• Ocean Systems Engineering
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• 제3권3호
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• pp.237-255
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• 2013

In many applications, Remotely Operated Vehicles (ROVs) are required to be capable of course keeping, depth keeping, and height keeping. The ROV must be able to resist time-variant external forces and moments or frequent manipulate changes in some specified circumstances, which require the control system meets high precision, fast response, and good robustness. This study introduces a Fuzzy-Incomplete Derivative Ahead-PID (FIDA-PID) control system for a 500-meter ROV with four degrees of freedom (DOFs) to achieve course, depth, and height keeping. In the FIDA-PID control system, a Fuzzy Gain Scheduling Controller (FGSC) is designed on the basis of the incomplete derivative ahead PID control system to make the controller suitable for various situations. The parameters in the fuzzy scheme are optimized via many cycles of trial-and-error in a 10-meter-deep water tank. Significant improvements have been observed through simulation and experimental results within 4-DOFs.

• Structural Engineering and Mechanics
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• 제62권5호
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• pp.551-565
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• 2017

Based on the strain gradient theory (SGT), vibration analysis of an embedded micro cylindrical shell reinforced with agglomerated carbon nanotubes (CNTs) is investigated. The elastic medium is simulated by the orthotropic Pasternak foundation. The structure is subjected to magnetic field in the axial direction. For obtaining the equivalent material properties of structure and considering agglomeration effects, the Mori-Tanaka model is applied. The motion equations are derived on the basis of Mindlin cylindrical shell theory, energy method and Hamilton's principal. Differential quadrature method (DQM) is proposed to evaluate the frequency of system for different boundary conditions. The effects of different parameters such as CNTs volume percent, agglomeration of CNTs, elastic medium, magnetic field, boundary conditions, length to radius ratio and small scale parameter are shown on the frequency of the structure. The results indicate that the effect of CNTs agglomeration plays an important role in the frequency of system so that considering agglomeration leads to lower frequency. Furthermore, the frequency of structure increases with enhancing the small scale parameter.

• 한국환경보건학회지
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• 제40권2호
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• pp.157-170
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• 2014

Objectives: Agent Orange TCDD has been related to serious diseases among Korean veterans who were exposed to it. Decades after the end of the war, however, its effects are still being debated. The object of this study was to examine various unmet needs raised among Agent Orange exposed veterans and their families and to find grounds of a new welfare policy for providing alternative legislation. Methods: Literatures concerning Agent Orange, TCDD, the associated diseases, compensation for veterans and Supreme Court sentencing were searched using PubMed, ProQuest, press news and relevant homepages. Results: Agent Orange exposed veterans are eligible for various benefits from the government, including disability compensation for diseases associated with exposure. The Ministry of Patriots and Veterans Affairs has classified certain diseases into two categories, Agent Orange sequela diseases and sequela suspect diseases and has provided differential benefits based on separated laws. Big differences exist in benefits to veterans and their families between the two laws. The absence of definite standards to classify the Agent Orange associated diseases was confirmed by recent Supreme Court sentencing which ruled in favor of US manufacturers. Conclusion: It appears that the evidence for cause and effect of Agent Orange related diseases would never be perfect. The results suggest a need to change welfare principles from presumptive or indefinite disease basis to exposure experiences combined with integrated disability evaluation. We propose to extend eligibility by enacting a new law for Agent Orange exposed Korean veterans.

• Tuberculosis and Respiratory Diseases
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• 제39권1호
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• pp.103-108
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• 1992

Pulmonary paragonimiasis is the infectious disease of lung, due to 'Paragonimus westermani'. The clinical manifestations are various, and the main symptoms are chronic cough and persistent hemoptysis. Radiological findings mainly include thin walled cyst, migrating patch pulmonary infiltration, transient linear shadow, and hydropneumothorax, etc. The differential diagnosis should include pulmonary tuberculosis, pneumonia, other parasitic diseases, and rarely lung malignancy if the mass-like lesion is present. Recently, the incidence of paragonimiasis is very low. But the physicians should suspect paragonimus infection, if the patient has chronic respiratory symptom such as hemoptysis and lives in the endemic area such as Korea. A case of pulmonary paragonimiasis confirmed by histological basis of lung was presented with a review of the literature.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1996년도 The 9th KACG Technical Annual Meeting and the 3rd Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.139-156
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• 1996

The phase field model is becoming the model of choice for the theoretical study of the morphologies of crystals growth from the melt. This model provides an alternative approach to the solution of the classical (sharp interface) model of solidification by introducing a new variable, the phase field, Ø, to identify the phase. The variable Ø takes on constant values in the bulk phases and makes a continuous transition between these values over a thin transition layer that plays the role of the classically sharp interface. This results in Ø being governed by a new partial differential equation(in addition to the PDE's that govern the classical fields, such as temperature and composition) that guarantees (in the asymptotic limit of a suitably thin transition layer) that the appropriate boundary conditions at the crystal-melt interface are satisfied. Thus, one can proceed to solve coupled PDE's without the necessity of explicitly tracking the interface (free boundary) that would be necessary to solve the classical (sharp interface) model. Recent advances in supercomputing and algorithms now enable generation of interesting and valuable results that display most of the fundamental solidification phenomena and processes that are observed experimentally. These include morphological instability, solute trapping, cellular growth, dendritic growth (with anisotropic sidebranching, tip splitting, and coupling to periodic forcing), coarsening, recalescence, eutectic growth, faceting, and texture development. This talk will focus on the fundamental basis of the phase field model in terms of irreversible thermodynamics as well as it computational limitations and prognosis for future improvement. This work is supported by the National Science Foundation under grant DMR 9211276

