• The Journal of the Acoustical Society of Korea
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• v.25 no.6
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• pp.277-281
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• 2006

This paper presents a method for the automatic recognition of pitch accents over syllables. The method that we propose is based on the time-delay recursive neural network (TDRNN). which is a neural network classifier with two different representation of dynamic context: the delayed input nodes allow the representation of an explicit trajectory F0(t) along time. while the recursive nodes provide long-term context information that reflects the characteristics of pitch accentuation in spoken English. We apply the TDRNN to pitch accent recognition in two forms: in the normal TDRNN. all of the prosodic features (pitch. energy, duration) are used as an entire set in a single TDRNN. while in the distributed TDRNN. the network consists of several TDRNNs each taking a single prosodic feature as the input. The final output of the distributed TDRNN is weighted sum of the output of individual TDRNN. We used the Boston Radio News Corpus (BRNC) for the experiments on the speaker-independent pitch accent recognition. π 1e experimental results show that the distributed TDRNN exhibits an average recognition accuracy of 83.64% over both pitch events and non-events.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.914-922
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• 2021

Purpose To investigate the efficacy and safety of radiofrequency ablation (RFA) for papillary thyroid microcarcinoma (PTMC) after > 10 years of follow-up. Materials and Methods This study included five patients who underwent RFA to treat PTMCs (five lesions, mean diameter 0.5 cm, range 0.4-0.7 cm) between November 2006 and December 2009. The inclusion criteria were histopathologically confirmed PTMCs, a single PTMC lesion without extrathyroidal extension, no metastasis, and ineligibility or refusal to undergo surgery. RFA was performed by a single radiologist using a radiofrequency generator and an internally cooled electrode. We retrospectively analyzed the procedure-induced complications, serial changes in ablated tumors, recurrence, and local as well as lymph node metastasis based on data obtained from medical records and radiological images. Results The mean follow-up period was 130.6 months (range 121-159 months). Three patients underwent a single RFA session, and two patients underwent two RFA sessions. We observed no procedure-induced complications. Three tumors completely disappeared after ablation, and ablation of the other two tumors resulted in the formation of a small scar that showed long-term stability (mean duration 16.8 months, range 12-27 months). At the last follow-up, no patient showed recurrence or lymph node metastasis, and serum thyroglobulin levels were within normal limits in all patients. Conclusion RFA may be effective and safe to treat low-risk PTMC in patients who refuse or are ineligible for surgery.

• Journal of Cardiovascular Imaging
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• v.31 no.3
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• pp.145-149
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• 2023

BACKGROUND: ¹⁸F-sodium fluoride positron emission tomography/computed tomography (¹⁸F-NaF PET/CT) has been proven to be useful in identification of microcalcifications, which are stimulated by inflammation. Blood speckle imaging (BSI) is a new imaging technology used for tracking the flow of blood cells using transesophageal echocardiography (TEE). We evaluated the relationship between turbulent flow identified by BSI and inflammatory activity of the aortic valve (AV) as indicated by the ¹⁸F-NaF uptake index in moderate aortic stenosis (AS) patients. METHODS: This study enrolled 18 moderate AS patients diagnosed within the past 6 months. BSI within the aortic root was acquired using long-axis view TEE. The duration of laminar flow and the turbulent flow area ratio were calculated by BSI to demonstrate the degree of turbulence. The maximum and mean standardized uptake values (SUVmax, SUVmean) and the total microcalcification burden (TMB) as measured by ¹⁸F-NaF PET/CT were used to demonstrate the degree of inflammatory activity in the AV region. RESULTS: The mean SUVmean, SUVmax, and TMB were 1.90 ± 0.79, 2.60 ± 0.98, and 4.20 ± 2.18 mL, respectively. The mean laminar flow period and the turbulent area ratio were 116.1 ± 61.5 msec and 0.48 ± 0.32. The correlation between SUVmax and turbulent flow area ratio showed the most positive and statistically significant correlation, with a Pearson's correlation coefficient (R²) of 0.658 and a p-value of 0.014. CONCLUSIONS: The high degree of trans-aortic turbulence measured by BSI was correlated with severe AV inflammation.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.397-403
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• 2024

