• Journal of Preventive Medicine and Public Health
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• v.49 no.2
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• pp.108-117
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• 2016

Objectives: Smoking is known to be associated with nephropathy in patients with diabetes. The distinct effects of smoking before and after diabetes has been diagnosed, however, are not well characterized. We evaluated the association of cigarette smoking before and after a diagnosis of diabetes with the presence of diabetic nephropathy. Methods: We analyzed data from the 2011-2013 editions of the Korea National Health and Nutrition Examination Survey. A total of 629 male patients diagnosed with diabetes were classified as non-smokers (90 patients), former smokers (225 patients), or continuing smokers (314 patients). A "former smoker" was a patient who smoked only before receiving his diagnosis of diabetes. A "continuing smoker" was a patient who smoked at any time after his diabetes had been diagnosed. Diabetic nephropathy was defined as the presence of albuminuria (spot urine albumin/creatinine ratio ${\geq}30mg/g$) or low estimated glomerular filtration rate ($<60mL/min/1.73m^2$). Multiple logistic regression models were used to assess the independent association after adjusting for age, duration of diabetes, hemoglobin A1c, body mass index, systolic blood pressure, medication for hypertension, and medication for dyslipidemia. Female patients were excluded from the study due to the small proportion of females in the survey who smoked. Results: Compared to non-smokers, continuing smokers had significantly higher odds ratio ([OR], 2.17; 95% confidence interval [CI], 1.23 to 3.83) of suffering from diabetic nephropathy. The corresponding OR (95% CI) for former smokers was 1.26 (0.70 to 2.29). Conclusions: Smoking after diagnosis of diabetes is significantly associated with the presence of diabetic nephropathy in the Korean male population.

• Journal of Preventive Medicine and Public Health
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• v.41 no.1
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• pp.51-60
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• 2008

Objectives : We examined the effect of sociodemographic factors, cancer, and psychiatric disorders on suicide by gender and age-specific patterns in South Korea. Methods : The study is a case-control study. Claim data was obtained from the national health insurance database and national death registration database. The number of people who committed suicide was 11,523, which was matched with a control group consisting of ten times as many people at 115,230 selected from the national health insurance and medical aids beneficiaries. The medical utilization of the case group was one year before death and that of the control group was from July 1,2003 to June 30, 2004. Four variables-address, economic status, presence of a psychiatric disease, and cancer-were used in multiple logistic regression analyses. Results : Living in cities or in rural areas showed a greater risk for suicide than living in a metropolitan city. Low economic status, the presence of a psychiatric disorder, and cancer were also statistically meaningful risk factors for suicide. The three major psychiatric diseases, schizophrenia, alcohol abuse, and bipolar disorder, were meaningful in all age groups, but the scale of the odds ratio differed by the age group. Only the psychiatric disorder variable was meaningful in the adolescent group, whereas a psychiatric disorder and economic status were meaningful for the young adult group, and all variables were meaningful for the middle-aged group. A psychiatric disorder and cancer were meaningful in the elderly group, economic status was meaningful for male subjects, and address was meaningful for female subjects. Conclusions : Factors such as living in city or rural areas, low economic status, the presence of a psychiatric disorder, and cancer were statistically meaningful risk factors in suicide. These factors also differed by age group. Therefore, policymakers should establish policies for suicide prevention that are relevant for each age group.

• Journal of Digital Convergence
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• v.20 no.3
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• pp.431-438
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• 2022

With the technical development of fourth industrial revolution, VR game market is rapidly expanding. Meanwhile, heavy user group means the group consisting of people consuming certain media or contents more than others, which is the core constituency of the media industry, and there have been only a few studies on them. This study identified the factors that influenced the continuous intention of use of VR game heavy users and figured out their characteristics by verifying the difference in variables with the light user group. According to the results, the heavy user group showed higher behaviors than the light user group in terms of personal innovation, presence, and continuous intention of use variables. In addition to this, it was found that personal innovation, perceived quality, and presence had a significant influence on the continuous intention of use. This study is intended to empirically analyze the characteristics of heavy VR game users and influential factors, thereby preparing baseline data for VR game development and other relevant studies.

