• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.2
• /
• pp.238-246
• /
• 2021

Collision of small vessels such as fishing boats cause great personal injury. Prior to this study, the collision prevention algorithm was developed to assess the collision risk and make the collision alarm. However, a service provided for safety, such as a collision warning, not only prevents risks, but also requires a certain degree of user satisfaction to function effectively. In this study, the collision prevention algorithm for small vessels was improved to be more practical, and the effects of the improvement were confirmed by applying the algorithm. A survey conducted on the users of the collision warning service confirmed the user requirements for improving the accuracy of the collision warning system and reducing the volume and number of alarms. Accordingly, the algorithm was improved for user satisfaction, and the actual vessel experiment was performed applying the improved algorithm in an actual maritime environment. As a result, the frequency of alarm occurrence decreased compared to former algorithm, but the alarm was relatively steadily generated in dangerous situations. It was analyzed that the accuracy and practicality of the collision alarm were improved. If the practicality and reliability of the improved algorithm are verified in the further study, it will be able to effectively contribute to the prevention of collisions of small vessels.

• Journal of Sasang Constitutional Medicine
• /
• v.7 no.2
• /
• pp.59-88
• /
• 1995

Three groups have participated in this study. 1) The first group consists of 57 patients were who had been treated in the Oriental Medical Hospital at Kyung Hee Medical Center. 2) The second group consists of 37 outpatients who had been treated in the Oriental Medical Hospital at Kyung Hee Medical Center. 3) The third group consists of 76 students of the Oriental Medical School at Kyung Hee University. The following conclusions were made in comparison with EAV measurement values, SaSang Constitution Classfication and CVA. 1. The following conclusions were made in comparison with EAV measurement values and Type(SaSang Constitution Classfication). 1) The analsis of the Correlation in Normal group with EAV measurement values and Type(SaSang Constitution Classfication). 2) The analysis of the correlation in patient group with EAV measurement values showed significant differences in Right meridians(Nerval degeneration vessel, Circulation, Allergy) and in Left meridian(Liver). 3) The analysis of the correlation in Total(Normal+patient)group with EAV measurement values showed significant differences in Right meridians(Large intestine, Nerval degeneration vessel, Circulation, Allergy, Pancreas) and in Left meridians(Lymph vessel, Nerval degeneration vessel, Spleen, liver). 4) The above results showed common-significant differences in Right Allery meridian and in Left Liver meridian. 2. The analysis of the correlation in EAV measurement values and Group (Cerebrovascular accident) showed significant differences in Right meridians(Lymph vessel, Lung, Nerval degeneration vessel, Allergy, Paren & Epith. degeneration vessel, Triple warmer, Heart, Pancreas, Stomach, Fibroid degeneration vessel, Skin, Fatty degeneration vessel, Heart, Stomach, Fibroid degeneration vessel, Skin, Fatty degeneration vessel, Bile duct, Kidney). 3. The analysis of the correlation in EAV measurement values and Para(GROUPS according to PARALYSIS)showed significant differences in Left Stomatch meridian. The analysis of the correlation in EAV measurement values and Para(GROUPS according to PARALYSIS) about the differance of right measurement values and left measurement values showed significant differences in Nerval degeneration vessel, Stomatch, Gall bladder & Bile duct, Kidney and Urinary Bladder meridians. 4. The analysis of the correlation in EAV measurement values and Compl(GROUPS according to COMPLICATION with CVA)showed significant differences in Right meridians(Lymph vessel, Articular degeneration vessel, Fatty degeneration vessel) and in Left meridians(Lung, Stomatch, Fatty degeneration vessel). 5. The analysis of the correlation in Type and MORPHOROGICAL DIAGRAMING (HTOUPS according to MORPHOROGY) showed significant differences in Cranium region, Chest region, Stomatch region and Umbilicum region. 6. The analysis of the correlation in BAZ measurement values and Group(Cerebral Vascular Attack)showed significant differences, the analysis on the correlation of BAZ measurement values and Type(SaSang Constitution Classfication) didn't show any significant differences. 7. In comparison with Actual measurement vales and Voll's measurement values, BAZ measurement values agree with Voll's measurement values but CMP measurement values lower than the Voll's measurement values. Later We have to research further about classifications of race, age, sex etc. The EAV measurement values have Group(Cerebrovascular accident) more correlative than Type(SaSang Constitution Classfication). The EAV may well be that it will be used as an accessory method in SaSang Constitution Classfication and as a diagnostic method in medicine too.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.8
• /
• pp.67-73
• /
• 2019

An ultra-high pressure treatment device is a device used for increasing the shelf life of food by sterilizing it by applying hydrostatic pressure to solid or liquid food. The ultrahigh pressure treatment system developed in this study is a pressure vessel with a processing capacity of 100 L and a maximum pressure of 700 MPa. Pressure vessels for ultrahigh-pressure processing equipment are manufactured using wire-winding techniques. The design formula for making ultra-high pressure vessels with wire windings is given in ASME Section VIII - Division 3. In this study, the ratio of the cylinder to the winding area that can be applied in a wire-winding application was analyzed using a finite element analysis. Furthermore, the relationship between the variation of the residual stress in the vessel and the ratio of the winding area due to the variation of the winding tension was analyzed, and a design guide applicable to the actual product design was developed. Finally, the design equation was modified by presenting the coefficients to correct the difference between the finite element analysis and the design equation.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.15 no.1
• /
• pp.71-76
• /
• 2019

Actual stress distributions in the nozzle of a pressure vessel may not be in plane strain condition, implying that the crack-tip constraint condition may be relaxed in the nozzle. In this paper, a methodology for evaluating the fracture toughness of the ASME Code is presented considering the relaxation of the constraint effect in the nozzle of the reactor pressure vessel. The crack-tip constraint effect is quantified by the T-stress. The equation, which represent the relation between the fracture toughness in the lower constraint condition and the plane strain fracture toughness, is derived using the T-stress. This equation is similar to the method for evaluating the fracture toughness of the Master Curve for low constraint conditions. As a result of evaluating the fracture toughness considering the constraint effect in the reactor inlet, outlet and direct injection nozzles using the proposed equation, it was confirmed that the fracture toughness in the nozzles is higher than the plane strain fracture toughness. Applying the proposed evaluation methodology, it is possible to reflect the relaxation of the constraint effect in the nozzles of the reactor pressure vessel, therefore, the safe operation area on the pressure-temperature limit curve can be prevented from being excessively limited.

