• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.3 s.168
• /
• pp.68-77
• /
• 2005

The set-up of an injection molding process is a ye complicated and time-consuming job because it is required to well determine a lot of variables closely related to products. Thus, the productivity of the set-up process mainly depends on operators' expertise and know-how. To solve the problem mentioned before, this research constructs a support system which helps operators determining the condition of the injection molding easily and systematically. The construction of the support system consists of the following four steps: 1) to determine the control variables which affect the target defect types, 2) to design and implement UI(user interface) using a scenario of set-up process, 3) to design and implement the search algorithms for the initial and optima] condition, and 4) to construct the embedded system which integrates the support system with the operating system of a plastic injection molding machine. The test experiments of some typical products are performed using the embedded system to verify the validity of the support system.

• 대한예방의학회:학술대회논문집
• /
• 1999.10a
• /
• pp.242-243
• /
• 1999

• Journal of Microbiology and Biotechnology
• /
• v.26 no.5
• /
• pp.829-836
• /
• 2016

Penicillin G acylase (PGA) was immobilized on magnetic Fe₃O₄@chitosan nanoparticles through the Schiff base reaction. The immobilization conditions were optimized as follows: enzyme/support 8.8 mg/g, pH 6.0, time 40 min, and temperature 25 ℃. Under these conditions, a high immobilization efficiency of 75% and a protein loading of 6.2 mg/g-support were obtained. Broader working pH and higher thermostability were achieved by the immobilization. In addition, the immobilized PGA retained 75% initial activity after ten cycles. Kinetic parameters V_max and K_m of the free and immobilized PGAs were determined as 0.113 mmol/min/mg-protein and 0.059 mmol/min/mg-protein, and 0.68 mM and 1.19 mM, respectively. Synthesis of amoxicillin with the immobilized PGA was carried out in 40% ethylene glycol at 25 ℃ and a conversion of 72% was obtained. These results showed that the immobilization of PGA onto magnetic chitosan nanoparticles is an efficient and simple way for preparation of stable PGA.

• Smart Structures and Systems
• /
• v.16 no.2
• /
• pp.367-382
• /
• 2015

This paper aims to conduct the reliability-based assessment of the welded joint in the orthotropic steel bridge deck by use of a mesh-insensitive structural stress (MISS) method, which is an effective numerical procedure to determine the reliable stress distribution adjacent to the weld toe. Both the solid element model and the shell element model are first established to investigate the sensitivity of the element size and the element type in calculating the structural stress under different loading scenarios. In order to achieve realistic condition assessment of the welded joint, the probabilistic approach based on the structural reliability theory is adopted to derive the reliability index and the failure probability by taking into account the uncertainties inherent in the material properties and load conditions. The limit state function is formulated in terms of the structural resistance of the material and the load effect which is described by the structural stress obtained by the MISS method. The reliability index is computed by use of the first-order reliability method (FORM), and compared with a target reliability index to facilitate the safety assessment. The results achieved from this study reveal that the calculation of the structural stress using the MISS method is insensitive to the element size and the element type, and the obtained structural stress results serve as a reliable basis for structural reliability analysis.

• Wind and Structures
• /
• v.20 no.2
• /
• pp.315-326
• /
• 2015

To overcome the drawbacks of the traditional contact-type sensor for structural displacement measurement, the vision-based technology with the aid of the digital image processing algorithm has received increasing concerns from the community of structural health monitoring (SHM). The advanced vision-based system has been widely used to measure the structural displacement of civil engineering structures due to its overwhelming merits of non-contact, long-distance, and high-resolution. However, seldom currently-available vision-based systems are capable of realizing the synchronous structural displacement measurement for multiple points on the investigated structure. In this paper, the method for vision-based multi-point structural displacement measurement is presented. A series of moving loading experiments on a scale arch bridge model are carried out to validate the accuracy and reliability of the vision-based system for multi-point structural displacement measurement. The structural displacements of five points on the bridge deck are measured by the vision-based system and compared with those obtained by the linear variable differential transformer (LVDT). The comparative study demonstrates that the vision-based system is deemed to be an effective and reliable means for multi-point structural displacement measurement.

