• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.3
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• pp.37-50
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• 2013

The purpose of this study is to determine the indicators and the criteria to classify types of train delays of high-speed rail in South Korea. Types of train delays have divided into the chronic delays and the knock-on delays. The Indicators based on relevance, reliability, and comparability were selected with arrival delay rate of over five minutes, median of arrival delays of preceding train and following train, knock-on delay rate of over five minutes, correlation of delay between preceding train and following train on intermediate and last stations, average train headway, average number of passengers per train, and average seat usages. Types of train delays were separated using the Ward's hierarchical cluster analysis. The criteria for classification of train delay were presented by the Fisher's linear discriminant. The analysis on the situational characteristics of train delays is as follows. If the train headway in last station is short, the probability of chronic delay is high. If the planned running times of train is short, the seriousness of chronic delay is high. The important causes of train delays are short headway of train, shortly planned running times, delays of preceding train, and the excessive number of passengers per train.

• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.8-16
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• 2008

The aim of this study was to evaluate the motor recovery in 4 chronic hemiparetic patients with Fugl-Meyer (FM) and EMG characteristics before and after the training program. The training was performed at 1hr/day, 5days/week during 6 weeks in 4 chronic stroke patients. Electromyographic activities of the affected hand were recorded during isometric wrist flexion/ extension movements. In all patients, FM was significantly improved after the 6-week training. Onset/offset delay of muscle contraction significantly decreased in the affected wrist after the training. The co-contraction ratio of flexor/extensor muscles decreased significantly. Also, onset/offset delay of muscle contraction and co-contraction ratio correlates significantly with upper limb motor impairment and motor recovery. This EMG technique allows an objective evaluation of changes in muscle activity in post-stroke patients, providing easily measurable, quantitative indices of muscle characteristics.

• Korean Journal of Applied Biomechanics
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• v.33 no.4
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• pp.155-163
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• 2023

Objective: The purpose of this study is to identify the difference in the quality of muscle contraction and kick movements according to the presence or absence of back pain in body kick movements of mixed martial arts athletes. Method: In this study, four athletes (32.75 ± 4.79 yrs, 172.50 ± 5.20 cm, 77.73 ± 13.28 kg) who have suffered chronic back pain for more than three months and scored 12 points in the Korean version of ODI. Four painless athletes (33.50 ± 4.04 yrs, 174.25 ± 3.10 cm, 83.50 ± 10.21 kg) participated. Results: During the body kick operation, the pain group had significantly higher muscle activity in the right Transversus abdominis and right Rectus femoris compared to the normal group (p<.05). In the rectus abdominis, the muscle activity was significantly lower than that of the normal group (p<.05). Also, the pain group has a higher toe speed than the normal group Significantly slow (p<.05), there was a delay in contraction of the Transversus abdominis. Conclusion: The results of this study suggest that chronic pain in the lumbar spine degrades the core's function, resulting in inefficient coordination such as Transversus abdominis contraction delay and Transversus abdominis and Rectus femoris excessive activation to compensate for it.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.246-249
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• 2004

The purpose of this study was to investigate the characteristics between EMG timing of muscle contraction and motor impairment in chronic hemiplegic stroke patients. Delay time and co-contraction of 4 patients who had stroke less than 3 years were measured during isometric wrist flexion and extension along the 3 seconds beep signal. Onset and offset of muscle contraction were significantly delayed on the more affected sides than control sides. Offset was significantly delayed than the onset on the affected sides in wrist flexion. Also, recruitment of antagonist was larger than agonist on the affected sides. Co-contraction ratio on the affected side was significantly smaller than control sides in wrist flexion. In affected sides, Fugl-Meyer motor assessment(FMA) shows the correlation of onset delay in wrist flexion and extension. However, co-contraction ratio correlated with FMA in wrist flexion. EMG assessment is likely to be useful outcome measure and provide insights into mechanism for motor recovery in stroke patients.

• Journal of Korean Foot and Ankle Society
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• v.20 no.4
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• pp.182-186
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• 2016

The tibialis anterior tendon functions as a major dorsiflexor of the ankle. A rupture in this tendon can cause serious problems in the ambulatory function. A closed traumatic rupture without open wound or an atraumatic rupture can delay diagnosis and treatment. There are not enough guidelines for an effective surgical treatment on this chronic condition. Herein, we report two cases of chronic tibialis anterior disruption successfully treated by semitendinosus autograft.

• Childhood Kidney Diseases
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• v.25 no.1
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• pp.1-7
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• 2021

Chronic kidney disease (CKD) in children is associated with various complications, including poor growth and development, mineral bone disorder, cardiovascular disease, kidney failure, and mortality. Slowing down the progression of CKD is important since CKD is often not curable. Prospective cohort studies have been conducted to understand the progression and outcomes of CKD in children, and these studies have identified non-modifiable and modifiable risk factors. Recognition of known risk factors and early intervention are important to delay the progression of kidney function decline in children.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.12 no.2
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• pp.85-93
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• 2012

