• Korean Chemical Engineering Research
• /
• v.50 no.6
• /
• pp.980-987
• /
• 2012

Nonpoint source pollution causes leaks and overtopping, depending on the state of the sewer network as well as aggravates the pollution load of the aqueous water system as it is introduced into the sewer by wash-off. According, the need for efficient sewer monitoring system which can manage the sewage flowrate, water quality, inflow/infiltration and overflow has increased for sewer maintenance and the prevention of environmental pollution. However, the sewer monitoring is not easy since the sewer network is built in underground with the complex nature of its structure and connections. Sewer decontamination mechanism as well as pipe network monitoring and fault diagnosis of water network system on system analysis proposed in this study. First, the pollution removal pattern and behavior of contaminants in the sewer pipe network is analyzed by using sewer process simulation program, stormwater & wastewater management model for expert (XP-SWMM). Second, the sewer network fault diagnosis was performed using the multivariate statistical monitoring to monitor water quality in the sewer and detect the sewer leakage and burst. Sewer decontamination mechanism analysis with static and dynamic state system results showed that loads of total nitrogen (TN) and total phosphorous (TP) during rainfall are greatly increased than non-rainfall, which will aggravate the pollution load of the water system. Accordingly, the sewer outflow in pipe network is analyzed due to the increased flow and inflow of pollutant concentration caused by rainfall. The proposed sewer network monitoring and fault diagnosis technique can be used effectively for the nonpoint source pollution management of the urban watershed as well as continuous monitoring system.

• The Journal of Korean Academy of Prosthodontics
• /
• v.47 no.1
• /
• pp.53-60
• /
• 2009

Statement of problem: At present, as the esthetic demands are on the increase, there are many ongoing studies for tooth-colored post and cores. Most of them are about fiber post and prefabricated zirconia post, but few about one-piece milled zirconia post and core using CAD/CAM (computer-aided design/computer-aided manufacturing) technique. Purpose: The objective of this study was to compare microleakage of endodontically treated teeth restored with three different tooth-colored post and cores. Material and methods: Extracted 27 human maxillary incisors were cut at the cementoenamel junction, and the teeth were endodontically treated. Teeth were divided into 3 groups (n=9); restored with fiber post and resin core, prefabricated zirconia post and heat-pressed ceramic core, and CAD/CAM milled zirconia post and core. After the preparation of post space, each post was cemented with dual-polymerized resin cement (Variolink II). Teeth were thermocycled for 1000 cycles between $5-55^{\circ}C$ and dyed in 2% methylene blue at $37^{\circ}C$ for 24 hours. Teeth were sectioned (bucco-lingual), kept the record of microleakage and then image-analyzed using a microscope and computer program. The data were analyzed by one-way ANOVA and Scheffe's multiple range test (${\alpha}=0.05$). Results: All groups showed microleakage and there were no significant differences among the groups (P>.05). Prefabricated zirconia post and heat-pressed ceramic core showed more leakage in dye penetration at the post-tooth margin, but there was little microleakage at the end of the post. Fiber post and resin core group and CAD/CAM milled zirconia post and core group indicated similar microleakage score in each stage. Conclusion: Prefabricated zirconia post and heat-pressed ceramic core group demonstrated better resistance to leakage, and fiber post and resin core group and CAD/CAM milled zirconia post and core group showed the similar patterns. The ANOVA test didn't indicate significant differences in microleakage among test groups. (P>.05)

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.3
• /
• pp.474-480
• /
• 2004