• Human Ecology Research
• /
• v.52 no.5
• /
• pp.519-528
• /
• 2014

This study explores how the main variables of youth going through a transition period (parents' nurturing behavior, the youth's self-esteem and ego resilience, the peer group relationships) affect the youth's school adjustment. It also analyzes the effects of theses variables on the youth's dependence on cell phones, which are considered a necessity in modern society. This research is verified by using a structure model verification method based on data from the Korean Children Youth Panel Study. According to the research, first, 1st-year students in middle school show better adjustment to their school life and less dependence on cell phones when they have a stronger sense of self-esteem and ego resilience; further, it is revealed that cell phone dependence has an indirect influence on the school life of these children. Second, they tend to show better adjustment to their school life and less dependence on cell phones when their parents' nurturing behaviors are more positive. Third, these children tend to depend more on cell phones when they have a positive peer group relationship, Moreover, cell phone dependence has an indirect influence on their school life. When considering the impact of cell phone to youth in modern society, need to prepare proper training program for correct uses and preventing from addiction.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.100-102
• /
• 2002

The demand for a better immobilization device has been increased in the radiation oncology field. Especially, it is essential to have a reliable and practical immobilization tool for the whole body radiosurgery and the IMRT (intensity modulated radiation therapy). A useful method to immobilize the abdomen for the external beam radiation treatment is developed. The air-injected balloon blanket (AIBB) was designed as an immobilization device. As the air was injected into it, it pressed down the patient's abdomen and fixed the patient. The AIBB played a role not only to grab the patients' motion, but also to increase the patients' setup reproducibility. Patients' movements due to the respiration were reduced and the reconstruction could be maximized. The experimental results revealed that the AIBB could be used for the clinic.

• Smart Structures and Systems
• /
• v.20 no.2
• /
• pp.219-229
• /
• 2017

Outlier detection is an imperative task to identify the occurrence of abnormal events before the structures are suffered from sudden failure during their service lives. This paper proposes a two-phase method for the outlier detection of Global Positioning System (GPS) monitoring data. Prompt judgment of the occurrence of abnormal data is firstly carried out by use of the relational analysis as the relationship among the data obtained from the adjacent locations following a certain rule. Then, a negative selection algorithm (NSA) is adopted for further accurate localization of the abnormal data. To reduce the computation cost in the NSA, an improved scheme by integrating the adjustable radius into the training stage is designed and implemented. Numerical simulations and experimental verifications demonstrate that the proposed method is encouraging compared with the original method in the aspects of efficiency and reliability. This method is only based on the monitoring data without the requirement of the engineer expertise on the structural operational characteristics, which can be easily embedded in a software system for the continuous and reliable monitoring of civil infrastructure.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.15
• /
• pp.6075-6080
• /
• 2014

Lung cancer is the leading cause of cancer-related death worldwide. Here we investigated the antitumor effect and mechanism of Zhejiang (Huzhou and Jiande) saffron against lung cancer cell lines, A549 and H446. Using high performance liquid chromatography (HPLC), the contents of crocin I and II were determined. In vitro, MTT assay and annexin-V FITC/PI staining showed cell proliferation activity and apoptosis to be changed in a dose- and time-dependent manner. The inhibition effect of Jiande saffron was the strongest. In vivo, when mice were orally administered saffron extracts at dose of 100mg/kg/d for 28 days, xenograft tumor size was reduced, and ELISA and Western blotting analysis of caspase-3, -8 and -9 exhibited stronger expression and activity than in the control. In summary, saffron from Zhejiang has significant antitumor effects in vitro and in vivo through caspase-8-caspase-9-caspase-3 mediated cell apoptosis. It thus appears to have more potential as a therapeutic agent.

• Korean Journal of Child Studies
• /
• v.10 no.2
• /
• pp.1-18
• /
• 1989

This documentary study explored the stages of human development and education in the Choson Dynasty with the use of "Non Eu, Ye Gi, So Hak, Tae Gyo Sin Gi, and Dong Yi Bo Gam. The findings were compared with Western writings of a comparable period. It was found that education in the Choson Dynasty was largely concerned with mental attitude and conduct in ordinary life (education for manners and living). Education claimed to stand for unity of knowledge and behavior. It was founded on a Confucian view of education with a saint as the ideal model to be emulated. In the early years, home influence was emphasized. This was later replaced by institutional education. Additional education frequently extended to ten years and even forty or more years for the development of leaders. Based on the above findings. It was concluded that (1) the Western stages of human development exemplified by the Puritans and by Rousseau were concerned only with progressive changes from the postnatal stage to adolescence but the stages or the Choson Dynasty applied to the entire life span, from prenatal life through old age: (2) the developmental stages of males and females were defined differently as a result of differences in educational contents and sex-role distinctions: (3) life span educational objectives were Confucian and the preparatory stages were long coming to fruition in late senescence: and (4) although education was centered on manners and based on Confucianism, much of human development in the Choson Dynasty corresponds to that of modern times.