• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.202-205
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• 2010

Introduction: The aim of the present study was to investigate the effect of mechanical irrigation in combination with mouthwash of antimicrobial agents on salivary bacterial counts. Materials and Methods: This study was performed with a randomized study employing a panel of 40 healthy volunteers (20 males and 20 females) between the age of 26 and 32 years. Volunteers were randomly put in one of four treatment groups. In the first group, 0.2 mL of non-stimulatory saliva was collected from every subjective person. Then, saliva was collected after rinsing with chlorhexidine (CHX) for 1 minute. In the second group, non-stimulatory saliva was collected, and then saliva was collected after rinsing with CHX and irrigation with saline. In the third and fourth groups, the same procedures as the first and second groups were performed with povidone iodine (PVI) instead of CHX. All of these samples were cultured for 48 hours aerobically. The reduction rates of colony-forming units (CFU) were calculated for each group. The reduction rate between each group was tested statistically using student t-test. Results: Using CHX in combination with saline irrigation showed a significant decrease of the salivary bacterial CFU when compared with only using CHX.(P<0.01) And using PVI with saline irrigation showed a little decrease of the CFU when compared with only using PVI, but there was no statistical significance.(P>0.01) Conclusion: It was concluded that the CHX or PVI used with saline irrigation made the salivary bacterial counts reduced more than when CHX or PVI was used alone as an oral antiseptic agent.

• Journal of the Korean Dietetic Association
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• v.5 no.2
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• pp.194-204
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• 1999

The objectives of this study were to assess the current practices of implementing selective menus and to identify the perception of foodservice manager and customer on selective menus for hospital foodservice would be fulfilled. Two types of questionnaires for hospital foodservice managers as well as customers were developed. Questionnaires were distributed to managers of 8 hospital foodservice department and 317 customers of patient meal service, and 6 managers and 139 customers were responded. The data were analyzed using frequency and t-test. The results of this study can be summarized as follows : 1. In hospital foodservice operations, the selective menu pattern was first introduced by L hospital on June 1994 in Seoul and recently 8 hospitals were currently implementing selective menus. But using rate of selective menus by patients were relatively low(23.2%), ranging from 15% to 32%. 2. Customers' needs for selective menus were rated significantly higher in the group of patients(4.24/5) who chose the selective menus than their counterpart(3.88/5). 3. The main reason not choosing selective menus was identified by patients as 'not knowing the implementation of selective menus'(52.6%), inconvenient factors in using selective menus for customer were also identified as orders : 'lack of nutrition information on menu item'(38.6%), 'complexity in procedure'(29.8%), and 'lack of menu variety'(26.3%). However managers considered 'managerial burden' and 'limited human resource' as main obstacle to implement the selective menu pattern. 4. Customers indicated 'variety of menu', 'active public relations' as effective methods to enhance using rate of selective menus, however, foodservice manager indicated 'variety of menu'(50%), 'improvement of quality'(16.7%), and 'simplicity in procedure'(16.7%). Based on the results of this study, following recommendations have been suggested : Managers in patient meal service should recognize customer needs for implementing selective menus and pay more attention in implementing selective menus and activating this program. For more effective implementation of activating selective menu program, the foodservice department should establish action plan on 'active publicity work', 'simplicity in procedures', 'variety of menu' and 'improvement of quality'. Especially nutrition informations on meals should be provided for customers in order to elevate participation rate.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.1-11
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• 1999

The Korean government is developing a systematic plan of integrated coastal management for effective conservation, utilization, and development of coastal areas. For this plan, integrated maps of land maps and nautical charts are indispensable. However, these maps are not made, nor studied yet in terms of integration, although digital maps(DM) on land and electronic nautical charts(ENC) have been recently developed by Korean Geography Institute and National Marine Investigation Institute, respectively. In this study, as preliminary studies to make eventual integrated maps, the concept of coastal areas are defined, specifically, coastal lines from DM and ENC are matched against each other. Issues on map production procedures, coordinate systems, and map projections, are carefully considered. A test coastal area located in Seo-Gu, Pusan, over 14 km of coastal lines is selected for the edge matching of coastal lines. RMS differences are 13.83 m and 4.37 m over man-made coastal lines and natural coast lines, respectively, which are quite larger considering a scale difference and other factors. However, no systematic differences are found.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.145-157
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• 2000