The purpose of this in vitro study was to compare the remineralizing effects of three glass ionomer cements (high filled glass ionomer cement, compomer, resin modified glass ionomer cement) with resin composite (control group) on incipient interproximal caries, and to assess long-term change of remineralization effect, in each material, evaluated by microtomography. Proximal restoration was simulated with tooth specimen and Glass Ionomer Cements. And each of these groups was placed into a closed container with artificial saliva at $37^{\circ}C$ and pH 7.0 for a time period of thirty days with constant circulation. At the end of thirty and sixty days, tomographic images were taken from these specimens with micro CT scanner. Materials used in this study were as follows. Group 1: Fuji IX GP (GC Corp., Tokyo, Japan) Group 2: Vitremer (3M ESPE, St. Paul, Minn., USA) Group 3: F2000 (3M ESPE, St. Paul, Minn., USA) Group 4: Z250 (3M ESPE, St. Paul, Minn., USA) Using density-measuring program, the micro-density of carious lesions on the specimens were measured. The mean density changes of each group were compared to the other groups to evaluate the effect of remineralization. The results were as follows: 1. The lesion density of all groups increased. 2. The mean density increase of Group 1, 2, 3 were higher than that of Group 4 every month(p<0.05). 3. There were significant differences of density increase among glass ionomer group(Group 1, 2, 3).

• Journal of Gastric Cancer
• /
• v.5 no.2
• /
• pp.95-100
• /
• 2005

Purpose: Critical pathways (CP), also known as clinical pathways, are management plans that display goals for patients and have led to improved outcomes for many disease entities. This study was aimed at developing a critical pathway for the surgical treatment of gastric cancer patients and evaluating its usefulness. Materials and Methods: A CP was developed and implemented by a team of surgeons, nurses, nutritionists, and administrative officials. Among the 117 patients who received curative gastrectomies for gastric cancer at Kangnam St. Mary's Hospital, The Catholic University of Korea, between October 2003 and August 2004, 26 patients were treated according to the CP. We evaluated its usefulness by comparing the clinical characterisctics, postoperative progress, hospital stays, and costs between the CP and the non-CP groups. Patient satisfaction was also surveyed with questionnaires. Results: Of the initial 26 patients in the CP group, two were excluded from the final evaluation; one patient had a duodenal stump leakage, and the other had a gastric stasis postoperatively. In 8 patients, protocol violation occurred; six patients refused to be discharged on the $7^{th}$ postoperative day, one patient who had an gastric staisis postoperatively stayed for 2 additional days, and one patient who needed ICU care stayed for 4 additional days. The drop-out rate was $7.7\%$ (2/26), and the variance rate was $30.8\%$ (8/26). The mean hospital stay was 11.3 days ($10\~15$ days) for the CP group compared with 17.5 days ($9\∼68$ days) for the non-CP group, resulting in a difference of about 6 days (P<0.05). The mean hospital stays after surgery were 10.3 days ($7\∼68$ days) and 8.3 days ($7\∼12$ days) for the non-CP and the CP groups, respectively, but the difference was statistically not significant (P>0.05). The mean charge during the hospital stay was higher in the non-CP group ( $\\$ 6,292,200) than in the CP group ( $\\$ 4,863,685). The charge per hospital day was higher in the CP group ( $\\$ 430,414) than in the non-CP group ( $\\$ 359,554). Patient satisfaction was higher in the CP group than in the non-CP group. Conclusion: By developing and applying a critical pathway in the surgical treatment of stomach cancer patients, we could reduce the length of hospital stay as well as the cost. A multi-centered prospective study to establish a standard treatment pathway and to demonstrate its effectiveness is needed in the future.

• Progress in Medical Physics
• /
• v.24 no.2
• /
• pp.85-91
• /
• 2013

At present, megavoltage computed tomography (MVCT) is the only method used to correct the position of tomotherapy patients. MVCT produces extra radiation, in addition to the radiation used for treatment, and repositioning also takes up much of the total treatment time. To address these issues, we suggest the use of a video image-guided setup (VIGS) system for correcting the position of tomotherapy patients. We developed an in-house program to correct the exact position of patients using two orthogonal images obtained from two video cameras installed at $90^{\circ}$ and fastened inside the tomotherapy gantry. The system is programmed to make automatic registration possible with the use of edge detection of the user-defined region of interest (ROI). A head-and-neck patient is then simulated using a humanoid phantom. After taking the computed tomography (CT) image, tomotherapy planning is performed. To mimic a clinical treatment course, we used an immobilization device to position the phantom on the tomotherapy couch and, using MVCT, corrected its position to match the one captured when the treatment was planned. Video images of the corrected position were used as reference images for the VIGS system. First, the position was repeatedly corrected 10 times using MVCT, and based on the saved reference video image, the patient position was then corrected 10 times using the VIGS method. Thereafter, the results of the two correction methods were compared. The results demonstrated that patient positioning using a video-imaging method ($41.7{\pm}11.2$ seconds) significantly reduces the overall time of the MVCT method ($420{\pm}6$ seconds) (p<0.05). However, there was no meaningful difference in accuracy between the two methods (x=0.11 mm, y=0.27 mm, z=0.58 mm, p>0.05). Because VIGS provides a more accurate result and reduces the required time, compared with the MVCT method, it is expected to manage the overall tomotherapy treatment process more efficiently.

• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.1
• /
• pp.72-78
• /
• 2009

Purpose: Bone mineral density (BMD) measurements need to be precise enough to be capable of detecting small changes in bone mass of rats. Using a regular dual-energy X-ray absorptiometry (DXA), we measured many BMD of various skeletal sites in rats to examine precision of DXA in relation to the repositioning on the bones of rats. Materials and Methods: Using DXA and small animal software, scans were performed 4 times in all 12 male rats without repositioning (Group 1a). Another four scans for 6 of 12 rats were done with repositioning between scans (Group 2). Customized regions of interest (ROIs), encapsulate the right hind limb, L1-4, skull and pelvic bones were drawn at each measurement. The precision of the measurements was evaluated by measuring the coefficient of variation (CV) of four measurements of BMD at each skeletal site of all rats with or without repositioning. Significance of differences between group 1b (six rats out of group 1a, which were come under group 2) and group2 were evaluated with Wilcoxon Signed Rank Sum Test. Results: CVs obtained at different skeletal sites of all measurements in Group 1b and 2. It was $3.51{\pm}1.20$, $ 2.62{\pm}1.20$ for the hindlimb (p=0.173), $3.83{\pm}2.02$, $4.59{\pm}2.02$ for L1-4 (p=0.600), $3.73{\pm}1.87$, $1.53{\pm}0.89$ for skull (p=0.046), and $2.92{\pm}0.60$, $1.45{\pm}0.60$ for pelvic bones (p=0.075). Conclusion: Our study demonstrates that the DXA technique has the precision necessary when used to assess BMD for various skeletal sites in rats regardless of repositioning.

• Journal of the Korean Arthroscopy Society
• /
• v.15 no.2
• /
• pp.99-107
• /
• 2011

Purpose: The purpose of this study was to investigate the clinical results after a anatomical double bundle ACL reconstruction using a longitudinally split tibialis anterior allograft. Materials and Methods: We evaluated 24 patients with a minimum follow-up of 12 months who had undergone anatomical double bundle ACL reconstructions. The grafts utilized in all cases were tibialis anterior allografts which were longitudinally split into two strands. A standard rehabilitation protocol was applied in all patients. The pre- and post-operative data including Lysholm scores, International Knee Documentation Committee (IKDC) scores, Lachman test, pivot shift test and the side-to-side differences of anterior laxity measured by KT-2000 arthrometer were analyzed by use of a statistical method Results: The mean side-to-side instrumented laxity measured by the KT-2000 arthrometer significantly improved to a mean of $1.04{\pm}0.80\;mm$ (P < 0.001). The Lysholm knee scores also improved from $58.34{\pm}15.32$ to $86.25{\pm}6.48$ after surgery (P < 0.001). The patients exhibited improved IKDC scores (A: 15 cases, B; 9 cases) at the final follow-up, compared to preoperative scores (B: 5, C: 10, D: 9). Conclusion: Our data demonstrated that clinical results of anatomical double bundle ACL reconstruction with a split tibialis anterior allograft are encouraging with excellent side-to side laxity, significantly improved Lysholm knee score, IKDC score, Lachman and pivot shift data.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.12 no.2
• /
• pp.256-262
• /
• 2001