North Korea's rapidly advancing drone development and operational capabilities have become a significant threat to South Korea's security. The drone incursions by North Korea in 2014, 2017, and 2022 demonstrate the technological advancement and provocative potential of North Korean drones. This study aims to closely analyze the military threats posed by North Korean drones and seek effective countermeasures. The research examines the development level of North Korean drone technology, its military applications, the characteristics and patterns of recent drone incursions, the adequacy and limitations of South Korea's current response systems, and future countermeasures. For this purpose, domestic and international research literature and media reports were reviewed, and specific North Korean drone incursion cases were analyzed. The results indicate that North Korea's small drones possess technological features such as small size, low altitude, low-speed flight, long-duration flight, and reconnaissance equipment. These drones pose threats that can be utilized for reconnaissance, surveillance, surprise attacks, and terrorism. Additionally, South Korea's current response systems reveal limitations such as inadequate detection and identification capabilities, low interception success rates, lack of an integrated response system, and insufficient specialized personnel and equipment. Therefore, this study suggests various technical, policy, and international cooperative countermeasures, including the development of drone detection and identification technologies, the utilization of diverse drone neutralization technologies, the establishment of legal and institutional foundations, the construction of a cooperative framework among relevant agencies, and the strengthening of international cooperation. The study particularly emphasizes the importance of raising awareness of the North Korean drone threat across South Korean society and unifying national efforts to respond to these threats.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.337-343
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• 2008

This study was conducted to investigate the distribution pattern, ecological characteristics and life cycle of the Black Soldier Fly (Hermetia illucens, BSF). The BSF was widely distributed throughout Korea. The insect was mainly found in the vicinity of and in cattle sheds, manure sheds, living waste dump grounds, and food waste dump grounds. Developmental characteristics of the BSF are as follows: the egg was long oval shaped of 887 ${\mu}m$ in the major axis and 190 ${\mu}m$ in the minor axis; it weighed 24 ${\mu}g$. Female oviposited ca. 1,000 eggs on average; eggs hatched in 81 hours under laboratory condition ($27^{\circ}C$, 60% R.H.). The duration of the larval stage was approximately $15{\sim}20$ days. The size of the last instar larvae was 21 mm. The cuticle of the pupae gradually acquired red-brown color and the size of them was 19 mm. The pupal stage was shorter for females (16 days) than males (15 days). Adults were sized about $13{\sim}20$ mm long and black-colored. The life span of adult insects was $5{\sim}8$ days for the first generation (June${\sim}$July), $7{\sim}10$ days for the second generation (Aug.${\sim}$Sept.), and $13{\sim}18$ days for the third generation (Sept.${\sim}$Oct.). Mating started on the next day of emergence and actively occurred at the third day after emergence. Mating mostly occurred between 10:00 and 16:00 during which light intensity is highest. Egg-laying started on the third day and was most frequent from the fourth to the sixth day after emergence. Similar to mating time, females oviposited mostly between 10:00 and 16:00.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.171-180
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• 1992

The precise role of radiotherapy for low grade gliomas including the optimal radiation dose and timing of treatment remains unclear. The information given by a retrosepctive analysis may be useful in the design of prospective randomized studies looking at radiation dose and time of surgical and radiotherapeutic treatment. The records of 56 patients (M:F = 29:27) with histologically verified cerebral low grade gliomas (47 cases of grade 1 or 2 astrocytomas and 9 oligodendrogliomas) diagnosed between 1979 and 1989 were retrospectively reviewed. The extent of surgical tumor removal was gross total or radical subtotal in 38 patients ($68\%$) and partial or biopsy only in the remaining 18 patients ($32\%$). Postooperative radiation therapy was given to 36 patients ($64\%$) of the total 56 patients with minimum dose of 5000 cGy (range=1250 to 7220 cGy). The 5-and 10-year survival rates for the total 56 patients were $44\%$ and $32\%$ respectively with a median survival of 4.1 years. According to the histologic grade the 5- and 10-year survivals were $52\%$ and $35\%$ for the 24 patients respectively with grade I astrocytomas compared to $20\%$ and $10\%$ for the 23 patients with grade II astrocytomas. Survival of oligodendroglioma patients was greater than those with astrocytoma ($65\%$ vs $36\%$ at 5 years), and the difference was also remarkable in the long term period of follow up ($54\%$ vs $23\%$ at 10 years). Those who received high-dose radiation therapy ($\geq$5400 cGy) had significant better survival than those who received low-dose radiation (< 5400cGy) or surgery alone (p<0.05). The 5- and 10-year survival rates were, respectively $59\%$ and $46\%$ for the 23 patients receiving high-dose radiation, $36\%$ and $24\%$ for the 13 patients receiving low-dose radiation, and $35\%$ and $26\%$ for the 20 patients with surgery alone. Survival rates by the extent of surgical resection were similar at 5 years ($46\%$ vs $41\%$), but long term survival was quite different (p<0.01) between total/subtotal resection and partial resection/biopsy ($41\%$ and $12\%$, resepctively). Previously published studies have identified important prognostic factors in these tumor: age, extent of surgery, grade, performance status, and duration of symptoms. But in our cases statistical analysis revealed that grade I histology (p<0.025) and young age (p<0.001) were the most significant good prognostic variables.