Cytotoxic substances in dental calculus and root cementum of periodontally diseased teeth inhibit new attachment and regeneration. The purpose of scaling and root planing is to remove pathologic structures harboring these cytotoxic substances in order to create a biologically acceptable root surface. However, these procedures inevitably leave a non-biocompatible smear layer. Conventionally, the smear layer has been removed with low pH etching agents such as citric acid, phosphoric acid and tetracycline hydrochloride(TC). Lately, a supersaturated neutral pH etching solution of ethylene diamine tetraacetic acid(EDTA) has been found to be as effective as low pH etchants with respect to smear removal and to be superior in exposing root surfaceassociated collagen. The aim of the present study was to determine the effect of root surface treatment using EDTA on the initial attachment of human gingival fibroblasts. 27 human teeth, extracted due to severe periodontitis, were cut into dentin slices after root planing. The specimens were divided into TC group(treated with $50㎎/m{\ell}$ tetracycline-HCl, pH 1.52), EDTA group(treated with 17% EDTA, pH 7.4), and non-treated control group. After sterilization, 5th subcultured human gingival fibroblasts were seeded in each culture well containing a prepared root slice and incubated for 15 min., 60 min., and 4 hours in 5% $CO_2$ incubator at $37^{\circ}C$. At each incubation time, the number of attached fibroblasts were counted on the microphotographs taken at a magnification of x100. The difference of the number of attached cells between groups was statistically analyzed by the ANOVA followed by Duncan test in SPSS/PC＋programs. The results were as follows : 1. After incubation for 15 min, the attached cells were significantly more in EDTA group and TC group than non-treated control group(p<0.05), but there was no significance in the difference between EDTA group and TC group(p>0.1). 2. After incubation for 60 min and 4 hours, there was no significant difference in the number of attached cells between all groups(p>0.1). 3. In both EDTA group and TC group, there was no significant difference in the number of attached cells between different incubation(p>0.1). But in control group, the number of attached cells was significantly increased after incubation for 60 min, compared with incubation for 15 min(p<0.05). The above results suggest that root surface treatment using EDTA could enhance the initial attachment of gingival fibroblasts to root surface as effective as tetracycline-HCl.

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.181-192
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• 2007

Periodontal surgery as part of the treatment of periodontal disease is mainly performed 1) to gain access to diseased areas for adequate cleaning; 2) to achieve pocket reduction or elimination; and 3) to restore the periodontal tissues lost through the disease; i.e., a new attachment formation of periodontal regeneration. To accomplish the latter, often referred to as the ultimate goal of periodontal therapy, a number of surgical procedures have been advocated throughout the years. Clinical studies have demonstrated that considerable gain of clinical attachment and bone can be achieved following guided tissue regeneration (GTR) therapy of intrabony defects. The aim of this study was to analyse the radiographic bone changes 2-year after GTR using a bone graft material and nonresorbable membrane. Patients attending the department of periodontics of Kyungpook National University Hospital were studied. Patients had clinical and radiographic evidence of intrabony defect(s), 33 sites of 30 patients aged 32 to 56 (mean age 45.6) were treated by GTR with a bone graft material and nonresorbable membrane. Baseline and 2-year follow-up radiographs were collected and evaluated for this study. Radiographic assessment includes a bone fill, bone crest change, defect resolution, and % of defect resolution. Pre- and post-treatment differences between variables (maxilla and mandible, defect depth, defect angle, bone graft materials) using the paired t-test were examined. We observed $2.86{\pm}1,87mm$ of bone fill, $065{\pm}0.79mm$ of crestal resorption, $3.49{\pm}2.11mm$ of defect resolution, and $44.42{\pm}19.51%$ of percentage of defect resolution. Mandible, deeper initial defect depth, narrower initial defect angle showed greater bone fill, defect resolution, and % of defect resolution. But no difference was observed between xenograft and allograft. Outcome of GTR as a therapy of intrabony defect was better than other therapy, but herein, good oral hygiene maintenance as a anti-infective treatment and periodic recall check of patients are essential.

• Journal of Periodontal and Implant Science
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• v.50 no.1
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• pp.56-66
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• 2020

Purpose: A stability-measuring device that utilizes damping capacity analysis (DCA) has recently been introduced in the field of dental implantology. This study aimed to evaluate the sensitivity and reliability of this device by measuring the implant stability of ex vivo samples in comparison with a resonance frequency analysis (RFA) device. Methods: Six implant beds were prepared in porcine ribs using 3 different drilling protocols to simulate various implant stability conditions. Thirty-six pork ribs and 216 bone-level implants measuring 10 mm in height were used. The implant beds were prepared using 1 of the following 3 drilling protocols: 10-mm drilling depth with a 3.5-mm-diameter twist drill, 5-mm drilling depth with a 4.0-mm-diameter twist drill, and 10-mm drilling depth with a 4.0-mm-diameter twist drill. The first 108 implants were external-connection implants 4.0 mm in diameter, while the other 108 implants were internal-connection implants 4.3 mm in diameter. The peak insertion torque (PIT) during implant placement, the stability values obtained with DCA and RFA devices after implant placement, and the peak removal torque (PRT) during implant removal were measured. Results: The intraclass correlation coefficients (ICCs) of the implant stability quotient (ISQ) results obtained using the RFA device at the medial, distal, ventral, and dorsal points were 0.997, 0.994, 0.994, and 0.998, respectively. The ICCs of the implant stability test (IST) results obtained using the DCA device at the corresponding locations were 0.972, 0.975, 0.974, and 0.976, respectively. Logarithmic relationships between PIT and IST, PIT and ISQ, PRT and IST, and PRT and ISQ were observed. The mean absolute difference between the ISQ and IST values on a Bland-Altman plot was -6.76 (-25.05 to 11.53, P<0.05). Conclusions: Within the limits of ex vivo studies, measurements made using the RFA and DCA devices were found to be correlated under a variety of stability conditions.

