• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.1-10
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• 1990

This paper represents the hull form development of a high speed container ship based on the thin ship theory, Hess & Smith method, the reference ship data and model test results. The high efficiency propeller designed by the lifting surface theory shows good performance in the cavitation and the pressure fluctuation force. Also, the optimum design technique based on the finite element method was adopted for the hull structure design and the hull vibration analysis. Finally, the performance of a newly developed container ship has been compared with the sea trial results and the excellent performance in speed, vibration, etc. was confirmed.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.118-118
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• 2001

To find out localization of mercury in male reproductive system, adult male mice were injected subcutaneously with methyl mercuric chloride (1mg/mouse) once per week for 20, 40 and 70 days. The experimental periods later, animals were sacrificed by transcardial perfusion and organs were removed, dehydrated, and embedded in paraffin.(omitted)

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.139-144
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• 1999

이땅에 근대화, 산업화가 시작되면서 전력수요량은 계속 증가 일로를 건고 있다. 최근에 IMF의 영향으로 전력수요의 증가세가 주춤한 것은 사실이나 점차 회복기에 들고 있는 우리 경제 사정을 감안할 때 그 수요가 계속 증가할 것임은 명약관화하다. 또한 전력 수요의 분포가 겨울보다는 여름에, 야간보다는 주간에 집중하는 전력수요의 편중현상도 뚜렷해지고 있다.(중략)

• Journal of the Society of Naval Architects of Korea
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• v.35 no.2
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• pp.8-19
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• 1998

Nonlinear flow characteristics of a hydrofoil running under the free surface are investigated based on potential flow theory using singularity distribution techniques. Following Hess & Smith's method[12], sources and vortices are distributed on the surface of the foil and Rankine sources are distributed at a distance above the undisturbed free surface to solve the nonlinear free surface waves(so called Raised Panel Method). Using the linearized Neumann-Kelvin solution, the conversed solutions which rigidly satisfy the nonlinear free surface condition is obtained through an iterative technique. It is validated that the nonlinear solutions are compared with Duncan's experimental results(NACA 0012, $\alpha=5^{\circ}$), showing good correlations with each other. At a very shallow submergence and a very high speed the converged solutions are obtained. As the speed increases higher, it is shown that the difference between the nonlinear and linear solutions are trivial. Finally, the effects of the camber and thickness on the nonlinear flow characteristics of the foil are investigated.

• Journal of Korean Neurosurgical Society
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• v.41 no.3
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• pp.153-156
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• 2007

Objective : Cerebral vasospasm is a devastating medical complication of aneurysmal subarachnoid hemorrhage [SAH]. Therefore, prompt detection of vasospasms in aneurysmal SAH is important to the clinical outcome of the patient. For better prediction and effective management of vasospasms, identifying risk factors is essential. This study is aimed at evaluating the relationship between clinical hematologic values, especially white blood cell count, and cerebral vasospasms. Methods : A retrospective review was conducted on 249 patients with aneurysmal SAH who underwent surgical clipping [230 cases] or endovascular intervention [19 cases] between 2003 and 2005. The underlying clinical conditions assessed were leukocytosis, fever, hypertension, diabetes, smoking, Hunt and Hess grade, Fisher grade, aneurysm location, and direct clipping versus endovascular intervention. Results : Two hundred forty-nine patients were treated for aneurysmal SAH during this period. We selected 158 patients in Hunt and Hess grade I - III. Cases of infectious conditions, rebleeding and other surgical/clinical complications were excluded. Vasospasms occurred $7.0{\pm}3.1$ days after the onset of SAH. There were several independent predictors of vasospasm : Fisher grade III [p=0.002], fever within two weeks on admission [p<0.001], and a serum leukocyte count >$10.8{\times}10^3/mm^3$ on admission [p=0.018]. Conclusion : This study results indicate that leukocytosis and fever increase the risk of vasospasms. However, other known risk factors, such as hypertension and smoking, were not correlated with respect to predicting of cerebral vasospasm. Monitoring the serum leukocyte count may be a helpful and useful marker of vasospasms after aneurysmal SAH.

• Journal of Korean Neurosurgical Society
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• v.40 no.5
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• pp.357-362
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• 2006

Objective : The incidence of aneurysmal subarachnoid hemorrhage has been increasing. At the same time, surgical results for elderly patients are unsatisfactory and no guidelines of treatment are available. We carried out a study comparing variable factors and surgical results between young and old age groups to find ways to improve prognosis. Methods : A retrospective study was carried out on 754 patients who were operated on between 1990 and 2004 by the same surgeon in our hospital. The patients were divided into seven groups according to age : 93 patients below 40 years of age [Group I], 419 patients aged $40{\sim}59$ [Group II], 115 patients aged $60{\sim}64$ [Group III], 82 patients aged $65{\sim}69$ [Group IV], 28 patients aged $70{\sim}74$ [Group V], 12 patients aged $75{\sim}79$ [Group VI] and 5 patients over the age of 80 [Group VII]. We then checked their medical history, Fisher's grade, Hunt-Hess grade, postoperative complications, and Glasgow Outcome Scale. Results : Age was not a statistically significant factor among patients below 70 years of age [P $value{\ge}0.05$]. But for those aged 70 and older, the age factor had a statistical value [P $value{\le}0.001$]. In addition, there was a close correlation between Hunt-Hess grade IV and V patients, and those with vasospasm, and hydrocephalus after surgery, with poor prognosis in elderly patients as well as young patients [P $value{\le}0.001$]. Conclusion : Advanced age [under the age of 70] dose not precluded adequate surgical treatment in patient with AN SAH, and we should be also alert to preventable causes of delayed neurological deterioration for improving the outcome in all elderly groups.