• Restorative Dentistry and Endodontics
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• v.47 no.3
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• pp.34.1-34.12
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• 2022

Objectives: This study aimed to evaluate the success rate of endodontic treatments performed by undergraduate students and the factors associated with the outcome. Materials and Methods: A follow-up of 3 to 8 years after root canal filling was carried out in 91 patients. At the follow-up visits, medical and dental history questionnaires were applied along with clinical and radiographic examinations. Data collected in the clinical exam included: the presence of pain, swelling, sinus tract, mobility, tenderness to palpation and percussion, periodontal probing profile, and type/quality of coronal restoration. Postoperative and follow-up radiographs were digitalized and analyzed by 2 trained and calibrated examiners to assess periapical healing. The treatment outcome was based on strict clinical and radiographic criteria and classified as success (absence of any clinical and radiographic sign of apical periodontitis) or failure (other combination). Logistic regression was used to investigate the impact of clinical and radiographic variables on endodontic treatment outcomes at a 5% significance level. Results: The success rate of endodontic treatments was 60.7%. The only risk factor significantly associated with failure was the presence of a periapical lesion on the postoperative radiograph (odds ratio, 3.35; 95% confidence interval, 1.17-9.54). Conclusions: The success rate of endodontic treatments performed by undergraduate students was low and was jeopardized by the presence of a periapical lesion on the postoperative radiograph.

• Childhood Kidney Diseases
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• v.28 no.1
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• pp.35-43
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• 2024

Purpose: Recurrent urinary tract infections (UTIs) in children is a major challenge for pediatricians. This study was designed to investigate the risk factors for recurrent UTIs and determine the association between recurrent UTIs and clinical findings, including growth patterns in infants and children younger than 24 months of age. Methods: We retrospectively reviewed the medical records of 147 patients <24 months of age with UTIs who were hospitalized between August 2018 and October 2021. The patients were divided into recurrent and single UTI episode groups. Clinical findings and anthropometric and laboratory data were compared between the two groups. Results: In the recurrent UTI group, the weight-for-length (WFL) percentile at the first UTI diagnosis was lower compared to the single UTI episode group, and the weight-for-age percentile at 3-month and 6-month follow-ups after the first UTI decreased (all P<0.05). In univariable logistic regression analysis, higher birth weight, lower WFL percentile, the presence of hydronephrosis, acute pyelonephritis or vesicoureteral reflux, the use of prophylactic antibiotics, and non-Escherichia coli infections were associated with the development of recurrent UTIs (all P<0.05). However, in the multivariable analysis, only the presence of hydronephrosis and prophylactic antibiotic use were independently related to UTI recurrence (P<0.05). Conclusions: The presence of hydronephrosis at the first UTI can be helpful for predicting UTI recurrence in young children aged <24 months. Antibiotic prophylaxis may be associated with UTI recurrence. Potential growth delay should be carefully monitored in infants with recurrent UTI.

• Journal of Computing Science and Engineering
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• v.5 no.4
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• pp.294-304
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• 2011

Enhancing continuous queries over data streams with temporal functions and predicates enriches the expressive power of those queries. While traditional continuous queries retrieve only the values of attributes, temporal continuous queries retrieve the valid time intervals of those values as well. Correctly evaluating such queries requires the coalescing of adjacent timestamps for value-equivalent tuples prior to evaluating temporal functions and predicates. For many stream applications, the available computing resources may be too limited to produce exact query results. These limitations are commonly addressed through load shedding and produce approximated query results. There have been many load shedding mechanisms proposed so far, but for temporal continuous queries, the presence of coalescing makes theses existing methods unsuitable. In this paper, we propose a new accuracy metric and load shedding algorithm that are suitable for temporal query processing when memory is insufficient. The accuracy metric uses a combination of the Jaccard coefficient to measure the accuracy of attribute values and $\mathcal{PQI}$ interval orders to measure the accuracy of the valid time intervals in the approximate query result. The algorithm employs a greedy strategy combining two objectives reflecting the two accuracy metrics (i.e., value and interval). In the performance study, the proposed greedy algorithm outperforms a conventional random load shedding algorithm by up to an order of magnitude in its achieved accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.12
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• pp.5149-5173
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• 2016

