• 한국환경과학회지
• /
• 제8권6호
• /
• pp.639-643
• /
• 1999

After analyzing the correlation between air pollution and visibility, TSP and $NO_2$ is responsible for poor visibility in Pusan. After analyzing the correlation between meteorological factors and visibility, general pattern of humidity has clear negative correlation. The variation of wind speed has a positive correlation. In order to investigate the cause of poor visibility in Pusan area, the Andersen sampler and PM-2.5 are used to collect and analyze aerosol. This study was carried out to monitor the visibility using Forward scattering meter and to find out the characteristics and the cause of good visibility case and poor visibility case by measuring and analyzing a variety of parameters, such as particle size distributions, chemical compositions, and meteorological conditions in Pusan. According to the analysis of intensive sampling, $NO_3^-,NH_4^+$ ion concentration increased together with the mass concentration around $0.5\~2.5{\mu}m$ approximately during the case of poor visibility. $NH_4NO_3,\;NH_4Cl,\;and\;NaCl$ were thought to be the major components of fine particles.

• 한국항해항만학회지
• /
• 제27권1호
• /
• pp.15-30
• /
• 2003

연안 경비함정의 선상근무 환경은 육상근무 환경에 비하여 매우 열악하여 선상근무 기피와 성원고령화의 원인이 되고 있다. 특히 선박내 소음은 난청과 같은 직업병을 유발시키는 원인이 된다. 따라서 안락한 선상근무 환경 및 거주 환경의 확보를 통하여 선상근무 피로도를 경감시키는 것이 필요하다. 본 연구에서는 먼저 선박내 소음 및 진동의 실선 계측을 통하여 선상근무 환경을 체계적으로 평가한다. 그리고 선상근무 환경의 평가 결과에 기초하여 선상근무 피로도 경감대책을 제안한다

• Journal of Power Electronics
• /
• 제11권6호
• /
• pp.914-921
• /
• 2011

Commencing with incandescent light bulbs, every load today creates harmonics. Unfortunately, these loads vary with respect to their amount of harmonic content and their response to problems caused by harmonics. The prevalent difficulties with harmonics are voltage and current waveform distortions. In addition, Electronic equipment like computers, battery chargers, electronic ballasts, variable frequency drives, and switching mode power supplies generate perilous amounts of harmonics. Issues related to harmonics are of a greater concern to engineers and building designers because they do more than just distort voltage waveforms, they can overheat the building wiring, cause nuisance tripping, overheat transformer units, and cause random end-user equipment failures. Thus power quality is becoming more and more serious with each passing day. As a result, active power filters (APFs) have gained a lot of attention due to their excellent harmonic compensation. However, the performance of the active filters seems to have contradictions with different control techniques. The main objective of this paper is to analyze shunt active filters with fuzzy and pi controllers. To carry out this analysis, active and reactive current methods ($i_d-i_q$) are considered. Extensive simulations were carried out. The simulations were performed under balance, unbalanced and non sinusoidal conditions. The results validate the dynamic behavior of fuzzy logic controllers over PI controllers.

• 한국추진공학회지
• /
• 제17권6호
• /
• pp.1-10
• /
• 2013

본 연구에서는 다이아프램이 설치된 하이브리드 로켓 모터에서 발생하는 큰 압력진동의 가진 요인을 분석하였다. 다이아프램 유 무와 다이아프램 직경, 산화제 유량, 연료 길이 등의 다양한 실험조건을 고려하여 하이브리드 로켓 모터 추진시험을 수행하였고, 하이브리드 로켓 모터 가시화 장치를 이용하여 다이아프램이 삽입된 연소기의 내부 연소장을 가시화 하였다. 이러한 실험을 통해 주요 연소실 압력 가진 요인은 hole-tone인 것으로 판단되고, hole-tone 모델로 예측한 주파수와 추진 시험을 통해 획득한 주요 압력진동 주파수가 잘 일치함을 확인하였다.

• 한국치위생학회지
• /
• 제20권3호
• /
• pp.281-290
• /
• 2020

Objectives: Stress is the cause of several illnesses, in older people, stress may also cause various social problems. The oral health of older adults is closely related to the quality of life, and chewing ability is particularly important for their general health. The purpose of this study was to investigate the relationship between stress, the number of teeth remaining, and the chewing ability, which reflects the oral health status among older adults. Methods: This study evaluated the stress level and chewing ability of adults older than 65 years using the 6th (2014-2015) Korea National Health and Nutrition Examination data. The total number of remaining teeth was determined based on the data of the teeth conditions. Results: There was an association between stress and chewing ability among older adults. The odds ratio of chewing function increased by 2.67 times (crude OR=2.67; 95% CI=1.88-3.79) with increased stress. After adjusting, the odds ratio increased to 2.74 times (adjusted OR=2.74; 95% CI=1.88-3.98). Conclusions: Reducing stress may facilitate effective oral health management and improve the overall quality of life in older adults. The findings of this study may help in the discovery of various approaches s to reducing stress in older adults and provide relevant information for oral health education.

