• 수면정신생리
• /
• 제9권1호
• /
• pp.5-8
• /
• 2002

Stroke is a leading cause of death in most developed countries and some developing countries including South Korea. It is well known that stroke has is related in some way with several sleep disorders. At first, the onset time of stroke varies according to circadian rhythm. Early morning is the most prevalent time and late evening the least. The changes of blood pressure, catecholamine level, plasminogen activity and aggregation of platelet during sleep have been suggested as possible mechanisms. Sleep apnea (SA), a representative disorder in the field of sleep medicine, is found in more than 70% of acute stroke patients compared to 2-5% of the general population. Various sleep related breathing disorders occur after stroke and snoring is a distinct risk factor for stroke. So the relationship between stroke and SA is obvious, but the cause and effect are still not clearly known. Also, stroke may cause many sleep related problems such as insomnia, hypersomnia, parasomnia and changes in sleep architecture. Patients, family members and even medical personnel often ignore stroke-related sleep problems, being concerned only about the stroke itself. The clinical impacts of sleep problems in stroke patients may be significant not only in terms of quality of life but also as a risk factor or prognostic factor for stroke. More attention should be paid to the sleep problems of stroke patients.

• Journal of Acupuncture Research
• /
• 제39권1호
• /
• pp.53-58
• /
• 2022

Fat pad syndrome is a knee joint condition/disease where acute or chronic inflammation occurs in the fat pad of the knee joint, and it is a cause of anterior knee pain. Fat pad syndrome usually occurs concurrently with other conditions/diseases to collectively cause anterior knee pain. No study to date has reported the treatment of anterior knee pain solely due to fat pad syndrome. Here, we report a case of fat pad syndrome of the knee joint as the sole cause of anterior knee pain in a 49-year-old woman who received integrated Korean medicine treatments (pharmacopuncture, acupuncture, herbal medicine, deep fascial meridian therapy, and chuna). Using patient-reported pain scale scores, the level of the patient's pain was relieved, and her mobility improved. Integrated Korean medicine treatments could be effective for patients who have fat pad syndrome of the knee joint.

• 항공우주의학회지
• /
• 제30권2호
• /
• pp.66-69
• /
• 2020

Since allergic rhinitis is a disease with a very high prevalence, it is common to find patients with allergic rhinitis among aviation workers. However, they are so afraid that the report of rhinitis will have a negative effect on the evaluation of one's work suitability. Therefore, aviation medical examiners (AMEs) must be able to accurately understand the nature of allergic rhinitis, and confidently explain that appropriate treatment of rhinitis has a positive effect on their performance. In the treatment of allergic rhinitis, there are some medications that may cause drowsiness, which may impair the accuracy and safety of the aviation service. Therefore, AMEs should accurately know safe drugs that do not cause drowsiness and prescribe them to patients. In addition, it is necessary to know exactly whether air workers may receive the latest treatments for allergic rhinitis, such as surgical treatment and immunotherapy, and be able to recommend these treatments appropriately. Therefore, in this paper, we first briefly describe the pathophysiology, genetics, causative antigen, symptoms, diagnosis, and treatment of allergic rhinitis. We also aimed to discuss safe medication and other treatment modalities for allergic rhinitis.

• Structural Engineering and Mechanics
• /
• 제84권5호
• /
• pp.699-706
• /
• 2022

Settlement control techniques are critical for the safety of shield tunnel constructions, especially for facing complex situations. In this study, the shield tunnel structure from Huaita east road station to Heping Road station in Xuzhou metro No.3 line (China) is taken as engineering background, which has various complex problems of the upper-soft and lower-hard composite stratum conditions, twin curve shield tunnels, and underpass the foundation of the piled raft. The deformation characteristics of shield tunnelling passing through buildings are explored. Subsequently, comprehensive research methods of numerical simulation and field measurement are adopted to analyzing the effectiveness of settlement control by using the top grouting technique. The results show that the settlement of the buildings has obvious spatial characteristics, and the hysteresis effect can be obviously observed in soil deformation caused by shield construction. Meanwhile, the two shield constructions can cause repeated disturbances, reducing the soil deformation's hysteresis effect. Moreover, the shield tunnel's differential settlement is too large when a single line passes through, and the shield construction of the outer curve can cause more significant disturbance in the tunnel than the inside curve. Notably, the proposed process control parameters and secondary topgrouting method can effectively control the deformation of the shield tunnel, especially for the long-term deformation.

• 한국분무공학회지
• /
• 제6권3호
• /
• pp.38-44
• /
• 2001

The effect of four diesel fuels with oxygenated agents fuels on spray properties from plain-orifice atomizer was investigated. The oxygenates evaluated were diglyme, MTBE, DEE and DMM and were blended in weights of 5, 10, 15, 20 and 30% in a baseline diesel fuel. The physical properties such as surface tension, density and viscosity are also measured for each blended oxygenated fuels. It was found that changes in physical properties of fuels considered are enough to influence spray properties, i.e. spray angle, spray tip penetration and mean drop size. Spray properties were measured by PMAS(particle motion analysis system) which is employing a point measurement technology. Spray angle increased with increase in oxygenate content. The effect, however, was not great in the higher blend level. The oxygenated fuels produced more shorter spray tip penetration than diesel fuels. SMD was decreased with the increase in blending percent. SMD for DMM and DEE are represented 10.33 and 3.41% decreasing rates respectively. It was found that changes in spray characteristics of oxygenated fuel were easily large enough to impact pollutant emissions. It was clear from this study that spray characteristics of oxygenated fuel is one of possible cause of reducing pollutant emissions. It was clear from this study that spray characteristics of oxygenated fuel is one of possible cause of reducing pollutant emissions from diesel engines when oxygenated fuels is applied.

