• Bulletin of the Korean Mathematical Society
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• v.52 no.4
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• pp.1241-1252
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• 2015

In this paper, we study the dynamical bifurcation of the modified Swift-Hohenberg equation on a periodic interval as the system control parameter crosses through a critical number. This critical number depends on the period. We show that there happens the pitchfork bifurcation under the spatially even periodic condition. We also prove that in the general periodic condition the equation bifurcates to an attractor which is homeomorphic to a circle and consists of steady states solutions.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.463-468
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• 2002

This study investigates the variations of shear force, displacement, and fracture surface with the shear speed and the number of reflows. The experimental data of shear tests indicate that the shear force increases as increasing the number of reflows and the shear speed due to the formation of a kind of intermetallic compound, Ni$_3$Sn$_4$, on Au/Ni/Cu pad, and the work-hardening. However, general trends show that the shear force decreases due to increasing the thickness of the intermetallic compound over 4x reflow. It is observed that the intermetallic compound which is formed between solder and pad increases according to increasing the number of reflows, and the growth rate of the intermetallic compound at central region on the interface is faster than one at edge part. The general tendencies of shear force and displacement with different shear speeds are almost identical as an increase of the number of reflows.

• Bulletin of the Korean Mathematical Society
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• v.43 no.4
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• pp.763-770
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• 2006

Let X be a four-dimensional projective variety defined over the field of complex numbers with only terminal singularities. We prove that if the intersection number of the canonical divisor K with every very general curve is positive (K is almost numerically positive) then every very general proper subvariety of X is of general type in ';he viewpoint of geometric Kodaira dimension. We note that the converse does not hold for simple abelian varieties.

• Knowledge Management Research
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• v.16 no.1
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• pp.209-224
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• 2015

Previous studies provided that limiting the number of services provided in hospital had influences in decreasing cost in delivering medical services. Hospitals could have positive effects on their profit by concentrating small number of services which they have comparative advantages. This study purposed to analyze the relationship between the concentration status of hospitals and medical charge for inpatients. National Inpatient sample data provided by the Health Insurance Review and Assessment Service (HIRA) for three years, 2009 to 2011 was used to compute the three concentration indices (Information Theory Index (ITI), Internal Herfindahl Index (IHI), and number of distinct Diagnosis-Related Groups (DRGs) treated) and total medical charge per inpatient case in each year. It was also used to select the control variables such as bed size, number of doctors per 100 beds, and locations. The ordinary least square regression models were developed and tested for hospital and general hospitals separately. The results showed that the total medical charge per inpatient case was significantly differed depending on the concentration indices, and there were positive relationships in ITI and IHI. The number of distinct DRGs had different directions in regression coefficients depending on the locations and hospital types. Hospitals had larger absolute standardized regression coefficients compare to those of general hospitals. However, their effects could be varied by the hospital types, number of doctors, and locations. It seems that hospitals have more influences on medical charges by concentrating their services than general hospitals. Study results provide knowledges to hospital administrators that concentration strategy can positive influences on the performance of small size hospitals.

• Journal of the Korean Dietetic Association
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• v.24 no.2
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• pp.159-168
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• 2018

Children's exposure to various vegetables has been associated with higher preferences and intake of vegetables. Attractive names have been reported to increase children's vegetable intake in school lunches. This study hypothesized that the number of vegetables identified correctly may be used as a measure of exposure to vegetables. The survey was administered to students (n=368) at an elementary school located in Gyeonggi-do to determine the association of number of vegetables identified correctly with factors regarding vegetable intakes and effects of descriptive menu names on consumption intentions in school lunches. Students were asked to identify the correct names for nine vegetables and rate their desire to eat six vegetable dishes labeled with general names and two different descriptive names. Descriptive menu names did not consistently increase subjects' desire to eat vegetables compared to general menu labels. Children who ate two vegetable dishes and more per meal tended to identify the names of more vegetables than those who ate less, without reaching statistical significance (P=0.057). Moreover, 5th graders who answered that they ate more than two vegetable dishes each meal had significantly higher scores in identifying vegetable names than those who did rarely (P<0.05). There was no significant association between the number of correctly identified vegetable names and children's vegetable preferences and frequency of being served vegetable dishes. Mother's vegetable preference showed a significant positive association with vegetable preferences of children (r=0.147, P<0.01) and fathers (r=0.340, P<0.01) as well as the number of correctly identified vegetables by children (r=0.183, P<0.01). The results of this study cannot support the advantage of descriptive menu labels over general menu labels. However, it suggests that the number of correctly identified vegetable names could serve as a measure of children's exposure to vegetables associated with factors regarding vegetable intake.

