• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.31 no.3
• /
• pp.243-248
• /
• 2009

Purpose: Rehabilitation of the edentulous posterior maxilla with dental implants often poses difficulty because of insufficient bone volume caused by pneumatization of the maxillary sinus and by crestal bone resorption. Sinus grafting technique was developed to increase the vertical height to overcome this problem. The present study was designed to evaluate the sinus floor augmentation with anorganic bovine bone (Bio-$cera^{TM}$) using histomorphometric and clinical measures. Patients and methods: Thirteen patients were involved in this study and underwent total 14 sinus lift procedures. Residual bone height was ${\geq}2mm$ and ${\leq}6mm$. Lateral window approach was used, with grafting using Bio-$cera^{TM}$ only(n=1) or mixed with autogenous bone from ramus and/or maxillary tuberosity(n=13). After 6 months of healing, implant sites were created with 3mm diameter trephine and biopsies taken for histomorphometric analysis. The parameters assessed were area fraction of new bone, graft material and connective tissue. Immediate and 6 months after grafting surgery, and 6 months after implantation, computed tomography (CT) was taken and the sinus graft was evaluated morphometric analysis. After implant installation at the grafted area, the clinical outcome was checked. Results: Histomorphometry was done in ten patients.Bio-$cera^{TM}$ particles were surrounded by newly formed bone. The graft particles and newly formed bone were surrounded by connective tissue including small capillaries in some fields. Imaging processing revealed $24.86{\pm}7.59%$ of new bone, $38.20{\pm}13.19%$ connective tissue, and $36.92{\pm}14.51%$ of remaining Bio-$cera^{TM}$ particles. All grafted sites received an implant, and in all cases sufficient bone height was achieved to install implants. The increase in ridge height was about $15.9{\pm}1.8mm$ immediately after operation (from 13mm to 19mm). After 6 months operation, ridge height was reduced about $11.5{\pm}13.5%$. After implant installation, average marginal bone loss after 6 months was $0.3{\pm}0.15mm$. Conclusion: Bio-$cera^{TM}$ showed new bone formation similar with Bio-$Oss^{(R)}$ histomorphometrically and appeared to be an effective bone substitute in maxillary sinus augmentation procedure with the residual bone height from 2 to 6mm.

• Journal of Korean Academy of Nursing
• /
• v.25 no.4
• /
• pp.653-667
• /
• 1995

Post - operative wound infections have been a serious problem in nursing care in the operating room and appear to be strongly related to the infection occurring during the performance of operation. The purpose of this study is to identify patterns in duration of surgical hand scrub (SHS), to evaluate the method of SHS and to examine the rate of glove perforation. Subjects for this study include 244 doctors and 169 nurses working in the operative theatre of a hospital in Seoul area. Test samples and related data were collected from this medical facility between April 1, through 15, and July 1, through 5, 1995 by the author and a staff member working in the operating room. For the study, data on the SHS of doctors and nurses were obtained at the time of operation and multiple batches of surgical gloves worn by the operating doctors were collected after each operation. The duration of SHS was measured with a stop watch and the method of SHS was evaluated according to Scoring Hand Scrub Criteria (SHS Criteria) and expressed as SHS scores. For the analysis of the data, t-test was used to compare the differences in the duration and the SHS scores of doctors and nurses, and Pearson's correlation coefficient was used to examine the relationship between the SHS duration and the SHS scores. The results of the study are summarized as follows. 1) The mean time spent in each SHS was 167 seconds in nurses, and 127 seconds in doctors. The data comparing nurses and doctors indicated that there were significant differences in Our ation of SH S between these two groups (t=5.58, p=.000). 2) The mean time spent in the first SHS was 145 seconds and that in the End SHS, 135 seconds, and there was not a significant difference in the duration of the SHS between doctors and nurses (t=1.44, P=.156). 3) The mean time spent in the SHS by OS (Orthopaedic surgery) doctors was 162 seconds, 150 seconds by NS(Neurologic surgery), 121 seconds by GS(General surgery), 94 seconds by OPH(Opthalmology) and DS(Dental surgery), 82 seconds by URO(Urology), 78 seconds by PS(Plastic surgery) and 40 seconds by ENT(Ear, Nose & Throat) These also showed a significant difference in the duration of the SHS among the medical specialities (t=4.8, P=.0001). 4) The average SHS score of the nurses was 15.2, while that of doctors was 13.1. The statistical analysis showed that t-value was 3.66, p was. 000. This indicates that the nurses actually clean their hands more thoroughly than the doctors do. 5) The average SHS score of NS doctors was 15.5, 15.3 for doctors for OPH,14.3 for OS,12.7 for GS, 12.0 for DS, 11.7 for URO, 10.1 for PS, 7.5 for ENT. Comparison of the average SHS scores from 8 specialties showed that there was a significant differences in the patterns of the SHS (F=5.08, P=.000) among medical specialties. 6) It appears that the operating personnel scrub the palms and dorsum of their hand relatively well, however, less thorough the nails and fingers. 7) The more the operating personnel spend their time in hand scrubbing, the more correctly they clean their hands(r=.6427, P<.001). 8) The overall frequencies of perforation in all post-operative gloves tested was 38 out of 389 gloves (10.3%). The perforation rate for PS was 13%, 12.1% for GS,8.8% for 05, and 3.3% for NS.

