• Communications of the Korean Mathematical Society
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• v.13 no.3
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• pp.465-473
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• 1998

A real m $\times$ n matrix A is semipositive (SP) if there is a vector x $\geq$ 0 such that Ax > 0, inequalities being entrywise. A is minimally semipositive (MSP) if A is semipositive and no column deleted submatrix of A is semipositive. We give a necessary and sufficient condition for the sign pattern matrix with n positive entries to be minimally semipositive.

• Journal of Korean Neurosurgical Society
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• v.56 no.4
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• pp.303-309
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• 2014

Objective : The purpose of this study was to retrospectively review cases of intracerebral hemorrhage (ICH) medically treated at our institution to determine if the CT angiography (CTA) 'spot sign' predicts in-hospital mortality and clinical outcome at 3 months in patients with spontaneous ICH. Methods : We conducted a retrospective review of all consecutive patients who were admitted to the department of neurosurgery. Clinical data of patients with ICH were collected by 2 neurosurgeons blinded to the radiological data and at the 90-day follow-up. Results : Multivariate logistic regression analysis identified predictors of poor outcome; we found that hematoma location, spot sign, and intraventricular hemorrhage were independent predictors of poor outcome. In-hospital mortality was 57.4% (35 of 61) in the CTA spot-sign positive group versus 7.9% (10 of 126) in the CTA spot-sign negative group. In multivariate logistic analysis, we found that presence of spot sign and presence of volume expansion were independent predictors for the in-hospital mortality of ICH. Conclusion : The spot sign is a strong independent predictor of hematoma expansion, mortality, and poor clinical outcome in primary ICH. In this study, we emphasized the importance of hematoma expansion as a therapeutic target in both clinical practice and research.

• Journal of applied mathematics & informatics
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• v.35 no.5_6
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• pp.551-563
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• 2017

In this paper, by using fixed point theorems in cones, the existence of positive solutions is considered for nonlinear m-point boundary value problem for the following second-order dynamic equations on time scales $$u^{{\Delta}{\nabla}}(t)+a(t)f(t,u(t))=0,\;t{\in}(0,T),\;{\beta}u(0)-{\gamma}u^{\Delta}(0)=0,\;u(T)={\sum_{i=1}^{m-2}}\;a_iu({\xi}_i),\;m{\geq}3$$, where $a(t){\in}C_{ld}((0,T),\;[0,+{\infty}))$, $f{\in}C([0,T]{\times}[0,+{\infty}),\;(-{\infty},+{\infty}))$, the nonlinear term f is allowed to change sign. We obtain several existence theorems of positive solutions for the above boundary value problems. In particular, our criteria generalize and improve some known results [15] and the obtained conditions are different from related literature [14]. As an application, an example to demonstrate our results is given.

• Journal of applied mathematics & informatics
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• v.28 no.5_6
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• pp.1171-1184
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• 2010

In this paper, by using fixed point theorems in cones, the existence of positive solutions is considered for nonlinear m-point boundary value problem for the following second-order dynamic equations on time scales $({\phi}(u^{\Delta}))^{\nabla}+a(t)f(t,\;u(t))=0$, t $\in$ (0, T), $u(0)=\sum\limits^{m-2}_{i=1}a_iu(\xi_i)$, $\phi(u^{\Delta}(T))=\sum\limits^{m-2}_{i=1}b_i{\phi}(u^{\Delta}(\xi_i))$, where $\phi$ : R $\rightarrow$ R is an increasing homeomorphism and positive homomorphism and ${\phi}(0)=0$. In [27], we obtained the existence results of the above problem for an increasing homeomorphism and positive homomorphism with sign changing nonlinearity. The purpose of this paper is to supplement with a result in the case when the nonlinear term f is nonnegative, and the most point we must point out for readers is that there is only the p-Laplacian case for increasing homeomorphism and positive homomorphism due to the sign restriction. As an application, one example to demonstrate our results are given.

• The Korean Journal of Nuclear Medicine
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• v.23 no.1
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• pp.35-39
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• 1989

The "rim sign" is a rim of increased hepatic activity adjacent to the gall bladder fossa and known as an useful indicator of acute cholecystitis. Also, many reports suggested that if rim sign is positive there is an increased risk for complications such as perforation and gangrene. To evaluate the usefulness of this rim sign, we reviewed 32 cases that were pathologically confirmed. The incidence of rim sign was 47% similar to other reports but with our results, the rim sign was not specific to acute cholecystitis nor indicator of increased risk for complications.

