• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.2
• /
• pp.270-277
• /
• 2002

Since founded in 1959, it's well known that the KAPD has pioneered in the researches and clinical aspects of pediatric dentistry in Korea. It's official journal, the Journal of the KAPD, was first published in 1974 and has pressed total 956 articles up to now(March, 2001). In this study, all the articles pressed in this journal have been surveyed, focussing in their main theme, their chronological and thematic distribution. The thematic classification was made with the reference of the previous studies and renowned textbooks in pediatric dentistry. And we obtained the results as follows: 1. The researches on dental materials and dental equipments have shown continuous increase throughout the period. 2. The researches on dental caries, caries prevention and systemic disorders have occupied relatively high proportion consistently. 3. The researches on malocclusions and cysts/minor surgery have shown increasing tendency in the second period, but are decreasing in the third period. 4. The researches on craniofacial growth/development, tooth development/eruption, developmental disorders of teeth, management of eruption space have shown decreasing tendency. 5. The researches on behavioral research, oral habits, occlusion of primary-mixed dentition have shown very low proportion, reaching no more than 1% throughout the period.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.3
• /
• pp.368-373
• /
• 2010

The incisors function as instruments for biting and cutting food during mastication. They also support the lips and face and maintain vertical dimension. In addition, they contribute to overall normal arch appearance. They play important role during the articulation of speech and assist in guiding jaw closure. Extraction and space maintenance are the most common treatment for a tooth with poor prognosis. However, in the mixed dentition, extraction of the upper permanent incisors results in many complications, such as resorption of alveolar bone, poor esthetics, pronunciation, and mastication. Considering these various roles of incisors in oral cavity, approach for traumatized incisors, even the ones with poor prognosis, should be considered first prior to simple extraction. The dentist must take into account the age of the patient, growth potential, occlusion, oral hygiene status, economic status and motivation towards dental health in addition to patient compliance. In this case, although the prognosis was predicted to be unfavorable due to short root and mobility, we could save the central incisor using conservative treatment, reposition by orthodontic appliance instead of extraction.

• Journal of the Korean Chemical Society
• /
• v.52 no.1
• /
• pp.73-83
• /
• 2008

The purpose of this study was to investigate the types of conceptions of mixing phenomena related to dissolution and diffusion in high school students. The subjects of the investigation consisted of 108 students who took chemistry I course at 11th grade and 29 students who took chemistry II course at 12th grade. For this study, it was found that the many students had the alternative conception that chalk didn't dissolve in water because chalk was a nonpolar material. Most of the students understood the phenomena which carbon tetrachloride and water will not mix as the attraction conception. But many of the other students understood the phenomenon as characteristic of the materials such as difference of density. Many of the students understood the phenomenon of mixing ethanol and water constantly as ‘Attraction conception'. The phenomenon which is mixed ink and water was just accepted by the most students as the spreading of ink in water without understanding the reason of mixing. The phenomena of mixing iodine and carbon tetrachloride was understood as ‘Space conception' or ‘Attraction conception'. It could be inferred that the diverse alternative conceptions related to dissolution and diffusion phenomena were generated by the absence of entropy concept. Therefore, the explanations of science textbooks related to dissolution and diffusion phenomena need to change for students to understand them correctly.

• Journal of the Korean Chemical Society
• /
• v.37 no.1
• /
• pp.76-82
• /
• 1993

Two crystal structures of fully dehydrated Ca(II) and Tl(I) exchanged zeolite A, $Ca_{5.6}Tl_{0.8}-A (a = 12.242(2){\AA})\;and\;Ca_{1.4}Tl_{9.2}-A (a = 12.191(1){\AA})$, have been determined by single-crystal X-ray diffraction methods in the cubic space group Pm3m at 21(1)$^{\circ}C$. All crystals were ion exchanged in flowing streams of mixed $Ca(NO_3)_2\;and\;TINO_3$ aqueous solution with total concentration of 0.05M. All crystals were dehydrated at 360$^{\circ}C$ under $2{\times}10^{-6}\;torr$ for two days. The structures of the dehydrated $Ca_{5.6}Tl_{0.8}-A$ and $Ca_{1.4}Tl_{9.2}-A$ were refined to the final error indicies, $R_1$ = 0.072 and $R_2$ = 0.076 with 179 reflections for I > 3$\sigma$(I), and $R_1$ = 0.048 and $R_2$ = 0.043 with 226 reflections for I > 3$\sigma$(I), respectively. In each structure, Ca(II) ions are located on threefold axes associated with three 6-ring oxygens. $Ca^{2+}$ ions prefer to 6-ring sites and $Tl^+$ ions prefer to 8-ring sites when total number of exchanged cations per unit cell is more than 8.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.3
• /
• pp.371-375
• /
• 2002

