\sigma}$(I). In the first crystal, Ag species are found at five different crystallographic sites: sixteen $Ag^+$ ions fill the site I, the center of the double 6-ring, thirty-two Ag0 atoms fill the I' site in the sodalite cavities opposite double six-rings, seventeen $Ag^+$ ions lie at the 32-fold site II' inside the sodalite cavity at the single six-oxygen ring in the supercage, fifteen Ag+ ions lie at the 32-fold site II, in the supercage, and the remaining twelve $Ag^+$ ions lie at site III' in the supercage at a little off two-fold axes. In the second crystal, all Ag species are located similarly as crystal 1; 16 at site I, 28 at site I', 16 at site II, 16 at site II', 6 at site III and 6 at site III'. Total 88 silver species were found per unit cell. The remaining four Ag atoms were migrated out of the zeolite framework to form small silver crystallites on the surface of the zeolite single crystal. In the first structure, the numbers of Ag atoms per unit cell are approximately 32.0 and these may form tetrahedral $Ag_4$ clusters at the centers of the sodalite cavities. The probable four-atom cluster is stabilized by coordination to two $Ag^+$ ions. The Ag-Ag distance in the cluster, ca. 3.05 ${\AA}$, is a little longer than 2.89 ${\AA}$, Ag-Ag distance in silver metal. At least two six-ring $Ag^+$ ions on sodalite cavity (site II') must necessarily approach this cluster and this cluster may be viewed as a distorted octahedral silver cluster, (Ag6)2+.

• Korean Journal of Health Education and Promotion
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• v.16 no.1
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• pp.31-43
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• 1999

Increase of automobiles become today's environmental problem decreasing space for our children's playground. The traffic situation around us shows automobiles over filled the public roads and started to intrude even on the side walks. Children's traffic safety education for the awareness of the danger from traffic mishaps, and for the behavior to cope with preventives measure by continual learning programs in systematized method is very important need in current health education. For this research, the subject was represented by 243 students from 4th grade in D Elementary School located at Daechi-dong, Seoul. During total of 5 weeks (September 4, 1997 to September 30, 1997), lessons were taught to the subject. Lessons consist of traffic safety education and customized education program that were designed and developed specificially for the subject level. In this research, Case group of 3 classes and control group of 3classes were predetermined before subject's degree of knowledge, attitude, and practice was analized. The difference before and after the training of this education was observed to verify the effectively and to find the influential factors of this education program. On September 2-3, survey study was performed after the training. the results of this study were as follows: 1. The knowledge analysis from the comparison between before and after of the training shows case group and control group scored(8.36, 8.86) before the traning, but scored(10.36, 8.52) after the traning. the difference from the result of the case group is statistically significant(p〈0.001). 2. The attitude analysis from the comparison between before and after of the training shows case group and control group scored(48.23, 49.87) before the training, but scored (51.05, 48.45) after the traning. the difference from the result of the case group is statistically significant(p〈0.001) 3. The practice analysis from the comparison between before and after of the training shows case group and control group scored (27.42, 28.08) before the training, but scored(30.49, 28.25) after the training. The differece from the result of the case group is statistically significant (p〈0.001). 4. The correlation analysis of traffic safety education's influence on traffic safety knowledge, attitude, and practice before training shows the relationship between attitude and practice was satistically significant(p〈0.05). The result after the training shows the relationship between knowledge and attitude, attitude and practice, and knowledge and practice was all statistically significant(p〈0.001).

• Tunnel and Underground Space
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• v.22 no.1
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• pp.69-76
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• 2012

Theoretical backgrounds on the experimental methods of explosive welding, explosive forming and shock consolidation of powders are introduced. Explosive welding experiments of titanium (Ti) and stainless steel (SUS 304) plate were carried out. It was revealed that a series of waves of metal jet are generated in the contact surface between both materials; and that the optimal collision velocity and collision angle is about 2,100~2,800 m/s and $15{\sim}20^{\circ}$, respectively. Also, explosive forming experiments of Al plate were performed and compared to a conventional press forming method. The results confirmed that the shock-loaded Al plate has a larger curvature deformation than those made using conventional press forming. For shock consolidation of powders, the propagation behaviors of a detonation wave and underwater shock wave generated by explosion of an explosive are investigated by means of numerical calculation. The results revealed that the generation and convergence of reflected waves occur at the wall and center position of water column, and also the peak pressure of the converged reflected waves was 20 GPa which exceeds the detonation pressure. As results from the consolidation experiments of metal/ceramic powders ($Fe_{11.2}La_2O_3Co_{0.7}Si_{1.1}$), shock-consolidated $Fe_{11.2}La_2O_3Co_{0.7}Si_{1.1}$ bulk without cracks was successfully obtained by adapting the suggested water container and strong bonding between powder particles was confirmed through microscopic observations.

• Journal of the Korean Dietetic Association
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• v.10 no.4
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• pp.467-475
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• 2004

The purposes of this exploratory study were to a) verify the first image remember percentage about foodservice and the desire to eat, b) identify detail attributes on the 'food taste' and 'menu variety', the most important problem of the foodservice, c) decide the ranking for improvement of the identified detail attributes, and d) applicate from customer feedback to foodservice operation in the B&I(business & industry) foodservice. For the more reliable result, customer opinion was collected by qualitative research methodology, such as open-ended questionnaire and in-depth interview. The result was followed as : the firstly, the operation circumstance was total 6,700 meal number a day through in-depth interview and 3 types of meal was served. The secondly, the average usage a week was the 7.4 times(B foodservice(B1F)) and the 1.8 times(A foodservice(3F)), respectively. Using reasons of foodservice were 'broad extent', 'menu type', 'shifting convenience' and etc on B foodservice(B1F) and 'menu type', 'clean space' and etc on A foodservice(3F), but the disadvantages of both foodservice were 'complication on peak time', 'the decline of food taste', and 'the absence of menu variety'. 'The decline of food taste' and 'the absence of menu variety' were pointed out the problem asked immediate improvement. The thirdly, it was examined that the first remember about foodservice were 'menu type' and 'foodservice environment' on A foodservice(3F) and 'foodservice environment(atmosphere)' on B foodservice(B1F). The last result, the detail attributes about food taste were ranked respectively 'a salt taste', 'balance of 5 taste at a meal', 'taste of food characteristic' and the unsatisfaction attributes about menu variety were ranked respectively 'serving frequently a same menu', 'the absence of various taste', 'using frequently a same cooking preparation'.