• Korean Journal of Plant Resources
• /
• v.29 no.4
• /
• pp.479-494
• /
• 2016

The aim of this study is to select the superior resources of high yield, high content of functional material optimal to mechanical harvesting by the evaluation of crop growth and yield characteristics in sorghum germplasm. One hundred accessions of sorghum germplasm were used in this experiment. Days from seeding to heading date showed the range from 68 to 94 days with the highest frequency proportion was the group from 80 to 85 days, which occupied 34% (34 plant resources) of 100 germplasm. Ear types of 100 sorghum germplasm could be classified as 7 types of broom-tillering, half broom-tillering, extreme open-loose type, open-loose type, intermediate type, compact type, extreme-compact type of which intermediate type was the highest ratio of 28% (28 plant resources) of 100 germplasm. Yield showed the range from 106 to 365 ㎏/10a with the highest frequency proportion of it was the group from 150 to 200 ㎏/10a, which occupied 44% (44 plant resources) of 100 germplasm. Among 100 sorghum germplasm, 18 ideal resources of high yield and short plant height appropriate for mechanical harvesting were selected. In order to evaluate high content of functional substance, selected 18 resources were analyzed for total polyphenol content, DPPH radical scavenging activity and total anthocyanin content. Finally, we selected 5 resources of short plant height, high yield, high content of total polyphenol and high DPPH radical scavenging activity among 18 genetic resources.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.22 no.4
• /
• pp.172-186
• /
• 2017

Current study is a part of the efforts to assess the estuarine barrage effects on the coastal ecosystem induced by the Si flux changes. Surface sediments from Seomjin and Nakdong estuary and sediment cores from Nakdong estuary was analysed to investigate the effect of estuarine barrage on the distribution of grain size, organic matter (loss on ignition: LOI) and biogenic silica (BSi). The samples of Seomjin estuary were collected in March, 2015 and those of Nakdong estuary were collected in November, 2014. Generally, the longitudinal distribution of grain size, LOI and BSi in Seomjin estuary, natural estuary, was gradually changed. However mud (silt and clay), LOI and BSi increased from station mid-estuary where tide reaches year-round. The distribution of grain size, LOI and BSi in Nakdong estuary, however, were entirely different between inside and outside of estuarine barrage. The mud percentage and LOI were low and consistent in inside of the barrage except R05, inside of right gate, yet those of outside of the barrage were higher and varied by adjacent sluices. Mud, LOI and BSi of ND1 and ND2 decreased immediately after the construction of Nakdong estuarine barrage due to disturbance of sediment and decrease of sediment supply. To exclude the physical effects by the barrage, BSi excess ($BSi_{exc}$) was calculated using regression equation of BSi-LOI and BSi-mud of Seomjin estuary. $BSi_{exc}$ of Seomjin estuary decreased gradually from upper estuary to lower estuary. $BSi_{exc}$ of Nakdong estuary were positive in inside of the barrage and negative in outside of the barrage. BSi retention and shift of species composition of diatom by the barrage would affect $BSi_{exc}$ distribution. Before the construction of Nakdong estuarine barrage, $BSi_{exc}$ of ND2 was negative and consistent owing to high mud sedimentation. After the construction, $BSi_{exc}$ of ND2, however, fluctuated due to continuous disturbance of sediment due to construction of Eulsuk bridge and East gate.