• Fire Science and Engineering
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• v.34 no.3
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• pp.141-149
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• 2020

The Korea Industrial Standards (KS) stipulates methods and test procedures for measuring the horizontal combustibility of cellular plastics exposed to small flames (KS M ISO 9772:2018) and recommendations regarding the magnetic digestion of extruded polystyrene insulation (XPS) for measurement results (KS M 3808:2020). Although products that are certified to conform to KS standards must have burning characteristics (self-extinguishing), they are incinerated and spread by welds at construction sites, causing significant human and property damages. In this study, XPS produced by five companies, certified by KS, and sold in the market were purchased and tested for ignition and diffusion caused by a weld bullion at a construction site. The results showed that the five products had differences in performance. Three out of the five products were found to be self-saturated, but the other two were easily ignited and diffused, making it difficult for them to be self-extinguishing. Based on the result of this experimental investigation in line with the KS regulations, all the three types of products, including two types of products that were incinerated through weld defects, were found to be non-self-extinguishing, as specified in KS M 3808.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.90-94
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• 2007

Location tracking automation of resources in construction industry is one of the most important procedures to improve construction project performance and reduce the period of construction. Recently, location tracking technologies have proven to be effective in tracking construction materials and equipment in real time through the instrumentality of RFID (Radio Frequency Identification). By using wireless communication and inter-working system between RFID and USN, it is possible that construction engineers receive the location information of construction resources without additional efforts that move the RFID reader to read tags periodically. In the inter-working system, RFID reader delivers the acquired materials information to sensor node which is connected by serial interface. Then sensor node transmits the received data to the data aggregation terminal that is a sink node. The data aggregation terminal can transmit collected data to construction manager who is out of construction site using infrastructure such as CDMA(Code Division Multiple Access) network. The combination model of the two system and field test scenarios are presented in this paper.

• Journal of Biomedical Engineering Research
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• v.35 no.5
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• pp.160-168
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• 2014

Continuous body temperature monitoring is useful and essential in diverse medical procedures such as infection onset detection, therapeutic hypothermia, circadian rhythm monitoring, sleep disorder assessment, and gynecological research. However, the existing thermometers are too invasive or intrusive to be applied to long-term body temperature monitoring. In our previous study, we invented the bi-medium deep body thermometer which can noninvasively and continuously monitor deep tissue temperature. And the ratio of thermal resistances expressed as K-value should be obtained to estimate body temperature with the thermometer and it can be different under various measurement environments. Although the device was proven to be useful through preliminary simulation test and small group of human study, the experimental environment was restrictive in our previous approach. In this study, a finite element simulation was executed to obtain the K-value and evaluate the accuracy of bi-medium thermometer under various measurement environments. In addition, K-value estimation equation was developed by analyzing the influence of 5 measurement environmental factors (medium length, medium height, tissue depth, blood perfusion rate, and ambient temperature) on K-value. The results revealed that the estimation accuracy of bi-medium deep body thermometer based on computer simulation was very high (RMSE < $0.003^{\circ}C$) in various measurement environments. Also, bi-medium deep body thermometer based on K-value estimation equation showed relatively accurate results (RMSE < $0.3^{\circ}C$) except for one case. Although the K-value estimation technology should be improved for more accurate body temperature estimation, the results of finite element simulation showed that bi-medium deep body thermometer could accurately measure various tissue temperatures under diverse environments.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.471-480
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• 2006

Recently, multimedia communication services, such as video conferencing and voice over IP, have been rapidly spread. H.323 is an international standard that specifies the components, protocols and procedures that provide multimedia communication services of real-time audio, video, and data communications over packet networks, including IP based networks. H.323 is applied to many commercial services because it supports various network environments and has a good performance. But communication services based on H.323 may have some problem because of current network trouble or mis-implementation of H.323. The understanding of this problem is a critical issue because it improves the quality of service and is easy to service maintenance. In this paper, we implement the analysis system for H.323 protocol wihch includes H.245, H.225.0, RTP, RTCP, and so on. Tills system is able to capture, parse, and present the H.323 protocol in real-time. Through the operation test and performance evaluation, we prove that our system is a useful to analyze and understand the problems for communication services based on H.323.