• Journal of Korean Neurosurgical Society
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• v.30 no.12
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• pp.1375-1380
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• 2001

Objective : The authors analyzed the incidence, the cause and the prognosis of hydrocephalus following aneurysmal subarachnoid hemorrhage to evaluate the risk factors of hydrocephalus and to provide the proper treatment method for hydrocephalus following aneurysmal subarachnoid hemorrhage. Methods : The 505 cases of subarachnoid hemorrhage followed by aneurysmal surgery from January 1990 to May 1999, were divided into shunt group and shunt-free group and we were reviewed for the clinical status, Fisher's grade, brain CT findings and prognosis. Results : The incidence of acute hydrocephalus was 37.2% of patients and 18.9% to developed chronic hydrocephalus. Shunt surgery due to chronic hydrocephalus was required in 6.5% of patients. We found following variables were significantly related to shunt-dependent hydrocephalus : high Hunt-Hess and Fisher grade, initial CT findings of intraventricular hemorrahge, posterior circulation aneurysm, preoperative rebleeding, delayed ischemic deficits, and initial high ventricular size index. There were no statistically significant relationships between shunt-dependent hydrocephalus and patient age or sex, timing of operation. The previous hypertension was not related to shunt dependent hydrocephalus. Prognosis in shunt group showed poor result. Conclusion : The risk factors of hydrocephalus following aneurysmal subarachnoid hemorrhage are high Hunt-Hess grade, high Fisher's grade, aneurysms of posterior circulations, preoperative aneurysmal rebleeding, delayed ischemic deficits, initial CT findings of intraventricular hemorrahge and initially increased ventricular size. The patients with these factors should the carefully observed and managed accordingly due to poor prognosis related to hydrocephalus requiring shunt operation.

• Korean Journal of Adult Nursing
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• v.15 no.4
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• pp.628-638
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• 2003

Purpose: The purpose of this study was to develope a evaluation tool of the quality of nursing care for aneurysmal subarachnoid hemorrhage patients at Hunt & Hess Grade I~III. Method: The data was gathered from April 15, 2002 to June 14, 2002. The tool proceeded in six steps according to Bloch's framework. Result: The results of this study are as follows: 1) The quality evaluation tool for neurosurgery ICU consisted of 25 standards and 138 criteria. The quality evaluation tool for ward consisted of 27 standards and 144 criteria.; 2) The content validities of the tools for neurosurgery ICU and ward were 0.96 and 0.98, respectively.; 3) The Pearson coefficients for evaluating the interrated reliability of the tools for neurosurgery ICU and ward were r=0.9106 (p<0.1) and r=0.8807 (p<0.1), respectively.; 4) The ranges of corrected item-total correlations for evaluating the construct validity of the tools for neurosurgery ICU and ward were 0.0279~0.9354 and 0.0174~0.9682, respectively.; And 5) The ranges of Cronbach's ${\alpha}$ reliabilities for evaluating the internal consistency reliability of the tools for neurosurgery ICU and ward were 0.6040~0.8554 and 0.6212~0.9584, respectively. Conclusion: The tools developed in this study seem useful in evaluating the quality of nursing care for aneurismal subarachnoid hemorrhage patients at Hunt & Hess Grade I-III.

• Journal of Korean Neurosurgical Society
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• v.48 no.6
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• pp.480-484
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• 2010

Objective : To evaluate the role of lumbar drainage in the prevention of shunt-dependent hydrocephalus after treatment of ruptured intracranial aneurysms by coil embolization in good-grade patients. Methods : One-hundred-thirty consecutive patients with aneurysmal subarachnoid hemorrhage in good-grade patients (Hunt & Hess grades I-III), who were treated by coil embolization between August 2004 and April 2010 were retrospectively evaluated. Poor-grade patients (Hunt & Hess grades IV and V), a history of head trauma preceding the development of headache, negative angiograms, primary subarachnoid hemorrhage (SAH), and loss to follow-up were excluded from the study. We assessed the effects on lumbar drainage on the risk of shunt-dependent hydrocephalus related to coil embolization in patients with ruptured intracranial aneurysms. Results : One-hundred-twenty-six patients (96.9%) did not develop shunt-dependent hydrocephalus. The 2 patients (1.5%) who developed acute hydrocephalus treated with temporary external ventricular drainage did not require permanent shunt diversion. Overall, 4 patients (3.1%) required permanent shunt diversion; acute hydrocephalus developed in 2 patients (50%). There was no morbidity or mortality amongst the patients who underwent a permanent shunt procedure. Conclusion : Coil embolization of ruptured intracranial aneurysms may be associated with a lower risk for developing shunt-dependent hydrocephalus, possibly by active management of lumbar drainage, which may reflect less damage for cisternal anatomy than surgical clipping. Coil embolization might have an effect the long-term outcome and decision-making for ruptured intracranial aneurysms.

• Geophysics and Geophysical Exploration
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• v.14 no.3
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• pp.191-202
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• 2011

Reserve-time migration (RTM) using a two-way wave equation is one of the most accurate migration techniques. RTM has been conducted by assuming that subsurface media are isotropic. However, anisotropic media are commonly encountered in reality. Conventional isotropic RTM may yield inaccurate results for anisotropic media. In this paper, we develop RTM algorithms for vertical transversely isotropic media (VTI) and tilted transversely isotropic media (TTI). For this, the pseudo-acoustic wave equations are used. The modeling algorithms are based on the high-order finite-difference method (FDM). The RTM algorithms are composed using the cross-correlation imaging condition or the imaging condition using virtual sources. By applying the developed RTM algorithms to the Hess VTI and BP TTI models, we could obtain better images than those obtained by the conventional isotropic RTM.