• 한국해양공학회지
• /
• 제4권1호
• /
• pp.88-100
• /
• 1990

Among the test methods to evaluate stress-corrosion cracking(SCC) on the basis of fracture mechanics, constant displacement(bolt) loading method using modified-WOL specimen is practically convenient. In this test method, compliance formula is generally required to calculate load(consequently $K_{ISCC}$). There are many problems in using the analytic compliance formula to calculate $K_{ISCC}$, so we had proposed the experimental $K_{ISCC}$ evaluation technique in the previous report. This study has employed the slightly altered configuration of modified-WOL specimen made of weldable structural stee(BS360-50D). With these specimens, stress-corrosion tests have been performed in $H_2S$ gas saturated 20% HCl solution. Through the test, the problems as mentioned earlier have been discussed again, and the proposed evaluation technique has been verified. And the stress-corrosion cracks and hydrogen blisters have been investigated in the initiation step with the aids of metallurgical micrographs, SEM fractographs, and EPMA analysis. The inclusions segregated in the mid-thickness region traps hydrogen to produce the hydrogen blistering. The applied or residual stress does not contribute the occurrence of the blister. Hydrogen absorbed into the mid-thickness region is consumed to produce the blistering so that stress-corrosion crack could hardly be detected at that region. The stress-corrosion cracks initiate from the inclusions and propagate in radial pattern. And the initiation site is remote from the crack tip and is inclined from the crack plane, which is assumed to be caused by the triaxial stress and the amount of the absorbed hydrogen.

• 한국도로학회논문집
• /
• 제15권3호
• /
• pp.103-115
• /
• 2013

PURPOSES: The purpose of this study is to develop a method for distribution between superelevation and side friction factor by increasing design speed. METHODS: First of all, a method for distribution between superelevation and side friction factor and a theory for the functional formula of side friction factor in compliance with horizontal radius applied in South Korea and the United States are considered. Especially, design speed of 140km/h and numerical value of design elements are applied to the theory for the functional formula of side friction factor in AASHTO's methods. Also, the anxiety EEG upon running speed is measured to reflect ergonomic characteristics through field experiments at seven curve sections of the West Coast Freeway, and this data is applied to graph for the functional formula of side friction factor. RESULTS : Matching side friction factor against the anxiety EEG, the results that a critical points of driver's anxiety EEG sharply increase locate under existing parabola are figured out. CONCLUSIONS : Therefore, we could get a new type of the functional formula that driver's driving comfortability is guaranteed if the existing the functional formula of side friction factor goes down under boundary of the critical points of the anxiety EEG.

• 대한한의학방제학회지
• /
• 제16권1호
• /
• pp.131-145
• /
• 2008

With tablets and powder, decoction has been a widely-used method of medicine formula. However, for these formulas have unique bitter tastes and flavors of herbal component materials as it is, the compliance of herbal medicine is severly decreased especially for female and younger patients. Consequently, expected treatment effects can't be acquired completely. If loathsome tastes and flavors of decoction were effectively reduced while pharmacological activity were kept intact, the compliance could be promoted Chong-Myung-Tang has been widely prescribed for student patients with memory This study shows that Chong-Myung-Tang+chocolate have no difference from Chong-Myung-Tang in terms of pharmacological activity. Sensory difference with net chocolate was also surved. In order to observe the difference of Chong-Myung-Tang+chocolate and Chong-Myung-Tang, memory impairment was induced by intraventricular injection of $A{\beta}_{25-35}$ peptides on mice and Chong-Myung-Tang and Chong-Myung-Tang+chocolate were administered orally for 14 days. In water maze task, improvement of learning ability during acquisition period and significant increase of memory score during retention period resulted from the treatment of Chong-Myung-Tang and Chong-Myung-Tang+chocolate with respect to the $A{\beta}-injected$ control animals. Furthermore, the $A{\beta}_{25-35}$ toxicity on the hippocampus was assessed with immunohistochemistry (Bax, TUNEL), and differences in antioxidant activity was observed through TBARS and DPPH test. We employed sensory tests using chocolate flavor, herb flavor, and bitter taste & hardness as standards to show sensory differences with net chocolate. In this study, it is demonstrated that Chong-Myung-Tang+chocolate do not disturb the pharmacological activity of Chong-Myung-Tang, and have no sensory difference with net chocolate. Chong-Myung-Tang+chocolate can be used to enhance the compliance remarkably and thought of as an effective, functional formula to maximize expected treatment.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1998년도 추계학술대회 논문집
• /
• pp.279-286
• /
• 1998

Fatigue crack propagation behavior for variable load in high strength aluminum alloys was investigated in this study. The materials used in this study are aluminum 7075-T651 and 5052-H32 alloys. Crack length was measured from calibration curve, which was plotted by known crack length and resistance of standard specimens. Load was obtained from linear regression formula. Unloading elastic compliance method was ap;ied to check the crack closure and cracked area.

• 한국자동차공학회논문집
• /
• 제19권1호
• /
• pp.25-31
• /
• 2011

The purpose of the study is to enhance the vehicle handling stability of the PACE formula vehicle. Required data for the dynamic analysis of the vehicle are as follows: Mass, moment of inertia, and tire's dynamic properties. Mass and moment of inertia data were calculated using Siemens NX 5.0 which results were verified with VIMF measurements of GMDAT. Dynamic data for the tire were supplied by Kumho Tire. Aerodynamic forces play an important role in the formula vehicle which forces were calculated by using Fluent. Full vehicle dynamic analysis using Carsim software has been carried out to find out the improvement of the vehicle stability by changing the shapes of the rear wing.