• Journal of Chest Surgery
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• v.35 no.12
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• pp.854-861
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• 2002

In this study, we reviewed our early and long-term surgical results of complete atrioventricular septal defect during the last 16 years at our hospital. Materials and Methods: Between April 1986 and March 2002, 73 patients with complete atrioventricular septal defect underwent total correction without preceding palliation. Age at repair ranged from 2 to 85 (median age, 7) months, and weight ranged from 3 to 22 (median weight, 5.9)kg. Follow-up was complete with a mean duration of 69$\pm$51 months. Results: Overall operative mortality was 16.4%(12) with 3 late deaths. One, 5, and 10 year actuarial survival rates were 96.3 %, 94.2 % and 94.2 % respectively Sixteen of 61 (22.2%) operative survivors have undergone reoperation for postoperative mitral regurgitation or left ventricular outflow tract obstruction (LVOTO). Freedom from mitral reoperation at 1, 5, and 10 years were 87.8 %, 72.4 %, and 57.8 % and freedom from LVOTO at 1, 5, and 10 years were 98.2 %, 86.3 %, and 83.2 % respectively. Summary: In this study, we found that our early surgical results improved with quite an acceptable long-term outcome. Close observation of remaining mitral regurgitation was necessary, A precise evaluation of the atrioventricular valve morphology, a meticulous surgical technique, and the adequate postoperative management are mandatory for the excellent results.

• Journal of Korean Academy of Nursing
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• v.22 no.4
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• pp.636-652
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• 1992

This study identified the impact of childhood cancer on the Korean family. The purpose was to contribute knowledge for family nursing and pediatric hospice care practice with sick children and their families. This descriptive study was conducted during a 6 month period with children who were being treated for cancer at six university hospitals in Seoul. The data were gathered from members of 68 families ; 24(Group A), with a child newly diagnosed with cancer : 27(Group B), with a child under treatment and without complications, and 17 (Group C), with a child in relapse. Medical records, structured questionnaires and interviews were used for data collection. The questionnaires and interview schedules had been used previously in Martinson's research in the USA and China. The findings, conclusions, and suggestions are as follows. 1. The impact of childhood cancer on the family. Members of the family experienced fear, helplessness, guilty feelings, and anger at the time of the initial diagnosis and at relapse. Mothers complained of headache, anorexia and poor appetite, weight loss, sleep disturbance, and bad dreams. Many of the fathers either lost or changed jobs, and all working mothers stopped working. Half the parents reported changes in their marital relationships such as frequent quarrels but also stronger unity. Family members perceived cancer as the most frightening disease. Change in their world view was expressed as living on faith understanding suffering, determining to live a better life, wanting to live an upright life and valuing health as the most important. Religious activities are found most helpful through this difficult experience. Financial debt due to the treatment and care of the sick child, burdened 22 families. The above mentioned impact was most evidant in Group B(those presently undergoing treatment) and Group C(those in relapse). Findings indicate that nursing care should embrace the family of a child who is being treated for cancer. 2. Characteristics of the child with cancer The majority of the children in this sample had a diagnosis of leukemia. Their mean age was 6.8 and the ratio of boys to girls was 1.12 ; 1. The mean hospitalization frequency was 13.5 times and the mean duration of illness was 16.8 months. Most of 1.he children perceived cancer as the most frightening disease ; 32.7% of the children described their sickness as serious. Children in Group C were hospitalized more frequently, stayed in hospital for longer periods, and expressed their sickness as quite serious more often than the other two groups. These findings indicate how much comprehensive pediatric hospice nursing care services are needed along with relevant research and nursing education. 3. Characteristics of the families. The mean age of the father was 39.5 and the mother, 36,6 ; they are in their most productive life period. Mothers especially expressed feelings of financial uneasiness and powerlessness about giving up their jobs, and guilty feelings for not providing enough care and concern to other children due to taking care of the sick one. The burden of caring for the sick child can bring negative changes in family dynamics which they think provoke potential health problems in members of the family These findings suggest a need for nursing support and counselling resources. Findings also suggest the need for ethical inquiry about such questions as who should give information to the child in regard to diagnosis and prognosis, when, and how. Other suggestions included : 1) Quality health care for childhood cancer such as home care and pediatric hospice programs should be established. 2) Special and practical consideration for long-term patients should be made in the present insurance coverage. The reimbursement period for long-term patients should be lengthened. 3) Further in-depth qualitative studies are needed. 4) Education programs including guided practice experience for pediatric hospice care practitioners are needed.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.209-217
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• 2002

