• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.17 no.2
• /
• pp.119-125
• /
• 2021

Subsea pipelines are widely used to transport hydrocarbons from ultra-deep seawater to facilities on the coast. A sandwich pipe is a pipe-in-pipe system in which the annulus between the two concentric steel pipes is filled with polymer cores and fillers for insulation and structural reinforcement. Sandwich pipeline is always exposed to complex loading such as bending moment, bulking, internal and external pressures caused by installation, operation and environmental factors. This research provides insights into the structural integrity of sandwich pipeline exposed to complex loading conditions using a linear matching method (LMM). The finite element model of the sandwich pipeline has been generated from previous research, and the model validation is performed by comparing the results of the linear analysis between the two models. The temperature dependent material properties are used to simulate the behavior of real pipeline, and the elastic-perfectly plastic (EPP) model has been taken into account for the material non-linearity. Numerical results provide comprehensive insights into the structural response of the sandwich pipeline under monotonic and cyclic loading and provide notable points about the evaluation of the plastic collapse limit and the elastic shakedown limit of the sandwich pipeline.

• Applied Chemistry for Engineering
• /
• v.34 no.6
• /
• pp.633-639
• /
• 2023

We synthesized 2-(10-methyl-10H-phenothiazin-3-yl)-5-phenyl-1,3,4-oxadiazole (MPPO) and 5,5-(10-methyl-10H-phenothiazin-3,7-diyl)-bis-(2-phenyl-1,3,4-oxadiazole) (DPPO). MPPO has both electron-donating and electron-accepting substituents with asymmetric molecular geometry. By incorporating one extra electron-accepting group into MPPO, we created a symmetric molecule, which is DPPO. The optical and electrochemical properties of these compounds were measured. The lowest unoccupied molecular orbital (LUMO) level of DPPO was lower than that of MPPO. The excited-state dipole moment of DPPO, with symmetric geometry, was calculated to be 4.1 Debye, whereas MPPO, with asymmetric geometry, had a value of 7.0 Debye. The charge-carrier mobility of both compounds was similar. We fabricated non-doped organic light-emitting diodes (OLEDs) using D-A type molecules as an emitting layer. The current efficiency of the DPPO-based device was 7.8 cd/A, and the external quantum efficiency was 2.4% at 100 cd/m², demonstrating significantly improved performance compared to the MPPO-based device. The photophysical and electroluminescence (EL) characteristics of the two D-A type molecules showed that molecular symmetry, as well as the lowered LUMO level of DPPO, played critical roles in the enhancement of EL performance.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.11 no.1
• /
• pp.141-152
• /
• 2007

Considering uncertainties of random input data, it is more reasonable to use probabilistic method than the conventional deterministic method for the design of structures or for the assessment of the responses of structures, which are designed as safe even under extreme loads. Therefore, to assess the quantitative effects of the constructed cable stayed bridge by the input random variables, a sensitivity analysis is studied. Using perturbation method, an analysis program is developed for the iterative probabilistic finite element analyses and sensitivity analyses of the cable stayed bridge, except the initial shape analysis. Monte-Carlo Simulations were used for the verification of the developed program. The results of sensitivity analysis shows the governing effects of external loads. Because the results also provide the sensitive effects of the stiffness of members and the magnitudes of prestressing force of cables, the developed