• Tribology and Lubricants
• /
• 제31권4호
• /
• pp.163-169
• /
• 2015

This paper describes a design method for the corner radius of a contacting body using the theoretical approach of contact mechanics. A complete contact, as in the case of a sharp-cornered punch, produces singular contact traction: whereas, in an incomplete contact, the singular contact traction disappears because of the rounded corners, and the contact edges are within the rounded regions. The design method aims to determine the conditions of the contact force as well as the material properties in an incomplete contact. The incomplete contact changes into the complete contact again when the contact edges exceed the rounded regions owing to either an increased contact force or the compliance of the materials. The contact length of a rounded punch is used as a parameter to derive the required conditions. As a result, a design formula is obtained, which provides a minimum allowable radius when the materials, normal contact force, and the length of a flat region of the punch are predetermined. This work consists of two parts: Part I includes a theoretical background, design method, and formula, and Part II describes the actual process with the investigation of design parameters.

• 대한상한금궤의학회지
• /
• 제10권1호
• /
• pp.125-132
• /
• 2018

Objective : The purpose of this study is to review a case of hypertension. The patient was 41 years, a male. We stabilized blood pressure after administration of Daehuanghuanglianxiexin-tang. In this paper, we review the interpretation of Shanghanlun by analyzing the patient's progress, diagnosis, treatment. Methods : Blood pressure changes have been monitored during the period. Additionally, We have observed the patients' compliance and accompanied symptom by the timeline analysis. Results : According to Shanghanlun disease pattern identification diagnostic system, Wediagnosed a Greater yang disease. The patient was treated with Daehuanghuanglianxiexin-tang for 2 months. Daehuanghuanglianxiexin-tang was able to control blood pressure to under 120mmhg / 80mmhg. During the treatment period, the accompanied symptom Stiffness and pain in posterior neck has improved, patient's compliance was good, and symptoms improved without significant complication Conclusions : Taking of the Daehuanghuanglianxiexin-tang makes patient's blood pressure controlled to safe and stable range and eases the discomfort of posterior neck pain.

• 대한한의학회지
• /
• 제32권3호
• /
• pp.18-24
• /
• 2011

Objective: Leejung-tang (Rechu-to in Japanese) is a traditional Korean herbal formula used for treatment of gastrointestinal disorders such as vomiting, stomach pain, chronic gastritis and gastrointestinal ulceration. The present study was carried out to investigate the potential acute toxicity of Leejung-tang water extract (LJT) by a single oral dose in Crl:CD (SD) rats in compliance with current guidelines. Methods: In the preliminary study, there were no adverse effects such as death, clinical signs, and body weight changes at dose levels of 500, 1000, and 2000 mg/kg/day body weight. Based on the results, a dose of 2000 mg/kg was selected as the toxicological limited dose. LJT was administered once by gavage to male and female rats at dose levels of 0 and 2000 mg/kg bodyweight. During the study period, mortalities, clinical findings, and body weight changes were observed for 14 days following the administration. On day 14 after the treatment, the animals were sacrificed by carbon dioxide overdose and complete gross postmortem examinations were performed. Results: In present study, no treatment-related deaths were observed. There were no adverse effects on clinical signs and body weight changes. In addition, there were no observed gross findings in all groups except for a kidney cyst in the 2000 mg/kg/day female group. Conclusion: The results indicated that LJT did not induce toxic effects at a dose level up to 2000 mg/kg in rats and its median lethal dose ($LD_{50}$) was considered to be over 2000 mg/kg/day body weight for both genders.

• 대한기계학회논문집
• /
• 제15권6호
• /
• pp.1792-1798
• /
• 1991

본 연구에서는 균열 끝을 포함하는 선 적분을 행하여 $J_{k}$ 구한 다음 이방 성 재료에서의 탄성계수 상호간의 관계를 이용하여 $J_{k}$를 탄성계수와 응력확대계 수 $K_{I}$, $K_{II}$ 로 간단히 표현 하고자 한다. 이 결과는 선형탄성 이방성 재 료에서 수치적으로 응력확대계수를 구하는 데 있어 기초 자료로 활용 될 것으로 생각 된다.다.다.다.

• 대한상한금궤의학회지
• /
• 제11권1호
• /
• pp.83-94
• /
• 2019

Objective : There was an improvement in a patient with psoriasis following the intake of Hoeyeok-tang for 317 days. By analyzing these cases, we reviewed the use of Hoeyeok-tang in skin diseases and attempted to interpret the related Shanghanlun articles. Methods : The diagnostic process was analyzed according to the disease pattern identification diagnostic system based on the Shanghanlun provisions. The progression of psoriasis, which was addressed, was assessed using the PASI score. Results : The patient was diagnosed with Soeum-byung 324, and the PASI score decreased from 13.6 to 0.4 after the intake of Hoeyeok-tang for 317 days. The patient's compliance and expectation from treatment were good, and no specific adverse effect was identified. Conclusions : This study suggests the clinical use of Hoeyeok-tang in psoriasis based on Shanghanlun.