• The Research Journal of the Costume Culture
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• v.10 no.3
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• pp.213-235
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• 2002

The purpose of this study was to recognize the meanings of plastic language by analyzing the sign of the Graffiti depicted in western modern costumes. And the scope of this study was focused on analysing the costumes from 1980's when the Graffiti was recognized as one of the plastic arts. Graffiti was an unprofessional and covert desire of self-expression, having a close relation with our lives. It was used in diverse ways with repeating creation, development, and extinction, from expressing liveliness in Old Stone Age through describing symbolic meaning in the modern art. Graffiti means rude, humorous, or political writing and pictures on the walls of buildings. It's different from the delicate letters or pictures to inscript on the tree or rocks. Being introduced as part of Post-modernism in the 1970s, Graffiti was acknowledged as a new artistic action with the culture of hip-hop. In addition the Graffiti, the expression of sign was reflected artist's internal consciousness with boundless sign. The sign is something to transmit message from the nonverbal point of view, the oldest sign was the sign for petition or the expression of something as a primitive form. Sign can be defined as a framework of life inherited as a practice from the primitive age long past. Graffiti was cited as a concrete example of sign, theme of this paper, and general understanding on sign expression was pursued through free work which all artists present with essential and positive ways using signs, their own languages, and life style. The result of this study was summarized as follows: Since the end of the 20th century, a lot of fashion designers have represented symbolic images, such as letter and signs, as purely personal ways of expression through the western costumes. It was found that fashion designers of the Graffiti whose free work style from inherent inner consciousness might provide a basic framework to search for complex signs of modem costumes naturally understood life itself as plastic art, and sublimated human inherent desire and their inner world through their works.

• Journal of Preventive Medicine and Public Health
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• v.25 no.1 s.37
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• pp.26-33
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• 1992

The carpal tunnel syndrome is one of the most common peripheral nerve entrapment syndromes. The typical symptoms are pain, numbness and paresthesia in the median nerve territory of the hand. Recently, it is widely recognized that occupational factor is regarded as the important cause of the carpal tunnel syndrome. Clinical study is performed in the 42 female workers who is repetitively working at packing department in a rayon manufacturing factory from November 1991 till March 1992. The study included a questionnaire, physical examinations, and the neurophysiological test. The summary of the results obtained was as follows : 1. Among 42 packing workers, 9 workers(21.4%) were diagnosed as carpal tunnel syndrome by electromyography. The affected side was bilateral in 4 workers(9.5%), right in 4 workers(9.5%), and left in one worker(2.4%). 2. Among 42 subjects, 28 workers(66.7%) complained the clinical symptoms related to carpal tunnel syndrome, 11 workers(26.2%) showed positive Phalen sign, and 7 workers(16.7%) showed positive Tinel sign. 3. Researchers regard electromyographic finding as the gold standard for diagnosis of carpal tunnel syndrome. The sensitivity and specificity of the clinical symptoms to diagnose the carpal tunnel syndrome were 0.89, 0.39 respectively. If the carpal tunnel syndrome is diagnosed by the combination of the positive findings of the symptoms and the physical examinations, either Tinel or Phalen sign, the sensitivity and specificity were 0.67 and 0.76 respectively. Considering above results, though this small number of workers is not adequate for epidemiologic conclusions, carpal tunnel syndrome seems to be an important occupational disorder among packing workers in a rayon manufacturing factory.

• Investigative Magnetic Resonance Imaging
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• v.22 no.2
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• pp.94-101
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• 2018

