• Quality Improvement in Health Care
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• v.15 no.2
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• pp.107-120
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• 2009

Background : To estimate fall incidence rate and associated factors in inpatients from a general hospital. Method : The data were collected from 104 fall incident reports developed by the patient safety committee in a general hospital in Seoul from 01 January 2007 to 31 December 2008. Information included general characteristics of patients, factors related to fall, types, places, circumstances and outcomes of fall. Result : The incidence rate of fall, which was 4.4 per 1,000 total discharged patients and 0.5 per 1,000 patient-days, was much lower than that of several hospitals in the United States. The difference may reflect the different incidence reporting system of each hospital. Fall-prone patients were, in general, $$\geq_-$$65 years of age, had an alert mental status, were ambulatory with some assistance, and were dependent on and ambulatory device. High incidence of falls was associated with patients with circulatory disease. The majority of fall events usually occurred in bed or at the bedside in the patient's room, and occurred more often during the night than during the day or evening. Risk factors of fall were use of drugs (antihypertensive or neuropsychiatric drugs) and environmental factors (e.g., overly high bed height, surrounding objects, inadequate fitness shoes and slippery floor). Physical injury occurred in 43.3% of fall events, which typically required diagnosis of injury and treatment such as suturing. Risk factors for repeated falls were use of a neuropsychiatric drug (odds ratio=13.9) and gait disturbance (odds ratio=91.2). Risk factors for fall-related injury were alert mental status (odds ratio=3.3 times more likely to fall than those who were drowsy or in a stupor) and general weakness(odds ratio=3.3 times more likely to fall than those who were not generally weak). Conclusion : Medical and nursing staff should be aware of the fall risk factors of hospitalized patients and should intensively pursue preventative strategies. Development of fall prevention education based on these results is recommended.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.3
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• pp.183-190
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• 2002

This paper describes the synthesis of robust and non-fragile H$\infty$ state feedback controllers for linear varying systems with affine parameter uncertainties, and static state feedback controller with structured uncertainty. The sufficient condition of controller existence, the design method of robust and non-fragile H$\infty$ static state feedback controller, and the set of controllers which satisfies non-fragility are presented. The obtained condition can be rewritten as parameterized Linear Matrix Inequalities(PLMls), that is, LMIs whose coefficients are functions of a parameter confined to a compact set. However, in contrast to LMIs, PLMIs feasibility problems involve infinitely many LMIs hence are inherently difficult to solve numerically. Therefore PLMls are transformed into standard LMI problems using relaxation techniques relying on separated convexity concepts. We show that the resulting controller guarantees the asymptotic stability and disturbance attenuation of the closed loop system in spite of controller gain variations within a degree.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.179-190
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• 2020

As the business environment is rapidly changing with globalization and complexity of information flows, the uncertainty is also very increased for project environment. Although many studies have been conducted to find out the critical factors for project success, there still exist different views to define project success. Furthermore, implementing success formula for one project does not necessarily guarantee a success for another project since there are other elements that impede the success of project. In this regards, it is imperative to examine what are the barriers to project success. This study aims to examine the barriers that impede the success of project. Past literature was thoroughly reviewed to collect and develop a preliminary list of elements that affected project performance negatively. Experts were interviewed to refine the list and the final list of the measurement items were developed. A survey questionnaire was developed with the final list of measurement items, and a survey was conducted on the practitioners with project experience. After the survey, an exploratory factor analysis was conducted on the final list to extract the component dimensions which in turn formed the group of project barriers. The exploratory factor analysis provided ten factors, which are difficulty of process management, failure of project feasibility analysis, cost overruns and lack of cost benefits, unclarity project plan, strategic consistency error, stakeholder conflict, inaccuracy of requirement definition, disturbance of communication, technical environment change, negative attitude of top management.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.499-504
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• 2000

Amelogenesis imperfecta is defined as a genetically determined effect affecting enamel formation and may be associated with other ectodermal or systemic disorders. It is entirely an ectodermal disturbance, since the mesodermal components of the teeth are basically normal. The presentation of diverse clinical manifestations in 1:14,000 to 1:16,000. Classification of the AI types considers mode of inheritance and clinical manifestations. The most widely accepted classification system recognize three major groups; i.e., hypoplastic(thin enamel), hypocalcified(primary mineralization defect), hypomaturation(defect in enamel maturation). The treatment is that at first, genetic counselling must be practiced, and in anterior teeth, composite resin veneer or jacket crown for esthetics, and in posterior teeth, stainlees steel crown or gold onlay.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.3
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• pp.334-341
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• 2003

In this paper, we proposed a recurrent time delayed neural network(RTDNN) controller which compensate a output of neural network controller. Even if learn by neural network controller, it can occur an bad results from disturbance or load variations. So in order to adjust above case, we used the fuzzy compensator to get an expected results. And the weight of main neural network can be changed with the result of learning a inverse model neural network of plant, so a expected dynamic characteristics of plant can be got. As the results of simulation through the second order plant, we confirmed that the proposed recurrent time delayed neural network controller get a good response compare with a time delayed neural network(TDU) controller. We implemented the controller using the DSP processor and applied in a hydraulic servo system. And then we observed an experimental results.