• 한국가스학회:학술대회논문집
• /
• 한국가스학회 2005년도 추계학술발표회 논문집
• /
• pp.141-145
• /
• 2005

DME (Di-Methyl Ether) is a new clean fuel and an environmental-friendly energy resource, also is recently increasing with an alternative interest because of the industrial use. DME has been shown to have excellent properties as a diesel fuel giving emission level better than ULEV standard. So it has been attracting considerable as an alternative diesel fuel. In this study, we carried out simulation of separation and purification process of demo plant for 101on per day DME production, which cause the effect that is important in productivity, from operation results of pilot plant for 50kg per day DME production. The liquefied stream, which was separated by gas-liquid separator after DME reactor, includes $CO_2$, DME, Methanol and $H_2O$. We established three distillation columns for separation and purification of the stream. $CO_2$ was extracted from the stream by first distillation column, DME was extracted by second column and Methanol was extracted by third column. We investigated and analyzed the effect which the actual operation variables cause in efficiency of process and optimized process, finally we got the DME of purity $100\%$.

• 한국압력기기공학회 논문집
• /
• 제11권1호
• /
• pp.61-68
• /
• 2015

The function of Feed Water Ring is to provide the flow path from Feedwater Nozzle to inside of SG(steam generator). Significant amounts of general FAC on the outside of the Feed Water Ring are not likely due to the low flow velocities in this area. However, on the interior of the Feed Water Ring, there may be areas of local higher flow velocity which could lead to higher FAC rates. These may include the inlet tee from the Feedwater Nozzle into the Feed Water Ring, the areas where the Feed Water Ring changes diameter, and especially the entrance area to the J-Nozzles. In this paper, the results of root cause analysis of through-wall hole observed at domestic WH 51F SG Feed Water Ring and its effect on the integrity and performance of SG are described. And, the maintenance strategy for WH 51F SG Feed Water Ring and the monitoring strategy for Downcomer Feed Water Ring of CE System 80 SG are presented.

• 한국정보시스템학회지:정보시스템연구
• /
• 제31권4호
• /
• pp.123-143
• /
• 2022

Purpose The purpose of this study was to investigate the experience cues of chatbot services provided to existing customers familiar with the e-commerce environment, and to examine the effect of chatbot service's experience cues on customer experience and chatbot trust. Design/methodology/approach This study was conducted on consumers who experienced chatbot services in an e-commerce environment, the final 299 copies of valid data were obtained, and the research hypothesis was verified using PLS as a structural equation model. Findings As a result of the analysis, it was found that functional cues that cause customer experiences using chatbot services had a positive effect on cognitive and emotional experiences, human cues had a positive effect on cognitive, emotional and relational experiences, and customer experiences had a positive effect on chatbot trust.

• Toxicological Research
• /
• 제16권1호
• /
• pp.89-94
• /
• 2000

Alpha-hydroxy acid(AHA) are used in cosmetic products as a pH adjuster, mild exfoliant and humectant-skin conditioner. Cosmetics containing higher concentration (30%) and lower pH (3.0) of AHA can cause side effects if it is applied without the prescription. For providing information on the safety of AHA and on human risk assessments we studied skin irritation effect of glycolic acid, one of the most commonly used AHA in guinea pigs. The skin irritation by glycolic acid was increased in a dose(10% to 70%), acidity (pH 2.5 to 5.5.) and length of exposure dependent manner (for up to 14 days), respectively. The combination treatment with UVB (0.4 or 3.0 J/$cm^2$) increased glycolic acid-induced skin irritation. Histological examination showed that hyperplasia of non-inflammatory cells in the epidermis of skin treated with high dose of glycolic acid (pH 3.0). There results show that glycolic acid increased skin irritation in a dose, length of exposure and pH dependent manner, respectively, in guinea pig, and the combination with UVB increased glycolic acid-induced skin irritation. The cell proliferation of non-inflammatory cell may be involved in high doses of glycolic acid-induced skin irritation. Long-term application of more than 30% of glycolic acid (pH 3.0) may cause skin irritation.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.50-57
• /
• 2010

Various installation faults may lie in fasteners in the construction of a direct-fixation track by the top-down method. At an extreme, they may cause excessive interaction between the train and track, compromise the running safety of the train, and cause damage to the track components. Therefore, the faults need to be kept within the allowable level through an investigation of their effects on the interactions between the train and track. In this study, the vertical dynamic stiffness of fasteners in installation faults was measured based on the dynamic stiffness test by means of an experimental apparatus that was devised to feasibly reproduce gap faults. This study proposes an effective analytical model for a train-track interaction system in which most elements, except the nonlinear wheel-rail contact and some components that behave bi-linearly, exhibit linear behavior. To investigate the effect of the behavior of fasteners in gap faults in a direct-fixation track on the vehicle and track, vehicle-track interaction analyses were carried out, targeting key review parameters such as the wheel load reduction factor, vertical rail displacement, rail bending stress, and mean stress of the elastomer. From the results, it was noted that the gap faults in the concrete bearing surface of a direct-fixation track need to be limited for the sake of the long-term durability of the elastomer than for the running safety of the train or the structural safety of the track.