Purpose: To determine the value of the appearance of the high signal intensity halo sign for detecting carotid intraplaque hemorrhage (IPH) on maximum intensity projection (MIP) of time-of-flight (TOF) MR angiography (MRA), based on high signal intensity on magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) sequencing. Materials and Methods: A total of 78 carotid arteries in 65 patients with magnetization-prepared rapid acquisition gradient-echo (MPRAGE) positive on carotid plaque MR imaging were included in this study. High-resolution MR imaging was performed on a 3.0-T scanner prior to carotid endarterectomy or carotid artery stenting. Fast spin-echo T1- and T2-weighted axial imaging, TOF, and MPRAGE sequences were obtained. Carotid plaques with high signal intensity on MPRAGE > 200% that of adjacent muscle on at least two consecutive slices were defined as showing IPH. Halo sign of high signal intensity around the carotid artery was found on MIP from TOF MRA. Continuous and categorical variables were compared among groups using the Mann-Whitney test and Fisher's exact tests. Results: Of these 78 carotid arteries, 53 appeared as a halo sign on the TOF MRA. The total IPH volume of patients with a positive halo sign was significantly higher than that of patients without a halo sign ($75.0{\pm}86.8$ vs. $16.3{\pm}18.2$, P = 0.001). The maximum IPH axial wall area in patients with a positive halo sign was significantly higher than that of patients without a halo sign ($11.3{\pm}9.9$ vs. $3.7{\pm}3.6$, P = 0.000). Conclusion: High signal intensity halo of IPH on MIP of TOF MRA is associated with total volume and maximal axial wall area of IPH.

• Journal of Korean Neurosurgical Society
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• v.58 no.4
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• pp.309-315
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• 2015

Objective : An advantage of surgical treatment over conservative treatment of spontaneous intracerebral hemorrhage (ICH) is controversial. Recent reports suggest that contrast extravasations on CT angiography (CTA) might serve as a crucial predictor of hematoma expansion and mortality. The purpose of this study was aimed at investigating the efficacy of surgical treatment in patients with spot sign positive ICH. Methods : We used our institutional medical data search system to identify all adult patients who admitted for treatment of ICH between January 1, 2007 and January 31, 2012. Patients were classified two groups into a surgical group (n=27) and a conservative treatment group (n=28). Admission criteria were the following: age 20-79 years, spontaneous supratentorial ICH, Glasgow Coma Score Ranging from 9 to 14, ICH volume ${\geq}20mL$, and treatment within 24 hours. Results : Fifty-five patients were analyzed. There was no significant difference in the ICU stay between the conservative treatment group ($7.36{\pm}3.66days$) and the surgical treatment group ($6.93{\pm}2.20days$; p=0.950). There was a significant difference in the in-hospital stay between the conservative treatment group ($13.93{\pm}8.87days$) and the surgical treatment group ($20.33{\pm}6.37days$; p=0.001). Overall mortality at day 90 after ICH was 36.4%; this included 16 of 28 patients (57.1%) in the conservative group and 4 of 27 patients (14.8%) in the surgical group. In univariate analysis, there was a positive effect of the surgical treatment in reducing mortality at 90 days (p=0.002), Glasgow Outcome Scale (GOS) at 90-day (p=0.006), and modified Rankin Scale (mRS) at 90-day (p=0.023). In multivariate logistic analysis, there was a significant difference in mortality (odds ratio, 0.211; 95% confidence interval, 0.049-0.906; p=0.036) between the groups at 90-day follow-up. However, there was no significant difference in GOS (odds ratio, 0.371; 95% confidence interval, 0.031-4.446; p=0.434) and mRS (odds ratio, 1.041; 95% confidence interval, 0.086-12.637; p=0.975) between the groups at 90-day follow-up. Conclusion : In this study of surgical treatment of supratentorial ICH in patients with spot sign positive in CTA was associated with less mortality despite of long duration of in-hospital stay. We failed to show that clinical outcome benefit of surgical treatment compared with conservative treatment in patients with spot sign positive ICH.

• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.517-529
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• 2012

In this paper, the existence theorem of two positive solutions is established for nonlinear m-point boundary value problem by using an inequality for the following third-order differential equations $$({\phi}(u^{\prime\prime}))^{\prime}+a(t)f(t,u(t))=0,\;t{\in}(0,1)$$, $${\phi}(u^{\prime\prime}(0))=\sum^{m-2}_{i=1}a_i{\phi}(u^{\prime\prime}({\xi}_i)),\;u^{\prime}(1)=0,\;u(0)=\sum^{m-2}_{i=1}b_iu({\xi}_i)$$, where ${\phi}:R{\rightarrow}R$ is an increasing homeomorphism and homomorphism and $\phi(0)=0$. The nonlinear term f may change sign, as an application, an example to demonstrate our results is given.