• Journal of Gifted/Talented Education
• /
• v.21 no.1
• /
• pp.57-81
• /
• 2011

The purpose of this study was to explore the quality of life of musically talented students as measured by their external experiences (e.g., activities, companions) and internal experiences (e.g., flow, emotion). The participants in this study were 33 musically talented students (10 males, 23 females) aged 13 to 19. Study data were collected for 7 consecutive days using the Experience Sampling Method (ESM), which employs a cellular-phone as a signaling device. The results were as follows: First, in response to the 1625 random signals, musically talented students reported that 40.9% of their time was spent on productive activities. An additional 33.4% of time was used for maintenance activities and the rest of their time was spent on leisure/social activities. Also, musically talented students reported that 48.5% of their time was spent alone. When they were alone, they spent a lot of time engaging in productive activities (44.3%). Second, in order to measure the flow of their life, two methods were used. One used a 4-channel flow model (i.e. apathy, boredom, flow, anxiety) and the other used 8 dimensions and conditions of the flow experience (i.e. concentration, self-consciousness disappears, action and awareness merge, distorted sense of time, freedom from worry about failure, clear goals, immediate feedback, balance between challenges and skills). According to the former, when engaged in music-related activities, musically talented students usually reported flow (54.0%), while they felt apathy (41.3%) for daily routines activities. According to the latter method, musically talented students experienced flow for most productive activities, while they experienced flow least for maintenance activities. Emotional variables of ESF are comprised of 10 semantic scales (i.e. happy-sad, strong-weak, active-passive, sociablelonely, proud-ashamed, involved-detached, excited-bored, clear-confused, relaxed-worried, cooperative-competitive). Musically talented students reported experiencing the most positive emotion for social activities and experiencing the most negative emotion for maintenance activities. Results of this study assert that musically talented students had to trade off immediate enjoyment for developing their special gifts. They could not afford as much time for socializing with friends, and they had to spend more time alone compared to their peers without such gifts. Consequently, they were found to deprive themselves of the spontaneous good times that teenagers usually thrive on. They were helped in this respect by their autotelic personality traits, especially their strong need for achievement and endurance. The downside, however, is that the moment-to-moment quality of their moods suffered. The argument concerning musically talented students applies for all adolescents. The choices that talented students must make between immediate gratification and long-term development, and between solitude and companionship, are the same choices every young person must make, regardless of her or his level of talent. All of us have gifts that are potentially useful and worthy of being appreciated. But to develop these latent talents we must cultivate them, and this takes time and the investment of mental energy. The lifestyle that musically talented students develop can show us some of the choices all of us must make in order to cultivate our gifts.

• Journal of the Microelectronics and Packaging Society
• /
• v.25 no.1
• /
• pp.1-10
• /
• 2018

Recently, there has been rapid development in the field of flexible electronic devices, such as organic light emitting diodes (OLEDs), organic solar cells and flexible sensors. Encapsulation process is added to protect the flexible electronic devices from exposure to oxygen and moisture in the air. Using numerical simulation, we investigated the effects of the encapsulation layer on mechanical stability of the silicon chip, especially the fracture performance of center crack in multi-layer package for various loading condition. The multi-layer package is categorized in two type - a wide chip model in which the chip has a large width and encapsulation layer covers only the chip, and a narrow chip model in which the chip covers both the substrate and the chip with smaller width than the substrate. In the wide chip model where the external load acts directly on the chip, the encapsulation layer with high stiffness enhanced the crack resistance of the film chip as the thickness of the encapsulation layer increased regardless of loading conditions. In contrast, the encapsulation layer with high stiffness reduced the crack resistance of the film chip in the narrow chip model for the case of external tensile strain loading. This is because the external load is transferred to the chip through the encapsulation layer and the small load acts on the chip for the weak encapsulation layer in the narrow chip model. When the bending moment acts on the narrow model, thin encapsulation layer and thick encapsulation layer show the opposite results since the neutral axis is moving toward the chip with a crack and load acting on chip decreases consequently as the thickness of encapsulation layer increases. The present study is expected to provide practical design guidance to enhance the durability and fracture performance of the silicon chip in the multilayer package with encapsulation layer.

• The Journal of Internal Korean Medicine
• /
• v.15 no.1
• /
• pp.152-164
• /
• 1994