The calcifying odontogenic cyst(COC) showed diverse terminology or classification, clinicopathologic features as well as in its biologic behavior, although it was recognized as a distinct clinicopathologic entity. The epithelial lining of a COC appears to have the ability to induce the formation of dental tissues in the adjacent connective tissue wall, and that other odontogenic tumors may sometimes be associated with it. This case is a COC associated with a complex odontoma involving an impacted left maxillary lateral incisor in a 5-year-old female child. Radiographic examination revealed a well-demarcated radiolucent lesion partially occupied by a radiopaque mass, involving the left lateral incisor crown. The histologic sections showed a cystic cavity lined with ameloblastic epithelium containing ghost cell masses with admixed with complex odontoma components. The presence of mixed radiolucent-radiopaque lesion in children as observed in this case, the possibility of COC must be considered. In this case, there was no recurrence 1 year after enucleation and the space control is ongoing now.

• Journal of the Korean Geographical Society
• /
• v.50 no.4
• /
• pp.375-391
• /
• 2015

Trees to arrest sand-shifting have been planted on most of coastal dunes in Korea and considered as conservative objects. However, we reconsider that the simplicity of these trees have hindered ecological roles of coastal dunes; geochemical cycle and habitats of endemic species in coastal ecosystem. We examined geochemical properties of sediments on Byunsuran dune field where is planted with pine trees. There are significant difference in properties between embryo dune sediments and foredune sediments, but there are not between foredune and secondary dune. There are no significant difference between pine forest sediments and mixed forest sediments. It is also not showed the difference between dune ridge sediments and swale sediments. Despite spatial diversity from appearance, geochemical properties are not linked with geomorphic and vegetational conditions because of dense planted trees on foredune. To recover natural properties of coastal dunes, we need to change the conservation scheme to increase geomorphic and ecological diversity.

• Journal of Digital Contents Society
• /
• v.19 no.2
• /
• pp.309-318
• /
• 2018

We proposed a marketing plan for the performing arts venue using realistic contents(VR, AR, and MR). The venue is a place where the audience can experience the performance directly. The marketing plan of the performance venue is as follows. Firstly, it is a marketing strategy that utilizes an arrangement of venue seats. It is possible to predict for watching a performance at angle and sight in performance venue seats that audience want through VR. This allows the theatre seats to be experienced in advance with the VR contents inducing the reservation of the seats with a high sense of immersion. Secondly, it is a marketing using PR and AD of performing arts through MR in the space with a large transient population. It is possible to promote dynamic promotion utilizing the sense of the presence of performing arts compared with existing static promotion means. Thirdly, it is a marketing strategy that utilizes actor characters in performance. The audience could be interested in the performing arts in advance via a preview of the AR contents of the pamphlet. Fourthly, it is a way to communicate with customers directly by establishing a VR social network to manage venue members. This will help attract an audience to revitalize the theatre venue.

• Journal of the Korean Chemical Society
• /
• v.37 no.6
• /
• pp.599-603
• /
• 1993

Crystal structure of bis(1,2-diaminopropane)palladium(II) bis(oxalato)palladate(II) has been determined by X-ray crystallography. Crystal data: $Pd_2C_{10}H_{10}N_{4}O_{8}$, $M_W$ = 573.09, orthorhombic, space group $P_{ccn}$ (No = 56), a = 16.178(5), b = 16.381(6), c = 6.685(2)$\{AA}$, V = 1771.6 $\{AA}^3$, $M_W$W = 573.09, $D_c$ = 2.014 g${\cdot}c\;m^{-3}$, Z = 4, T = 294K, F(000) = 1056.0 and $\mu$ = 20.466 c$m^{-1}$. The intensity data were collected with $Mo-K\alpha$ radiation (${\lambda}$ = 0.7107 $\AA)$ on an automatic four-circle diffractometer with a graphite monochromater. The structure was solved by Patterson method and refined by full matrix least-squares methods using Pivot weights. The final R and S values were R = 0.065, $R_W = 0.059, R_{all}$ = 0.065 and S = 4.315 for 605 observed reflections. Both cation and anion complexes are essentially planar and have dihedral angle of $18(l)^{\circ}$ between thier planes. In the crystal structure, they do not have the Magnus's salt type mixed stacks; instead, the complex anions form regular stacks along the c-axis with the M-M bond length of $3.343(5)\AA$ and their stacks are surrounded by the complex cations through hydrogen bonds with the nitrogen-oxygen distances of 2.94(3) and $3.31(4)\AA.$