• Annals of Surgical Treatment and Research
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• v.95 no.5
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• pp.233-239
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• 2018

Purpose: In Korea, the working-hour limitation regulation has been implemented in December 2017. We aimed to define the difference in operative experience of surgical residents before and after implementing this policy in 2 hospitals among 8 affiliated hospitals of the Catholic Medical Center where implemented the 80 working-hour limitation policy since March 2015. Methods: All the operation records were reviewed, and the number of resident-participated surgeries between March and August in 2002 and 2017 were compared. Operations performed or participated in by residents as first assistants were defined as resident participated surgery. Results: After 2 years from the initiation of the resident work-hour limitations, the number of resident participated surgery has slightly decreased in both hospitals (Yeouido St. Mary's Hospital [YSM]: 317 to 302, St. Paul Hospital [SPH]: 635 to 461). For each resident, changes were like followings: $0{\rightarrow}21$ cases for R1, $65{\rightarrow}72$ cases for R2, $83{\rightarrow}192$ cases for R3, and $169{\rightarrow}17$ cases for R4 in YSM. In SPH, number of resident participating surgery was changed like followings: $4{\rightarrow}32$ cases for R1, $222{\rightarrow}100$ cases for R2, $317{\rightarrow}300$ cases for R3, and $92{\rightarrow}29$ cases for R4. In both hospital, while, total number of resident participating oncologic surgery has been decreased, number of resident participating appendectomy has been far increased. Activity of each grade resident is different according to hospital. Conclusion: Although total number of resident participating surgery decreased, variable changes were observed in each grade of resident according to each type of surgery and different hospitals. It is believed that comparisons of experiences from more hospitals in the future would be helpful in establishing the guidelines for surgical experience requirement of residents in Korea.

• Journal of The Korean Dental Society of Anesthesiology
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• v.6 no.2 s.11
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• pp.82-88
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• 2006

Background: The number of patients with disabilities who require general anesthesia for dental treatment is increasing. Methods: We reviewed the cases of 538 patients with disabilities who underwent outpatient general anesthesia for dental treatment at the clinic for the disabled in Seoul national university dental hospital according to the types of disabilities and comprehensive treatments. Results: The patients mean age was 17.4 years and fifty-eight percent of the patients had epilepsy, autism, mental retardation and cerebral palsy. About twenty-five percent of the patients were medically compromised such as brain disease, heart disease and genetic problem. In 142 cases, more than two dentists from the clinical departments systemically co-worked to provide the patients with comprehensive treatment as accurately and quickly as possible under general anesthesia. Conclusions: The number of medically compromised patients was high and the system of comprehensive dental treatment was well run.

• Bulletin of the Korean Mathematical Society
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• v.41 no.2
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• pp.241-256
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• 2004

In this paper, we introduce and study a new class of variational inclusions, called the general variational inclusion. We prove the equivalence between the general variational inclusions, the general resolvent equations, and the fixed-point problems, using the resolvent operator technique. This equivalence is used to suggest and analyze a few iterative algorithms for solving the general variational inclusions and the general resolvent equations. Under certain conditions, the convergence analyses are also studied. The results presented in this paper generalize, improve and unify a number of recent results.

• 대한생식의학회:학술대회논문집
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• 2007.11a
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• pp.141-141
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• 2007

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.19 no.1
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• pp.11-18
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• 2012

Purpose: The aim of this study is to evaluate the efficiency of the outpatient clinics in a hospital, using DEA. Methods: Data were collected using an activity-based costing system, medical information system, and annual reports of customer satisfaction management team of a general hospital in a city. The input variables were the number of doctors, the number of nurses, and the number of staffs. The output variables were the number of treatment times, the number of outpatient clinic patients, the total profits from outpatient clinic, the patient's satisfaction score, and the number of re-visit appointments. EMS Window version 3.1 was used to measure the efficiency score and benchmarking analysis. Results: The average efficiency score of 24 outpatient clinics was about 82.01%. Thirteen outpatient clinics had 100% efficiency score among them. The lowest efficiency score was 57.56%. Conclusion: According to these results, we found that, generally, outpatient clinics were operated very efficiently. However, some outpatient clinics had low efficiency and they needed specialized outcome improvement strategies. To increase the efficiency of inefficient outpatient clinics, we will recommend using results of DEA, as a benchmark point of the most efficient outpatient clinics.