• Korean Journal of Biological Psychiatry
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• v.14 no.2
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• pp.106-114
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• 2007

Objective : It is suggested that disturbance of dopaminergic system might be related to the possible mechanism of social phobia. The aim of this study was to investigate the possible association of DRD2 TaqI polymorphism and social phobia. Method : Fifty-one patients with social phobia and 200 comparison subjects were tested for DRD2 TaqI A polymorphism. The severity of social phobic symptoms was measured by self-report version of the Liebowitz Social Anxiety Scale(LSAS-SR) and Hamilton anxiety scale(HAM-A). Results : There was no signigicant difference in the genotype, allele frequency, A1 carrier frequency, and heterozygote frequency DRD2 TaqI A polymorphism between the social phobia patients and the control groups. However, we found significant decrease in somatic anxiety of the HAM-A in the patients having A2A2 homozygotes(p=0.014). In addition, patients having A1A2 heterozygotes showed more anxiety in two subscales (p=0.042 in anxiety, p=0.019 in performance) of the LSAS-SR. Conclusion : These results suggest that DRD2 A2 homozygote might have a protective role against somatic anxiety, and molecular heterosis of DRD2 TaqI A polymorphism might be related with more severe anxiety in social phobia.

• Korean Journal of Cleft Lip And Palate
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• v.4 no.2
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• pp.69-78
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• 2001

Alveolar cleft exists in 75% of cleft patients, In alveolar cleft patients, alar base is widening, palatal fistular formation, maxillary growth disturbance & tooth loss of adjacent area is raised, Alveolar bone grafting, especially iliac bone grafting, is a general treatment method. As operation timing, bone grafting is classified with primary, early secondary, secondary, & late secondary, Here we report cleft width, marginal bone height, bone resorption rate, grafted shape & bone densities after secondary iliac bone grafting was done in the Dept. of oral and maxillofacial surgery of chonbuk national university hospital. We compared cleft width to bone resorption rate and grafted shape. Also, alveolar bone densities of grafted and contralateral site was compared with Emago 3 package? (Oral Diagonostic System, The Netherlands), The data obtained were analyzed using Spearman's rho coefficients and sign test with SPSS for window, The results were obtained as follows. 1. As alveolar cleft width is increase, bone resorption rate is, too. This relation showed significant difference(P<.01). 2, In proximal & distal area, alvolar cleft width and bone graft contour after bone grafting had a reverse proportional difference. It was not significant difference(P>.05). 3. After 3 month, in bone density results by using Emago 3 package? with periapical standard view, occlusal view & panoramic view, differences between grafted bone and alveolar bone of contralateral site didn't show a significant difference(P>.05). Thus, differences of bone densities in the alveolar bones didn't exist.

• Archives of Pharmacal Research
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• v.18 no.3
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• pp.183-188
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• 1995

Polymeric reinforcement and coatings of alginate beads were carried out to control the release rate of drug from alginate beads. A poorly water-soluble ibuprofen (IPF) was selected as a model drug. A commercially available $Eudragit^{\circledR}$ RS100 was also used as a polymer. Effects of polymeric contents, the presence of plasticizers and amount of drug loading on the release rate of drug were investigated. The release rate of drug from alginate beads in the simulated gastric fluid did not occur within 2 h but released immediately when dissolution media were switched to the simulated intestinal fluid. No significant difference of release rate from polymer-reinforced alginate bead without plasticizers was observed when compared to plain (simple) beads. However, the release rate of drug from polymer-reinforced alginate beads was further sustained and retarded when aluminium tristearate (AT) as a plasticizer was added to polymer. However, polyethylene glycol 400 (PEG400) did not change the release rate of drug from alginate beads although PEG400 was used to improve dispersion of polymer and sodium alginate, and plasticize $Eudragit^{\circledR}$ RS100 polymer. The presence of plasticizer was crucial to reinforce alginate gel matrices using a polymer. As the amount of drug loading increased, the release rate of drug increased as a result of decreasing effects of polymer contents in matrices. The significantly sustained release of drug from polymer-coated alginate beads occurred as the amount of polymer increased because the thickness of coated membrane increased so that cracks and pores of the outer surface of alginate beads could be reduced. The sustained and retarded action of polymer-reinforced and coated beads may result from the disturbance of swelling and erosion (disintegration) of alginate beads. From these findings, polymeric-reinforcement and coatings of alginate gel beads can provide an advanced delivery system by retarding the release rate of various drugs.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.737-742
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• 2011

Navigation problems include the task of determining the control input under various constraints for systems such as mobile robots subject to uncertain disturbance. Such tasks can be modeled as constrained stochastic control problems. In order to solve these control problems, one may try to utilize the dynamic programming(DP) methods which rely on the concept of optimal value function. However, in most real-world problems, this trial would give us many difficulties; for examples, the exact system model may not be known; the computation of the optimal control policy may be impossible; and/or a huge amount of computing resource may be in need. As a strategy to overcome the difficulties of DP, one can utilize ADP(approximate dynamic programming) methods, which find suboptimal control policies resorting to approximate value functions. In this paper, we apply recently proposed ADP methods to a class of navigation problems having complex constraints, and observe the resultant performance characteristics.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.4
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• pp.532-538
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• 2012

The aim of this study was to find correlation between EGG and HRV parameters in dyspeptic patients. 39 patients (male 8, female 31) were enrolled. EGG and HRV was measured in all patients. EGG parameters like % of gastric slow wave and power ratio were used to classify patients as normal or abnormal EGG groups. HRV parameters which were included TP (total power), LF(low frequency density), HF (high frequency density), and LF/HF ratio were compared between them. EGG parameters were compared among normal, sympathetic hyperactivity, and parasympathetic hyperactivity groups classified by LF/HF ratio. There was no difference in HRV parameters between normal and abnormal EGG groups. Comparing EGG parameters among normal, sympathetic hyperactivity, and parasympathetic hyperactivity groups, both sympathetic and parasympathetic hyperactivity groups had lower value of postprandial regularity of gastric slow wave than normal group. Abnormal value of LF/HF ratio(both sympathetic and parasympathetic hyperactivity) may be related with disturbance of electrical gastric activity in patients with dyspepsia.