Cooperative forwarding has shown a substantial network performance improvement compared to traditional routing in multi-hop wireless network. To further enhance the system throughput, especially in the presence of highly congested multiple cross traffic flows, a promising way is to incorporate the multi-radio multi-channel (MRMC) capability into cooperative forwarding. However, it requires to jointly address multiple issues. These include radio-channel assignment, routing metric computation, candidate relay set selection, candidate relay prioritization, data broadcasting over multi-radio multi-channel, and best relay selection using a coordination scheme. In this paper, we propose a simple and efficient cluster-based cooperative data forwarding (CCDF) which jointly addresses all these issues. We study the performance impact when the same candidate relay set is being used for multiple cross traffic flows in the network. The network simulation shows that the CCDF with MRMC not only retains the advantage of receiver diversity in cooperative forwarding but also minimizes the interference, which therefore further enhances the system throughput for the network with multiple cross traffic flows.

• Smart Structures and Systems
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• v.17 no.6
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• pp.903-915
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• 2016

The classical Kalman filter (KF) provides a practical and efficient state estimation approach for structural identification and vibration control. However, the classical KF approach is applicable only when external inputs are assumed known. Over the years, some approaches based on Kalman filter with unknown inputs (KF-UI) have been presented. However, these approaches based solely on acceleration measurements are inherently unstable which leads poor tracking and so-called drifts in the estimated unknown inputs and structural displacement in the presence of measurement noises. Either on-line regularization schemes or post signal processing is required to treat the drifts in the identification results, which prohibits the real-time identification of joint structural state and unknown inputs. In this paper, it is aimed to extend the classical KF approach to circumvent the above limitation for real time joint estimation of structural states and the unknown inputs. Based on the scheme of the classical KF, analytical recursive solutions of an improved Kalman filter with unknown excitations (KF-UI) are derived and presented. Moreover, data fusion of partially measured displacement and acceleration responses is used to prevent in real time the so-called drifts in the estimated structural state vector and unknown external inputs. The effectiveness and performance of the proposed approach are demonstrated by some numerical examples.

• Smart Structures and Systems
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• v.18 no.3
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• pp.375-387
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• 2016

The classical Kalman filter (KF) can provide effective state estimation for structural identification and vibration control, but it is applicable only when external inputs are measured. So far, some studies of Kalman filter with unknown inputs (KF-UI) have been proposed. However, previous KF-UI approaches based solely on acceleration measurements are inherently unstable which leads to poor tracking and fictitious drifts in the identified structural displacements and unknown inputs in the presence of measurement noises. Moreover, it is necessary to have the measurements of acceleration responses at the locations where unknown inputs applied, i.e., with collocated acceleration measurements in these approaches. In this paper, it aims to extend the classical KF approach to circumvent the above limitations for general real time estimation of structural state and unknown inputs without using collocated acceleration measurements. Based on the scheme of the classical KF, an improved Kalman filter with unknown excitations (KF-UI) and without collocated acceleration measurements is derived. Then, data fusion of acceleration and displacement or strain measurements is used to prevent the drifts in the identified structural state and unknown inputs in real time. Such algorithm is not available in the literature. Some numerical examples are used to demonstrate the effectiveness of the proposed approach.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.5 no.2
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• pp.269-279
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• 1998

In nursing research that the data is collected through clinical observation, analysis of clinical recording or coding of interpersonal interaction in clinical areas, testing and reporting interrater reliability is very important to assure reliable results. Procedures for interrater reliability in these studies should follow two steps. The first step is to determine unitizing reliability, which is defined as consistency in the identification of same data elements in the record by two or more raters reviewing the same record. Unitizing reliability have been rarely reported in previous studies. Unitizing reliability should be tested before progressing to the next step as precondition. Next step is to determine interpretive reliability. Cohen's kappa is a preferable method of calculating the extent of agreement between observer or judges because it provides beyond-chance agreement. Despite its usefulness, kappa can sometimes present paradoxical conclusions and can be difficult to interpret. These difficulties result from the feature of kappa which is affected in complex ways by the presence of bias between observers and by true prevalence of certain categories. Therefore, percentage agreement should be reported with kappa for adequate interpretation of kappa. The presence of bias should be assessed using the bias index and the effect of prevalence should be assessed using the prevalence index. Researchers have been reported only global reliability reflecting the extent to which coders can consistently use the whole coding system across all categories. Category-by-category reliability also need to be reported to inform the possibility that some categories are harder to use than others.