Purpose: Developmental delay is caused by very diverse etiologic diseases. Most chronic disorders has some influence on development. Chronic or acute disorders of CNS are main etiologic diseases of developmental delay. Up to now, over 60 diseases are included in organic acidopathies and most of them causes acute or chronic recurrent CNS damage and developmental delay. We have done this study to find out the importance of organic acidopathies causing developmental delay in Korean childhood and adolescent patients. Method: Retrograde analysis for 738 patients with developmental delay whose clinical informations are available and have done urine organic acid analysis for 5 years period, between Jan. 1st 2007 to Dec. 31th 2011. Statistical analysis was done with Student's t test using SPSS. Result: Out of 738 patients, 340 patients (46.1%) showed abnormalities on urine organic acid analysis. The most frequent disease was mitochondrial respiratory chain disorders (MRCD) (253, 34.3%), followed by ketolytic defects(39, 5.3%), 3-hydroxyisobutyric aciduria (26, 3.5%), glutaric aciduria type II (8, 1.1%), pyruvate dehydrogenase deficiency (3, 0.4%), 3-methylglutaric aciduria (2, 0.3%), glutaric aciduria type I (2, 0.3%), ethylmalonic aciduria (1, 0.15%), methylmalonic aciduria (1, 0.15%), HMG-CoA lyase deficiency (1, 0.15%), 3-methylcrotonylglycinuria (1, 0.15%), fatty acid oxidation disorders(1, 0.15%) and FAOD (1, 0.15%). Conclusion: Mitochondrial disorders are most frequent etiologic disease on all age group, followed by ketolytic defects and various organic acidopathies. The number and diversities of organic acidopathies emphasize meticulous evaluation of basic routine laboratory examinations and organic acid analysis with initial sample on every developmental patient.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.16 no.2
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• pp.131-134
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• 2013

Cecal volvulus is uncommon in pediatric patients and there are few reports of cecal volvulus with cerebral palsy. Here, we report the case of a 19-year-old male patient who presented with abdominal distension, a history of cerebral palsy, refractory epilepsy due to lissencephaly, and chronic constipation. An abdominal x-ray and computed tomography without contrast enhancement showed fixed dilated bowel intensity in the right lower abdomen. Despite decompression with gastric and rectal tube insertion, symptoms did not improve. The patient underwent an exploratory laparotomy that revealed cecal volvulus. Cecal volvulus usually occurs following intestinal malrotation or previous surgery. In this patient, however, intestinal distension accompanying mental disability and chronic constipation resulted in the development of cecal volvulus. We suggest that cecal and proximal large bowel volvulus should be considered in patients presenting with progressive abdominal distension combined with a history of neuro-developmental delay and constipation.

• Archives of Obesity and Metabolism
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• v.1 no.2
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• pp.66-73
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• 2022

Obesity is an increasing public health and medical issue worldwide. It has been associated with several comorbidities, including diabetes, cardiovascular disease, stroke, and cancer. Chronic kidney disease (CKD) is another important comorbidity of obesity. Other major causes of CKD include hypertension and diabetes. However, the association between obesity and CKD is often overlooked. Among patients with CKD, patients with obesity were more vulnerable to have rapid kidney function decline than that of those with normal weight. Additionally, CKD is more prevalent among patients with obesity. These aggravations are induced through multiple mechanisms, specifically metabolic impairment of obesity and mechanical burden because of increasing intraabdominal renal pressure. Furthermore, the inflammation and lipotoxicity, caused by obesity, are critical in the CKD aggravation in patients with obesity. To prevent this, all adult patients with obesity are tested for CKD. The workup includes the estimated glomerular filtration rate and regular follow-up. Step-wise management is required for patients with obesity with CKD. Prompt reduction and management of obesity effectively delay CKD progression among patients with obesity and CKD. Therefore, weight loss is a core management for patients with obesity and CKD. Based on several studies, this article focused on the association between CKD and obesity, as well as the diagnosis and weight management of patients with obesity and CKD.

• Childhood Kidney Diseases
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• v.28 no.2
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• pp.51-58
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• 2024

Patients with chronic kidney disease (CKD) bear a significant financial burden and face numerous complications and higher mortality rates. The progression of CKD is associated with glomerular injury caused by glomerular hyperfiltration and oxidative stress. Factors such as uncontrolled hypertension, elevated urine protein levels, anemia, and underlying glomerular disease, contribute to CKD progression. In addition to conservative treatment, several medications are available to combat the progression of CKD to end-stage kidney disease. Renin-angiotensin-aldosterone system blockers could slow the progression of CKD by reducing glomerular hyperfiltration, lowering blood pressure, and decreasing inflammation. Mineralocorticoid receptor antagonists inhibit the mineralocorticoid receptor signaling pathway, thereby attenuating inflammation and fibrosis. Sodium-glucose cotransporter 2 inhibitors exhibit protective effects on the kidneys and against cardiovascular events. Tolvaptan, a selective vasopressin V2-receptor antagonist, decelerates the rate of increase in total kidney volume and deterioration of kidney function in patients with rapidly progressive autosomal dominant polycystic kidney disease. The protective effects of AST-120 remain controversial. Due to a lack of evidence regarding the efficacy and safety of these medications in children, it is imperative to weigh the benefits and adverse effects carefully. Further research is essential to establish the efficacy and safety profiles in pediatric populations.