• 한국응용곤충학회지
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• 제11권1호
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• pp.41-43
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• 1972

1) 수도 도열병에 저항성이었던 관옥 품종이 1969년에 와서 저항성이 역전된 원인을 분석하였다. 2) 경기도지방 16개 지역의 이병된 관옥품종에서 분리한 균주는 15개의 C계통 레이스와 1개의 N계통 레이스로 판정되었다. C계통 레이스 중에는 C-8이 9균주, C-7과 C-1이 각각 2균주, 그 나머지는 C-1과 유사한 것이 1균주이고 C-5와 유사한 것이 1균주였다. 3) 도열병에 대하여 고도로 저항성이었던 관옥품종은 중국계통의 벼를 침해 한 수 있는 C레이스의 만연에 기인되었다고 결론지을 수 있다.

• 대한세포병리학회지
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• 제4권2호
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• pp.127-132
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• 1993

Ki-1 lymphoma is a sort of high grade large cell lymphoma and defined on the basis of the reactivity of the tumor cells with monoclonal antibody Ki-1. On fine needle aspiration cytology, the reported case is rare and the differential diagnosis is not easy, especially from undifferentiated carcinoma and Hodgkin's lymphoma. We experienced a case of fine needle aspiration cytology of Ki-1 positive large cell lymphoma in a 61-year old male patient. Fine needle aspiration cytology from the cervical lymph node disclosed hypercellular smears with large single cells on polymorphous lymphoid background. The tumor cells had abundant dense cytoplasm and large nuclei with Irregular profiles. Although most cells were mononuclear binucleated and multilobed/multinucleated cells were also seen Immunohistochemistry was done and revealed strong positive staining for Ki-1 antigen.

• 한국지구과학회지
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• 제30권5호
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• pp.671-681
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• 2009

In the equilibrium theory of tides by Newton, tide on the Earth is a phenomenon driven by differential gravity contributed both by the Sun and the Moon. Due to the direct link of the generic tidal effect to the oceanic tides, college students in the earth science education department are exposed to this theory through oceanography lectures as well as astronomy lectures. Common oceanography textbooks adopt a non-inertial reference frame fixed to the Earth in which the fictitious, centrifugal force appears. This has a potential risk to provide misconceptions among students in various aspects including the followings: 1) this is how Newton originally derived the equilibrium theory of tides, and 2) the tide is a phenomenon appearing only in rotating systems. We show that in astronomy, a much simpler description, which employs the inertial frame, is generally used to explain tides and thus causes less confusion. We argue that the description used in astronomy is preferable both in the viewpoints of simplicity and ease of interpretation. Moreover, on a historical basis, an inertial frame was adopted by Newton in Principia to explain tides. Thus, the description used in astronomy is consistent with Newton's original approach. We also present various astrophysical tides which do not comply with the concept of centrifugal force in general. We therefore argue that the description used in oceanography should be compensated by that in astronomy, due to its complexity, historical inconsistency and limited applicability.

• Journal of Yeungnam Medical Science
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• 제31권1호
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• pp.21-24
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• 2014

Clinical presentation of Bartter syndrome is similar to surrepitious vomiting or use of diuretics. Therefore, precise differential diagnosis of Bartter syndrome is crucial. We report a case of medullary nephrocalcinosis (MNC) induced by furosemide mimicking Bartter syndrome. A 55-year-old female patient visited our hospital with renal dysfunction on basis of hypokalemia and metabolic alkalosis. She had no history of hypertension or drug use except allopurinol and atorvastatin. She did not complain of nausea or vomiting on presentation and the serum magnesium level was normal. We performed ultrasonography, that showed MNC. For these reasons, we suspected Bartter syndrome and corrected the electrolyte imbalance. During outpatient follow up, we found that the patient had been taking 400 mg of furosemide daily for 30 years. We could diagnose furosemide induced MNC, and recommended to her to reduce the amount of furosemide.

• 대한기계학회논문집B
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• 제28권5호
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• pp.526-534
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• 2004

A new second-moment closure model for turbulent heat fluxes is proposed on the basis of the elliptic equation. The new model satisfies the near-wall balance between viscous diffusion, viscous dissipation and temperature-pressure gradient correlation, and also has the characteristics of approaching its respective conventional high Reynolds number model far away from the wall. The predictions of turbulent heat transfer in a channel flow have been carried out with constant wall heat flux and constant wall temperature difference boundary conditions respectively. The velocity field variables are supplied from the DNS data and the differential equations only fur the mean temperature and the scalar flux are solved by the present calculations. The present model is tested by direct comparisons with the DNS to validate the performance of the model predictions. The prediction results show that the behavior of the turbulent heat fluxes in the whole region is well captured by the present model.