• Journal of Animal Environmental Science
• /
• v.11 no.3
• /
• pp.207-214
• /
• 2005

To reduce phosphorus and nitrogen from the swine wastewater, magnesium chloride $(MgCl_2)$ was used as a reaction material for both soluble phosphorus (SP) and ammonia-nitrogen (AN). The initial value of SP content were $471mg/\ell$ far aeration test and $515 mg/\ell$ for NaOH addition test, but treatment of $MgCl_2$ reduced SP value to $5mg/\ell$ and $4mg/\ell$. The removal efficiency of $MgCl_2$ for SP showed $99\%$ in both treatment, and the removal efficiency of $MgCl_2$ for AN showed $15\%$ with treatment of aeration and $18\%$ with NaOH. All the experiments were done in a low temperature of 6 to $8^{\circ}C$, suggesting that this methods are possibly able to apply to a cold weather conditions. Moreover, the struvite crystal structure was identified by electronic microscope, implying that $MgCl_2$ is an effective material for removal of SP from swine wastewater In addition to the increased removal rate of the AN in wastewater, both $MgCl_2$ and $KH_2PO_4$ were added. The SP value was reduced by $99\%$ with 2g addition of the phosphate. The SP removal rate by 4g addition of the phosphate was increased only as $15-19\%$, but the quantity of removed SP was higher than that of 2g addition test. The value of AN was not reduced as expected by adding $KH_2PO_4$. The AN removal rate were low as $18\%$ and $15\%$ like as the level of the former test with $MgCl_2$ alone. Therefore, it is needed to examine closely the reaction mechanism f3r reducing both SP and AN simultaneously.

• Research in Community and Public Health Nursing
• /
• v.9 no.2
• /
• pp.467-481
• /
• 1998

The purpose of this survey, in which 2754 students from 35 middle schools from Taegu city participated, was to identify the degree and the relationship of sexual knowledge, sexual attitude and need for sex education. This information will provide useful data, and promote a more systematic, desirable and practical sex education. The data was collected from September 1 to November 8, 1997. Data was analyzed using the statistical computer package, SPSS to manipulate the data along with percentage, mean, $X^2$-test. t-test, F-test and Pearson correlation coefficient. The results from this study were summarized as follows: 1. The mean score of sex related knowledge showed significant differences between boys and girls in general knowledge(boys: 10.85 girls: 11.71, p=0.000), in the area of physical development(boys : 5.29 girls: 5.72, p=0.000), pregnancy & physiology (boys: 3.23 girls: 3.57, p=0.000) and venereal disease (boys: 2.33 girls: 2.42, p=0.000). 2. The mean score of sex related attitudes showed a significant differences between boys and girls on the whole(boys : 57.68 girls: 58.92, p=0.000), in the area of psychological differences of the other sex (boy: 26.13, girls: 28.08, p=0.000), and sexual delinquency and its prevention(boy: 14.28, girls: 13.68, p=0.000). However, in the area of other sex friendships (boy: 17.28, girls: 17.16, p=0.274). There were no significant differences between boys and girls. 3. Those who had a higher sex related knowledge score showed more positive attitudes towards sex, but was of no statistical significance(r= 0.312, p=0.000). 4. The majority of subjects wanted to learn about friendship with the other sex(40.1%), about physical and psychological differences in adolescence(24.0%), about prevention of sexual violence(15.0%), about pregnancy and delivery (7.5%), about venereal disease and medical cures(7.3%), about contraception methods (4.3%), as well as other aspects of sexual knowledge (1.8%), 5. The mean score of sex related knowledge generally was higher when one paid a lot of attention to health (F= 3. 148, p=0.014), when one's father was alive(t=3.930, p=0.000), and when one's mother was alive(t=2.807, p=0.005), Hobby activities also showed a significant difference(F=9.092, p=0.000). The mean score of sex related knowledge generally according higher when one had sex education(F=9.470, p=0.000), when one obtained sexual knowledges from a teacher (F = 5. 742, p=0.000), and when one had middle grade problems with sex(F=13.58 4, p=0.000). 6. The mean score of sex related attitudes generally showed significant differences when re ligion(F=2.691, p=0.03), hobbies (F= 3.499, p= 0.002) were considered. Those who had a father also had higher scores(t=2.538, p= 0.011). The mean score of sex related attitudes generally with respect to a subject's sex was higher when one had sex education(t=5.338, p= 0.000), when one had high grade problems with sex(F=6.023, p=0.002), and when one had the experience of friendship with the other sex(t= 8.106, p=0.000), The following suggestions are based on the above results, 1. Systematic sex education must be performed in middle schools in order to establish responsible attitudes toward sex, 2. Sexual knowledge, attitude, and general sex education classes must be performed seperately for early, middle, and late adolescents, In other words sex education programs are needed for each adolescent development stage.