Purpose : Corticosteroid has been used as the mainstay therapy of childhood NS. But SIO is one of the serious complications of long-term steroid therapy, especially in growing children. Recently calcium, calcitonin, PTH, vitamin D and bisphosphonate has been used to treat or prevent SIO in adult, which is rare in children with NS. We studied the effect of $1{\alpha}-(OH)D_3$ and Pamidronate on SIO using dual energy X-ray absorptiometry (DEXA). Patients and methods : We studied thirty patients who admitted in the Dept. of Pediatrics of Kyung Hee Medical Hospital with NS. All patients was received longterm steroid therapy. There was no history of bone, liver, or endocrine disease. The samples, serum protein, albumin, BUN, creatinine, calcium, phosphorus, and BMD were obtained before and the six months after the dose of $1{\alpha}-(OH)D_3$ and Pamidronate, respectively Results : The mean age was $6.9{\pm}3.3\;and\;6.5{\pm}2.5$ years old. The mean duration of steroid therapy was $28.8{\pm}1.8\;and\;27.6{\pm}1.0$ months. The changes of serum protein, albumin, BUN, creatinine, calcium and phosphorus level between pre-treatment and post-treatment did not show statistical significance in both $1{\alpha}-(OH)D_3$ and Pamidronate treatment group. However, BMD was increased in both from $0.472{\pm}0.12\;and\;0.457{\pm}0.10\;g/cm^2\;to\;0.533{\pm}0.12$ and $0.529{\pm}0.09\;g/cm^2$ after treatment. (P<0.05) Conclusion : Both $1{\alpha}-(OH)D_3$ and Pamidronate appears to be effective in treating and preventing SIO in children with nephrotic syndrome requiring long-term steroid therapy.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.350-355
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• 2002

Background: Most of pulmonary regurgitation with or without stenosis appears to be well tolerated early after the repair of pulmonary outflow tract. However, it may result in symptomatic right ventricular dilatation, dysfunction and arrhythmias over a long period of time. We studied the early outcome of pulmonary valve replacement with tissue valves for patients with the above clinical features. Material and Method: Sixteen consecutive patients who underwent pulmonary valve replacement from September 1999 to February 2002 were reviewed(9 males and 7 females). The initial diagnoses included tetralogy of Fallot(n=11), and other congenital heart anomalies with pulmonary outflow obstruction(n=5). Carpentier-Edwards PERIMOUNT Pericardial Bioprostheses and Hancock porcine valves were used. The posterior two thirds of the bioprosthetic rim was placed on the native pulmonary valve annulus and the anterior one third was covered with a bovine pericardial patch. Preoperative pulmonary regurgitation was greater than moderate degree in 13 patients. Three patients had severe pulmonary stenosis. Tricuspid regurgitation was present in 12 patients. Result: Follow-up was complete with a mean duration of 15.8 $\pm$ 8.5months. There was no operative mortality. Cardiothoracic ratio was decreased from 66.0 $\pm$ 6.5% to 57.6 $\pm$ 4.5%(n=16, p=0.001). All patients remained in NYHA class I at the most recent follow-up (n=16, p=0.016). Pulmonary regurgitation was mild or absent in all patients. Tricuspid regurgitation was less than trivial in all patients. Conclusion: In this study we demonstrated that early pulmonary valve replacement for the residual pulmonary regurgitation with or without right ventricular dysfunction was a reasonal option. This technique led to reduce the heart size, decrease pulmonary regurgitation and tricuspid regurgitation as well as to improve the patients'functional status. However, a long term outcome should be cautiously investigated.