In Nai-Gyung(內經), it is said that In-Yeong(人迎) means In- Yeong Maek(人迎脈), Gi-Gu m- eans Tson-Gu(寸口) or Maek- Gu(脈口), In-yeong, artery in the side of neck, is located before Yeong-Geun(瓔筋), called as Jok-Yang-Myung-Maek(足陽明脈),so the part of In-Yeong-Maek means In-Yeong-Hyul(人迎穴) of Jok-Yang-Myung- Wi-Gyung(足陽明胃經) showing the artery in the side of neck. The part of Tson-Gu-Maek is that of artery in Yo-Gol(橈骨), beating source of Soo-Tae-Eum-Maek (手太陰脈) Of In-Yeong-Gi-Gu-Maek, In-Yeong-Maek mainly consists of Yang(陽), Gi-Gu-Maek of Eum(陰), so In-Yeung means physical disease, short of extra Eum component. They said that if In-Yeong-Maek was more than Gi-Gu-Maek, it meant physical injury, while Gi-Gu-Maek was more than In- Yeo-ng-Maek, it meant internal injury. In-Yeong-Gi-Gu-Maek is the one to distinguish the external and internal, the inside and outside, Eum and Yang, but there is no definite classification method to distinguish it, also it is difficult to grasp the comparison of 1sung(1盛), 2sung(2盛), 3sung(3盛), interrelation with 12-Gyung-Rak(l2經絡), change of maek phases, so necessary to set up the clear definition for In-Yeong-Gi-Gu-Maek. For the two theories as to In-Yeong-Gi-Gu-Maek according to Nai-Gyung, the one is to diagnose the maek by comparing the In-Yeong-Hyul with Tson-Gu of Soo-Tae-Eum-Maek as Gi-Gu in the both sides of neck part, he other is to divide the left and right of Gi-Gu-Maek in to In-Yeong and Gi-Gu afterwards, but today it is difficult to compare and explain the medical theory afterwards owing to insufficient consideration of In-Yeong-Gi-Gu-Maek at Nai-Gyung. The diagnosis of In-Yeong-Gi-Gu-Maek at Nai-Gyung to distinguish the surplus and shortage of Eum and Yang up to now since Nai-Gyung has so important and diagnostic value as to grasp the exact meaning. Herewith, this researcher com-pared Nai-Gyung and medical theory afterwards, reported it to consider the fixed position and changing process of viscera and entrails arrangement of literatures introducing In-Yeong-Gi-Gu-Maek, examining the change of maek phases for normal maek and a-bnormal maek of In-Yeong-Gi-Gu-Maek, considering the 1 sung, 2 sung, 3 sung maek phases in In-Yeong-Gi- Gu-Maek. According to the above results, the conclusion was reached as follows. 1. In-Yeong as the outside indicates external disease(外感), showing the surplus and shortage of Yang symptom by having Boo-Maek(浮脈) as Py-ung-Maek(平脈), Gi-Gu as the inside indicates internal disease(內傷), showing the surplus and shortage of Eum symptom by having Chim-Maek(沈脈) as P-yung-Maek(平脈). 2. In Pyung-Maek of In- Yeong-Maek as Boo-Maek, g-radual sinking of more floated changing maek because of disease means the improvement of di-sease, in Pyung-Maek of Gi- Gu-Maek as Chim- Maek, gradual floating of more sunken changing maek because of disease means the improvement of disease. 3. They said that disease of Jok-Gyung-Rak(足經絡) is cha-nged to that of Soo-Kyung-Rak(手經絡) when Jo-Maek(躁脈) appears whether In-Yeong-Maek or Gi-Gu-Maek 4. With the exemples of 1 sung 2 sung 3 sung it was porned with the relation of Pyo-Ri-Soo-Jok(表裏手足). Therfore I can guess that this fact is a moment explained the Bu-You-Sa-Kyung(部有四經) mentioned in Nan-Gyung-18-Nan(難經 第18難). 5. I think that In-Yeong and Gi-Gu, as a diagnosis method which distinguish between the inside indicates internal disease and the outside indicates external disease, is required to study further researches.

• The Journal of the Korea Contents Association
• /
• v.17 no.3
• /
• pp.1-14
• /
• 2017

This study aims to understand the influences that emotional and behavioral problems, relationships with parents, peer groups and teachers have on school refusal tendency and their routes targeting for 546 students of the 1st and 2nd grades in the boys' and girls' middle schools in G city and to conduct a path analysis by using Pearson's product-moment correlation and LISREL program. The results are the followings: First, significant correlation is shown in the all relationships, excluding the external problems out of emotional and behavioral problems, social support factor out of teachers-related variables, negative support factor out of parents-related variables. Second, emotional and behavioral problems have highly direct influence on school refusal tendency and relationship with parents without any meditator effect and has indirect influence on relationships with peer groups and teachers without having statistically significant and direct influence. Also, relationship with peer groups has statistically significant and negative effect on school refusal tendency without having statistically significant and direct influence, teachers relationship has statistically significant and direct effect on school refusal tendency and relationship with parents has indirect influence on school refusal tendency through relationship with peer groups and teachers relationship without having statistically significant and direct effect.