• The Korean Journal of Financial Management
• /
• v.24 no.1
• /
• pp.29-58
• /
• 2007

We develop a model to estimate the value of growth opportunities, which is based on the seminal papers of M&M(1961, 1963) and Lee(2006). Making use of the estimation model, we estimate a new proxy variable of the growth opportunities, other than the usual proxy variables such as quasi Tobin's Q, MBR, and so on. The new proxy variable of growth opportunities can represent a necessary condition to identify whether the increase in new investments are successful or not. The empirical findings on the growth opportunities during the IMF currency crisis period and the post-IMF period are as follows; First, the overall success rate of new investments is as low as 50%, that means only half of the listed firms were increasing new investments when they had the growth opportunities. Second, during the crisis, one third of the listed firms were experiencing negative growth opportunities. However, during the post-IMF period, the growth opportunities on new investments were turned to be positive due to the turnaround efforts of listed firms. Third, the value of intangible assets, which are resulting from the investment of R&D and human capital, are becoming more important than ever. It seems to be true that larger portions of the value of growth opportunities are coming from the intangible assets, not from the increases in new investments of the physical assets.

• The Journal of Korean Academy of Prosthodontics
• /
• v.33 no.3
• /
• pp.467-491
• /
• 1995

In order to analyze the occlusin of intercuspation with maximun bite force, fifteen healthy adult subjects with the ages 23 to 27 were studied(Group1 ; 5-normal occlusion with Angle's Class1, Group2 ; 5-Angle's Class2 malocclusion, Group3 ; 5-Angle’s Class3 malocclusion). Head Position was fixed with occlusal plane paralleling to horizontal line and occlusal registration r cord was made with polyether rubber impression material(Ramitec, ESPECo. West Germany). After all subject were trained for maximum intercuspation at least 5 times, occlusal registration procedure was repeated for this study. Lower posterior rubber occlusal registration records were sliced with 1mm thickness using precision metal sliding channel(Hitachi Ind. Co., Japan). Gross sectional drawings were traced from occluding view of upper and lower posterior teeth on the rubber slices using digitizer, and superimposed for the determination of each drawing distance(Superimposed Rubber Pattern Method). Based on superimposed rubber pattern drawings, total area of occlusal view, sum of each area of the 5 divided occlusal contact provinces and its ratio, total area and number of occlusal contact area were determined to elucidate occlusal stability in the normal and abnormal occlusion groups. The data were analysed by t-test(p=0.05) to determine statistical significance. The obtained results were as follows : 1. Group1 showed the largest standard area with occlusal view of the lower posterior teeth and Group3 showed the smallest area. There was a significant difference between Group2 and Group3(p=0.025), and Gropu1 was not statistically different for both Group2 and Group3. 2. Means and ratio of the under 2.0mm area(D) and ratio showed $197.49mm^2$, 59.76% in Group1, $188,69mm^2$, 56.10% in Group2, and $174.23mm^2$, 55.76% in Group3. The results that Group1 has the most area/ratio and Group3 has the least area/ratio can be considered Group1 is the most advantageous for masticatory effective area, and Group3 is the least adnantageous. 3. Means and ratio of the under 1.0mm area(C) were $198.96mm^2$, 42.65% in Group1, 123.06$mm^2$, 46.58% in Group2, and $92.24mm^2$, 29.52% in Group3. These data means that Group1 is the most advantageous in terms of masticatory effective area and Group3 is the least. 4. Means and ratio of the under 0.5mm area(B) were $86.68mm^2$, 26.68% in Group1, $62.98mm^2$, 18.71% in Group2, and $36.44mm^2$, 11.66% in Group3. These can also be considered Group1 is the most advantageous for masticatory effective area and occlusal stability. 5. Means and ratio of the under 0.05mm area(A) were $30.92mm^2$, 9.21% in Group1, $14.31mm^2$, 4.25% in Group2, and $7.59mm^2$, 2.43% in Group3. The area ratio of the each subject group was(4.1) : (1.9) : (1)and the data of the under 0.05mm area has the intimate relationship with inter-group and intra-group data/ratio. 6. First molar showed the most occlusal contact points in all subject group and Group1 showed somewhat uniformly distributed occlusal contact point except first premolar. In Group2, all contact point in posterior teeth showed significantly reduced distribution except first molar. Group3 showed evenly distributed contace points in first and second molars.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.6
• /
• pp.670-680
• /
• 2010