Objective：The enlargement of the lateral ventricle is well established finding in adult-onset schizophrenia, but in the patients with early-onset psychotic disorder(EOPD) is still controversal. To identify structural abnormalities of the lateral ventricle in patients with EOPD and difference of the brain developmental course in EOPD group, planimetrical assessment of the lateral ventricle was conducted by means of retrospective quantitative neuroimaging. Methods：The brain MR images of 14 patients with EOPD(mean age $14.0{\pm}2.1$ years) who met the DSM-III-R diagnostic criteria for schizophrenia and bipolar disorder and 24 control subjects with simple headache(mean age $10.0{\pm}2.1$ years) were collected. Single best view for the lateral ventricle, one axial slice was selected for analysis. MR images were redigitalized with flatbed scanner and data were analyzed with NIH IMAGE software. Results：In the patients with EOPD, there were significant correlations between aging and lateral ventricular sizes and between aging and ventricular brain ratio(VBR). The statistical significance of normal asymmetry of the lateral ventricle was not observed for the EOPD group. The EOPD group had larger lateral ventricular sizes and VBR than control group, but these results were not statistically significant. Conclusion：These findings suggest that the brain abnormalities in patients with EOPD progress from the earlier course of the disorders and the course of brain development in EOPD group is different from control group.

• Journal of Hospice and Palliative Care
• /
• v.5 no.2
• /
• pp.125-135
• /
• 2002

Purpose : The purpose of this study was to investigate the impact of depression, discomfort, spirituality, physical care, and opioid use on pain with terminally ill cancer patients in the hospice units. Method : The convenient sample of this study consisted of 58 terminally ill cancer patients at three hospice units in university-affiliated hospitals. Patients were interviewed with structured questionnaires. The data was analyzed using ANOVA, Pearson correlation coefficient, and multivariate multiple regression. Result : The results of this study were as follows : 1) The mean age of the participants was approximately 57 years. Regarding diagnosis, stomach cancer showed the highest frequency (24.1%), followed by lung cancer (17.2%) and rectal cancer (13.8%). Regarding motivation for admission to the hospice unit, the majority of the participants indicated pain control (67.2%), followed by spiritual care (39.7%), and symptom relief (27.6%). 2) The mean pain level measured by VAS was 5.13 (${\pm}2.61$). Regarding pain type, the highest pain frequency the participants experienced was deep pain (53.4%), followed by multiple pain (20.7%), intestinal pain (17.3%), and neurogenic (5.2%) and superficial pain (3.4%). 3) Regarding the factors influencing pain, the pain level was significantly affected by the depression level (P<0.01) and the opioid use (P<0.01). Conclusion, In summary, the higher the level of pain the terminally ill cancer patents had the higher the depression level as well as the opioid use. Thus, health care professionals need to continuously provide holistic care for them to die comfortably.

• Journal of Internet Computing and Services
• /
• v.18 no.1
• /
• pp.105-119
• /
• 2017

Smartphone users hit over eighty-five percentage of Korean populations and personal private items and various information are stored in each user's smartphone. There are so many cases to propagate malicious codes or spywares for the purpose of catching illegally these kinds of information and earning pecuniary gains. Thus, need of information security is outstanding for using smartphone but also user's security perception is important. In this paper, we investigate about how information security affects smartphone operating system choices by users. For statistical analysis, the online survey with questionnaires for users of smartphones is conducted and effective 218 subjects are collected. We test hypotheses via communalities analysis using factor analysis, reliability analysis, independent sample t-test, and linear regression analysis by IBM SPSS statistical package. As a result, it is found that hardware environment influences on perceived ease of use. Brand power affects both perceived usefulness and perceived ease of use and degree of personal risk-accepting influences on perception of smartphone spy-ware risk. In addition, it is found that perceived usefulness, perceived ease of use, degree of personal risk-accepting, and spy-ware risk of smartphone influence significantly on intention to purchase smartphone. However, results of independent sample t-test for each operating system users of Android or iOS do not present statistically significant differences among two OS user groups. In addition, each result of OS user group testing for hypotheses is different from the results of total sample testing. These results can give important suggestions to organizations and managers related to smartphone ecology and contribute to the sphere of information systems (IS) study through a new perspective.