• Polymer(Korea)
• /
• v.32 no.3
• /
• pp.251-255
• /
• 2008

This study suggested antistatic material which can increase anti-static properties and mechanical strength by mixing polystyrene for conveying electronic stuffs with metal salt and ester compound as a anti-static agent. We studied about mechanical, thermal and electrical characteristics by changing the contents of MAH of poly(styrene-co-maleic anhydride), compatibilizer. As the result of measuring residue space charge of the blends of HIPS(75)/TPU(25)/poly(styrene-co-maleic anhydride)(MAH weight ratio : 25, 32, 43.5 wt%), we could find small residue charge in the blend which MAH(25 wt%) was added and it showed the highest values in tensile strength. Additionally we found out the material to which compatibilizer was added kept better anti-static properties than one to which compatibilizer was not added. In the event we could confirm that the adding of PS-co-MAH enables two polymers were mixed well when HIPS/TPU was blended and anti-static agent made easier dissipative in the blend.

• Korean Journal of Bronchoesophagology
• /
• v.3 no.2
• /
• pp.293-301
• /
• 1997

The tonsillitis has long been one of the most common disease in the otolaryngologic field. Peritonsillar abscess occurs when bacterial infection of the tonsil spreads to the potential peritonsillar space deep behind the tonsil, and it usually occurs in patients with recurrent tonsillitis or in those with tonsillitis who have been inadequately treated. We studied retrospectively 71 patients who had been diagnosed as acute tonsillitis and 82 patients who had been diagnosed as peritonsillar abscess and had admitted in our department of the Ulsan Dong Kang Hospital from January, 1995 to September, 1997. Especially in the bacteriologic studies, we compared acute tonsillitis and peritonsillar abscess with chronic tonsillitis. The following results were obtained： 1) The sex distributions of acute tonsillitis were 47 males(66%) and 24 females(34%) cases, but 57 males(70%) and 25 females(30%) in cases of peritonsillar abscess. There were predominant in male and frequently affected in second and third decades in 53 cases(76%) of acute tonsillitis and 56 cases(68%) of peritonsillar abscess. 2) It was same found in each season. 3) The duration from onset of symptom to visit in our department was 3.92 days in cases of acute tonsillitis and 5.95 days in cases of peritonsillar abscess in average 4) The major symptoms were sore throat, swallowing difficult. And others were fever, fatigability, dysarthria, trismus, headache, otalgia. 5) Among the 71 cases of acute tonsillitis and 82 cases of peritonsillar abscess, most temperature of patients at visit were 36.6-37.5 $^{\circ}C$ in each 36 cases(51%), 57 cases(70%). 6) In each disease, 35 cases(47%), 45 cases(75%) consisted of single infection and 39 cases(53%), 15 cases(25%) consisted of mixed infection. In acute tonsillitis, 111 strains were isolated from 74 cases, the most common strain was 69 strains(62.2%) of $\alpha$-hemolytic streptococci. In the peritonsillar abscess, 77 strains were isolated from 60 cases, the most common strain was 49 strains(63.6%) of $\alpha$-hemolytic streptococci. In chronic tonsillitis, 563 strains were isolated from 382 cases, the most common strain was 334 strains(50.3%) of $\alpha$-hemolytic streptococci. 7) In acute tonsillitis and peritonsillar abscess, the most common leukocyte levels were reported with 10, 000-15, 000/$\mu$L in 23 cases(32%). The CRP levels were reported with abnormal findings in 61 cases(97%), 63 cases(95%) above 0.3 in each cases.