(A) study on the information content of cash dividend changes related to future earnings Changes

학위논문(석사) - 한국과학기술원 : 금융공학프로그램, 2021.8,[iii, 47 p. :]본 논문은 기업의 배당과 관련하여 현금배당 변동이 미래이익 변화에 대한 정보를 제공하는지에 대하여 실증적으로 분석하였다. 2009년부터 2018년까지 국내 상장기업 현금배당 건을 대상으로 분석한 결과 배당 변동의 방향에 따라 배당의 정보효과가 다르게 나타나고 있음을 발견하였다. 배당이 증가한 경우 배당의 정보효과가 나타나지 않은 반면, 배당이 감소한 경우에는 배당변동률과 미래이익 변화율 사이에 통계적으로 유의한 상관관계가 존재하여 배당 감소폭이 클수록 미래이익의 감소도 크게 나타났다. 또한, 배당 감소의 정보효과가 2년간 지속됨을 확인하였으며, 이는 배당이 감소한 기업의 경우 향후 2년 동안의 이익수준이 배당 감소가 발생한 기준년도의 이익수준에 미치지 못할 가능성이 있음을 의미한다.한국과학기술원 :금융공학프로그램

교모세포종의 병변 부위별 단백질 발현 양상에 대한 연구

Thesis(doctors) --서울대학교 대학원 :의학과(신경외과학 전공),2009.2.Docto

대뇌 피질이형성증에 의한 소아기 간질의 외과적 치료성적과 예후인자

학위논문(석사)--서울대학교 대학원 :의학과 신경외과학전공,2001.Maste

大規模 規則形 시스템에 대한 選別的 推論

학위논문(석사) - 한국과학기술원 : 경영과학과, 1987.2, [ [iii], 42, [1] p. ]In the large scale rule-based systems, the search efficiency for inference becomes more crucial as the number of rules increases. This thesis therefore proposes a method of selective inference, named sub-graph inference, to enhance the search efficiency under the backward chaining inference environment. The key concept of sub-graph inference is that only the relevant rules for a certain goal are invoked during the inference so that the large number of irrelevant rules would not deteriorate the search efficiency. However, to make the sub-graph inference possible, the goal structure consistent with knowledge base should beforehand be organized. This thesis therefore has developed a mechanism to automate this goal structuring process. A prototype named SUGAR(Sub-Graph Automatic Reasoner) is developed on the microcomputer to illustrate our approach.한국과학기술원 : 경영과학과

Prevalence and clinical characteristics of intervertebral disc herniation in adolescence: a study based on examinations for conscription

Objective: The authors analyzed the large series of intervertebral disc herniation in adolescence to evaluate the prevalence, clinical characteristics, and possible risk factors on the basis of the data from the examinations for conscription. Materal and methods: Of 77685 nineteen-old-males who were given an examination for conscription at Regional Military Manpower Administration of Seoul in 2002, 382 patients exempted from conscription due to intervertebral disc herniation were analyzed. The diagnosis were made from the medical certificate, medical record, magnetic resonance imaging(MRI)(or computed tomography(CT)) which examinee presented and confirmed with the aid of reexamination of CT. Radiological characteristics and severity of intervertebral disc herniation as well as structural abnormalities of vertebral columns were carefully evaluated with CT scan and MRI scan. Possible risk factors like overweight, structural abnormality of vertebral column, trauma were analyzed statistically using one-sample T-test and chi-square test on the assumption that P value less than 0.05 was considered statistically significant. Result: Prevalence of intervertebral disc herniation in adolescence aged nineteen years and younger were 0.5%. L4-5 level was the most frequently affected site followed by L5-Sl. Of all 382 patients of intervertebral disc herniation, 29% were considered serious with reference to radiological evidence of root compression or significant discogenic spinal stenosis. Limbus fracture was found in 6.8% of patients. Overweight was the significant risk factor of the disease(p=0.0). However, neither structural abnormality of vertebral column nor trauma showed any relation to pathogenesis of intervertebral disc herniation. Conclusion: In adolescence aged nineteen years and younger, the prevalence of intervertebral disc herniation was 0.5% and accompanying limbus fracture was more frequent when compared with adult. Overweight was the only significant risk factor of the disease

Treatment Outcome and Prognostic Factors of Cushing's Disease in Adults

Objectives：The authors analyzed the surgical series of Cushings disease to evaluate the proper treatment policy and to verify the possible prognostic factors. Material and Methods：Of 50 patients diagnosed as Cushings disease and operated at Department of Neurosurgery of our institute between 1988 and 1999, 48 patients with available medical records were analyzed retrospectively. Mean follow-up period was 48 months(3 to 109 months). Preoperative diagnosis was made after evaluating the patients with multiple-stage endocrinological studies and 31 selective patients were evaluated with inferior petrosal sinus sampling(IPSS). Magnetic resonance imaging(MRI) and/or high resolution computerized tomography(CT) was done in all patients. A total of 51 transsphenoidal adenomectomy(TSA) were performed including 3 revision for initial surgical failure cases. Remission was decided on the basis of both endocrinological criteria and clinical status. Radiation and/or ketoconazole therapy were applied to failed cases. For the verification of prognostic factors, the authors evaluated the statistical significance of multiple variables over remission rate by chi-square test. Result：Sensitivity of IPSS for central localization was 93.5% which was better than that of MRI(87.5%). But for lateralization, it was 72.4% for IPSS versus MRI 90.5%. Success rate of TSA was 82%(42/51) and recurrence rate was 9%(4/48). When including adjuvant treatments for surgically failed cases, overall success rate was 89.6% and all of 3 reoperated cases(TSA) due to recurrence were successful. Significant complication occurred in 7.8%(4/51) after TSA including hypopituitarism, diabetes insipidus, and visual loss. Non-existence of tumor in MRI and prolonged symptom duration(>3 years) were significant prognostic factors. Conclusion：TSA can be considered as initial treatment for Cushings disease. In surgically failed cases, multiple treatment modality may improve the overall outcome and repeated TSA for recurrent cases seem to provide similar success.본 논문은 서울대병원 임상 연구비의 일부 지원으로 이루어졌음

The Korean Society for Neuro-Oncology (KSNO) Guideline for Antiepileptic Drug Usage of Brain Tumor: Version 2021.1

Background: To date, there has been no practical guidelines for the prescription of antiepileptic drugs (AEDs) in brain tumor patients in Korea. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for AED usage in brain tumors since 2019. Methods: The Working Group was composed of 27 multidisciplinary medical experts in Korea. References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of the keywords. Results: The core contents are as follows. Prophylactic AED administration is not recommended in newly diagnosed brain tumor patients without previous seizure history. When AEDs are administered during peri/postoperative period, it may be tapered off according to the following recommendations. In seizure-naive patients with no postoperative seizure, it is recommended to stop or reduce AED 1 week after surgery. In seizure-naive patients with one early postoperative seizure (<1 week after surgery), it is advisable to maintain AED for at least 3 months before tapering. In seizure-naive patients with ≥2 postoperative seizures or in patients with preoperative seizure history, it is recommended to maintain AEDs for more than 1 year. The possibility of drug interactions should be considered when selecting AEDs in brain tumor patients. Driving can be allowed in brain tumor patients when proven to be seizure-free for more than 1 year. Conclusion: The KSNO suggests prescribing AEDs in patients with brain tumor based on the current guideline. This guideline will contribute to spreading evidence-based prescription of AEDs in brain tumor patients in Korea. Keywords: Antiepileptic drug; Brain tumors; Guideline; Korean Society for Neuro-Oncology; Practice