A low power single-chip CMOS receiver for 60 GHz mobile application are proposed in this paper. The single-chip receiver consists of a 4-stage current re-use LNA with under 4 dB NF, Cgs compensating resistive mixer with -9.4 dB conversion gain, Ka-band low phase noise VCO with -113 dBc/Hz phase noise at 1 MHz offset from 26.89 GHz, high-suppression frequency doubler with -0.45 dB conversion gain, and 2-stage current re-use drive amplifier. The size of the fabricated receiver using a standard 0.13 ${\mu}m$ CMOS technology is 2.67 mm$\times$0.75 mm including probing pads. An RF bandwidth is 6.2 GHz, from 55 to 61.2 GHz and an LO tuning range is 7.14 GHz, from 48.45 GHz to 55.59 GHz. The If bandwidth is 5.25 GHz(4.75~10 GHz) The conversion gain and input P1 dB are -9.5 dB and -12.5 dBm, respectively, at RF frequency of 59 GHz. The proposed single-chip receiver describes very good noise performances and linearity with very low DC power consumption of only 21.9 mW.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.44 no.4 s.316
• /
• pp.60-69
• /
• 2007

The human eye usually experiences a loss of color sensitivity when it is subjected to high levels of luminance, and perceives a discrepancy in color between high and normal-luminance displays, generally known as a hue shift. Accordingly, this paper models the hue-shift phenomenon and proposes a hue-correction method to provide perceptual matching between high and normal-luminance displays. The value of hue-shift is determined by perceived hue matching experiments. At first the phenomenon is observed at three lightness levels, that is, the ratio of luminance is the same between high and normal-luminance display when the perceived hue matching experiments we performed. To quantify the hue-shift phenomenon for the whole hue angle, color patches with the same lightness are first created and equally spaced inside the hue angle. These patches are then displayed one-by-one on both displays with the ratio of luminance between two displays. Next, the hue value for each patch appearing on the high-luminance display is adjusted by observers until the perceived hue for the patches on both displays appears the same visually. After obtaining the hue-shift values, these values are fit piecewise to allow shifted-hue amounts to be approximately determined for arbitrary hue values of pixels in a high-luminance display and then used for correction. Essentially, input RGB values of an image is converted to CIELAB values, and then, LCh (lightness, chroma, and hue) values are calculated to obtain the hue values for all the pixels. These hue values are shifted according to the amount calculated by the functions of the hue-shift model. Finally, the corrected CIELAB values are calculated from corrected hue values, after that, output RGB values for all pixels are estimated. For evaluation, an observer's preference test was performed with hue-shift results and Almost observers conclude that the images from hue-shift model were visually matched with images on normal luminance display.