• Journal of Navigation and Port Research
• /
• v.43 no.1
• /
• pp.16-22
• /
• 2019

This study proposed estimation methods for weight and center of gravity of small fishing vessels. Weights loaded on small fishing vessels were divided into fixed weights such as crew, fishing gear, and variable weights such as fuel, fresh water, provision, bait, and fish. Based on statistical analyses with weight data of several small fishing vessels, weight, longitudinal center of gravity (LCG), vertical center of gravity (KG) of each item were represented as linear functions of vessel gross tonnage. In addition, weighting factors of variable weights were added on estimation formulas in accordance with vessel loading conditions, e.g. full load departure condition. Estimation methods were verified using actual small fishing vessel data.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05b
• /
• pp.154-159
• /
• 1998

In order to assess the susceptibility of the environmentally assisted cracking(EAC) on SA508 Cl.3 steel in primary water condition, potential step test and slow strain rate test(SSRT) were conducted in a simulated crack tip condition. In this test, anodic dissolution was dominant in the crack tip environments. Proposed simple dissolution model is a modification of Hishida's anodic dissolution model at the plastic zone. One can predict actual crack growth rate with the smooth specimen through this model.

• The Korea Journal of Herbology
• /
• v.26 no.1
• /
• pp.97-101
• /
• 2011

Objectives : The purpose of this research is to identify the actual origin species imported as Aquilaria malaccensis from Indonesia. Methods : After producing the permanent preparat by cutting off the specimen thinly, we observed its characteristics. Results : The imported ones have not interxylary parenchyma, so none is in the genus aquilaria. Since the aliform parenchyma is mostly observed around the vessel pore, they are in the genus gonystylus, and the rest have no aliform parenchyma, so their specimen is unidentified. Conclusion : The imported as A. malaccensis are not in the genus aquilaria, but most of them are in the genus gonystylus and, for the rest, the specimen is unidentified.

• Journal of Auto-vehicle Safety Association
• /
• v.16 no.1
• /
• pp.49-54
• /
• 2024

This paper provides an analysis of the experimental procedures and results to ensure the reliability of the system manufactured for testing the hydrogen permeability of a 175 L compressed hydrogen container for a hydrogen bus. Based on the hydrogen permeability standard of 6 cc/(h·L), it was injected into the permeability test chamber at 10% intervals, and the permeated hydrogen concentration according to the injected amount was measured and compared with the actual amount of hydrogen permeated. As a result of the experiment, the measured value represented 96.34% of the actual permeation amount, which can be used as basic data for the hydrogen bus vessel permeability test system being built in Korea.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.4
• /
• pp.756-763
• /
• 2001

In the process of integrity evaluation for nuclear power plant components, a series of fracture mechanics evaluation on surface cracks in reactor pressure vessel(RPV) must be conducted. These fracture mechanics evaluation are based on stress intensity factor, K. However, under pressurized thermal shock(PTS) conditions, the combination of thermal and mechanical stress by steep temperature gradient and internal pressure causes considerably high tensile stress at the inside of RPV wall. Besides, the internal pressure during the normal operation produces high tensile stress at the RPV wall. As a result, cracks on inner surface of RPVs may experience elastic-plastic behavior which can be explained with J-integral. In such a case, however, J-integral may possibly lose its validity due to constraint effect. In this paper, in order to verify the suitability of J-integral, tow dimensional finite element analyses were applied for various surface cracks. A total of 18 crack geometries were analyzed, and $\Omega$ stresses were obtained by comparing resulting HRR stress distribution with corresponding actual stress distributions. In conclusion, HRR stress fields were found to overestimate the actual crack-tip stress field due to constraint effect.

• Journal of the Korean Institute of Gas
• /
• v.12 no.2
• /
• pp.69-76
• /
• 2008

Three failure cases of CNG composite vessels were reported since after January 2005. The 1st and 2nd accidents were indebted to vessel defect and installation mistake. The 3rd was caused by gas leak at pipe connections. In this paper various aspects were studied based on information of the three failure analysis, which must be improved for better safety of the CNG bus system. Overpressure region caused by vessel explosion was theoretically predicted and also assessed by PHAST program. Explosion of 120 l vessel under 20 MPa is equivalent to 1.2 kg TNT explosion. The predicted value by PHAST was more serious than theoretical one. However, actual consequence of explosion was much less than both of the predicted consequences. Since the CNG vessel was designed by the performance based design methodology, it is difficult to verify whether the required process and tests were properly conducted or not after production. If material toughness is not enough, the vessel should be weak in brittle fracture at early in the morning of winter season since the metal temperature can be lower than the transition temperature. If autofrettage pressure is not correct, fatigue failure due to tensile stress during repeated charging is possible. One positive aspect is that fire did not ocurred after vessel failure. This may be indebted to fast diffusion of natural gas which hindered starting fire.