• Korean journal of communication and information
• /
• v.76
• /
• pp.183-219
• /
• 2016

In light of the recent increase in new independent spaces within the field of artistic production, this study seeks to examine the daily experience and art practice of agents in such spaces. In-depth interviews were conducted with fifteen emerging artists, who manage new independent art spaces and participate actively in related activities, and the significance of their activities was analyzed. An important theoretical foundation of this study is Bourdieu's concept of the field of cultural production. According to Bourdieu, in order to understand a specific field, the habitus of agents must be studied together with the structure of the field. This study found that individuals belonging to the same or a close generation exhibit similar attitudes to life based on shared experiences, and they can be connected to their art practice. Most agents of new spaces did not have high expectations for success, and chose to practice art independently while bonding with their peers and enjoying the moment rather than wait for recognition or funding from external sources. Their self-fulfilling habitus is condition-specific and can be regarded as a form of flexible art practice. Given the poor conditions of today's field of artistic production, this is likely to serve as an advantage in entering the field and in position-taking. The social significance of this study lies in the fact that the aforementioned characteristics of the agents of independent production spaces not only reflect the current field of artistic production but also other fields of cultural production at large in our society.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.2 no.2
• /
• pp.77-81
• /
• 2003

Purpose: The biomechanics and kinematics of knee joint were reviewed in this article. And then the common sports injuries were presented. Anatomy and Kinetics: None of the pairs of bearing surfaces in the knee joint is exactly congruent This allows the knee six degrees of freedom of motion. Tibiofemoral Kinematics: In flexion and extension, the axis of motion is not perpendicular to the medial-lateral plane of the joint, nor is it perpendicular to the axis of longitudinal rotation. This results in coupled varus angulation and internal rotation with flexion and in valgus angulation and external rotation with extension. Patellofemoral Articulation: Loads across the patellofemoral joint are indirectly related to the angle of knee flexion and directly related to the force generated within the quadriceps mechanism. Fractures of the Patella: Nonoperative treatment is indicated if the extensor mechanism is intact and if displacement of fragment is minimal. The specific type of internal fixation depends on the fracture pattern. It is important to repair retinaculum. Acute and Recurrent Patellar Instability: The degree of dysplasia and the extent of the instability play a large part in determining the success of nonoperative treatment. Patients who experience recurrent dislocations and patients with major anatomic variations require surgery to minimize their instability. Sports Injuries in School-age Atheletes: Patellar pain in young athletes groups a number of conditions, including Idiopathic Adolescent Anterior Knee Pain, Osgood- Schlatter Disease, and Sinding-Larsen-Johansson Disease.

• Journal of Korean Society of Steel Construction
• /
• v.23 no.6
• /
• pp.669-677
• /
• 2011

The multi-span suspension bridge generally has more than three towers and two main spans. To economically and effectively design a multi-span suspension bridge, the proper stiffness ratio of the center tower to the side tower must be determined. This study was conducted to propose a method of figuring out briefly the structural behavior of the towers in a multi-span suspension bridge. In the equivalent suspension bridge model, the main cable of the multi-span suspension bridge is idealized as an equivalent cable spring, and the external loads of horizontal and vertical forces that were calculated using the tensile forces of the main cable were applied on top of the towers. The equilibrium equations of the equivalent multi-span suspension bridge model were derived and the equations were solved via nonlinear analysis. To verify the proposed method, a sample four-span suspension bridge with a main span length of 3,000 m was analyzed using thefinite element method. The displacements and moment reactions of each tower in the proposed method were compared with the FEM analysis results. Consequently, the results of the analysis of the equivalent suspension bridge model tended to be consistent with the results of the FEM analysis.