• 대한한방내과학회지
• /
• 제18권2호
• /
• pp.112-130
• /
• 1997

This study has been carried out to investigate the cause, pathological mechanism and treatment of stroke in Oidaibiyo(外臺秘要), written by Wangdo(王燾). The results were follows : 1. Oidaibiyo(外臺秘要), which is written by Wangdo gives an account of the symptomatic degree of intensity and diachronic procedure in the chapter of stroke. 2. The cause of stroke is quoted mainly from External Wind(外來風邪), and the hyper-sexual intercourse, hyperalimentation, hyper -consciousness, excessive lavour and so forth as additional. And personal character and external effect, like the climate conditions are also much affected the outbreak of stroke. 3 With respect to the diagnosis of stroke, pulse means here quoted from its conception in Chungumyobang(千金要方) Jebungwonhuron(諸病源候論), and pulse plays an important role in diagnosis of stroke. 4. The treatment for stroke generally attaches much importance to medicine therapy. The concrete cure, BalhanGeopungbub(發汗祛風法) has been mainly available, and the usage of Cheongyulyak(淸熱樂) has been increased, contray to formal.

• 약학회지
• /
• 제57권1호
• /
• pp.43-54
• /
• 2013

Viral hepatitis is the inflammation of liver cells caused by viruses, and still one of the major health-care problems worldwide. A number of viruses to cause hepatitis are type A, B, C, D, E or G. Among these viruses leading to hepatitis, B and C are more troublesome being more prone to chronic illness which can cause the potentially fatal conditions of hepatocellular carcinoma (HCC) and/or liver failure. If immediate treatment is not initiated, liver transplant is the only option left. Over the past few decades there has been remarkable progress in diagnose and monitor all hepatitis virus infections for treatment and prevention. Nonetheless, important challenges remain to develop more effective and safe vaccines for prevention as well as antiviral agents to reduce viremia/viral load by inhibiting viral replication. The development and evaluation of antiviral agents through carefully designed clinical trials over the last 25 years has heralded a new dawn in the treatment of patients chronically infected with the hepatitis B and C viruses, but not so for the D virus. The introduction of Direct Acting Antivirals (DDAs) for the treatment of HBV carriers has permitted the long term use of these compounds for the continuous suppression of viral replication. This review aims to summarize the current status and development approaches of antiviral drugs for the treatment of viral hepatitis and future perspectives.

• 대한족부족관절학회지
• /
• 제25권1호
• /
• pp.6-9
• /
• 2021

The term chronic lateral ankle instability (CLAI) embraces a spectrum of conditions that involve functional and mechanical instability, both in athletes and lower-demand patients. The hallmarks of CLAI are recurrent sprains, persistent pain, and repeated episodes of the ankle giving way. CLAI is the main complication of acute ankle sprains, which can cause discomfort in daily and sports activity. Approximately 10% to 30% of patients with acute ligament ruptures will develop chronic instability over the course of a year from the index injury. An accurate diagnostic approach and successful treatment plan should be established based on a comprehensive understanding of the concept of functional and mechanical instability. Unfortunately, the optimal modality for the management of CLAI is unclear. Even after conservative treatment or surgical intervention, it could result in degenerative changes to the ankle joint in the long term. Thus far, the incidence of ligamentous posttraumatic ankle osteoarthritis was reported to be 13% to 78%. The mean latency time between injury and osteoarthritis was at least 10 to 34.3 years. CLAI is an important pathological condition that can cause discomfort or dysfunction in daily activity in the short term, resulting in joint destruction in the long term. Therefore, it is important to understand the various complications that can occur when CLAI is not treated properly.

• 대한의생명과학회지
• /
• 제25권1호
• /
• pp.66-74
• /
• 2019

Hyperlipidemia is defined as conditions of the accumulation of lipids such as free fatty acids (FFA), triglyceride (TG), cholesterol and/or phospholipid in the bloodstream. Hyperlipidemia can cause lipid accumulation in non-adipose tissue, which is lipid-cytotoxic effects in many tissues and mediates cell dysfunction, inflammation or programmed cell death (PCD). TG is considered to be a major cause of atherosclerosis through inflammatory necrosis of vascular endothelial cells. Recently, TG have also been shown to exhibit lipid-cytotoxicity and induce PCD. Therefore, we investigated the effect of TG on the cytotoxic effect of various cell types. When exposed to TG, the cell viability of U937 monocytes and Jurkat T lymphocytes, as well as the cell viability of MCF-7, a non-immune cell, decreased in time- and dose-dependent manner. In U937 cells and Jurkat cells, caspase-9, an intrinsic apoptotic caspase, and caspase-8, an extrinsic apoptotic caspase, were increased by exposure to TG. However, in TG-treated MCF-7 cells, caspase-8 activity increased only without caspase-9 activity. In addition, the reduction of cell viability by TG was recovered when all three cell lines were treated with pan-caspase inhibitor. These results suggest that activation of apoptotic caspases by TG causes lipotoxic effect and decreases cell viability.

• 한국염색가공학회지
• /
• 제32권4호
• /
• pp.232-238
• /
• 2020

Duck down is a feather of waterfowl and is used as an accessory for bedding products such as evil, pillow and outdoor sleeping bags due to its soft and bulky characteristics. Down is used mainly for winter outdoor such as padding and jumpers because of its excellent thermal insulation effect. Down wear is known as a product with high added value. Down is processed and sanitized because a large amount of oil and fat, bacteria, dust, insects, and soil are mixed. In particular, if the proper amount of oil and fat is not removed, it may cause odor or bacteria, and since the fishy smell peculiar to down and harmful VOCs (toluene, benzene, etc.) are released, there is a need to suppress the occurrence of bacteria through the provision of antibacterial function. In this study, we investigated the substances that cause the fishy odor of down, and confirmed the effect on the deodorization and antibacterial properties of down according to processing agents and processing conditions in order to impart deodorant and antibacterial properties to down.