• Journal of architectural history
• /
• v.24 no.3
• /
• pp.43-56
• /
• 2015

Researches on the pit dwellings in the Joseon Dynasty era have been constantly conducted in the archeology field since the beginning of the 2000s. Most of the related researches in the past have been on the classification and chronological record of dwelling types in archeology, but architectural researches on the dwelling history that is connected from the prehistoric age to the Joseon Dynasty era are insufficient. There are no big differences between the excavated pit dwellings of the Joseon Dynasty era and those of the prehistoric age, so pit dwellings were considered to have been used as dwellings for common people until the Joseon dynasty era. This fact is confirmed by the frequency and density of pit dwellings. In this research, what space composition of the pit dwellings that are equipped with the Korean floor heating system is shown according to the plan types was examined and the development and transition process from pit dwellings to Folk houses were analyzed and their correlations with the Folk houses of the Joseon Dynasty era were examined. The Folk house form did not start with the form of the house on the ground but originate from the introduction of Ondol, the Korean floor heating system, to pit dwellings. As the Korean floor heating system is used, the room and kitchen space are composed in the pit dwelling, and the kitchen is expanded to the one that separates the fireplace for cooking to avoid heating that is unnecessary for the summer season. As the size of the dwelling was getting bigger, the division of the space is made by the pillars that support the interior space. Also, the dwelling is expanded into a single row house and a double row house according to the progress direction of Ondol. In other words, the pit dwellings in the Joseon Dynasty era develops with making up diverse floors through the combination and expansion of Ondol and kitchen according to the dweller's convenience and life style and surrounding environment. This research is significant in the sense that it helps understand the formation and development process of our traditional Folk houses and fills the gap between the pit dwellings, which have been dealt with inadequately, and traditional Folk houses in the Korean dwelling history.

• Journal of the Microelectronics and Packaging Society
• /
• v.16 no.3
• /
• pp.39-43
• /
• 2009

In this paper, the flow characteristics of underfill material driven by capillary action between flip-chip and substrate were investigated. Also, the effects of viscosity level and dispensing point of underfill on flow characteristics were investigated. Flip chip package size was $5mm{\times}5mm{\times}0.65^tmm$, the diameter of solder bump was 100 ${\mu}m$, and the pitch was 150 ${\mu}m$. It was full grid area-array type with 1024 I/Os. The glass substrate was used and the gap between the chip and substrate was 50 ${\mu}m$. For the experimental study, three different underfills with different viscous properties($2000{\sim}3700$ cps), and two different types of dispensing methods(center dot and edge dot) were used. The flow characteristics and filling time of underfill were investigated by using CCD camera. The results show that the edge flow was faster than center flow due to the edge effect, which was caused by the resistance of solder bumps. In case of edge dot dispensing type, the filling time was faster due to the large edge effect, compared to center dot dispensing type. Also, it was found that the underfill flow was faster and the filling time decreased as the viscosity level of underfill was decreased.

• Journal of Wetlands Research
• /
• v.20 no.3
• /
• pp.263-271
• /
• 2018

In this study, we analyzed the removal efficiency of ammonia nitrogen and phosphate dependant on the column depths using various absorbents such as zeolite silica sand, and activated carbon through the column test. In addition, we analyzed electrochemical adsorption behaviors of ammonia nitrogen and phosphate through the quantum mechanical calculation based on density functional theory calculation. Experimental results represent the removal efficiency of ammonia nitrogen and phosphate are zeolite > activated carbon > silica sand, and activated carbon > zeolite > silica sand, respectively. Zeolite shows high adsorption property for ammonia nitrogen over 90%, regardless of the column depth, while activated carbon exhibits high adsorption property for both ammonia nitrogen and phosphate as the column depth for filter media increases. Theoretical findings using DFT calculation for the adsorption behaviors of adsorbents (activated carbon and silica sand) and nutrients ($PO_4{^{3-}}$, $NH_4{^{+}}$) show that activated carbon represented narrower HOMO-LUMO band gap with high adsorption energy, and even more favorable environment for electron adsorption than silica sand, which leads to the effective removal of nutrients.

• Clinics in Orthopedic Surgery
• /
• v.10 no.4
• /
• pp.439-447
• /
• 2018

Background: Since open Wiltse approach allows limited visualization for foraminal stenosis leading to an incomplete decompression, we report the short-term clinical and radiological results of unilateral biportal endoscopic foraminal decompression using $0^{\circ}$ or $30^{\circ}$ endoscopy with better visualization. Methods: We examined 31 patients that underwent surgery for neurological symptoms due to lumbar foraminal stenosis which was refractory to 6 weeks of conservative treatment. All 31 patients underwent unilateral biportal endoscopic far-lateral decompression (UBEFLD). One portal was used for viewing purpose, and the other was for surgical instruments. Unilateral foraminotomy was performed under guidance of $0^{\circ}$ or $30^{\circ}$ endoscopy. Clinical outcomes were analyzed using the modified Macnab criteria, Oswestry disability index, and visual analogue scale. Plain radiographs obtained preoperatively and 1 year postoperatively were compared to analyze the intervertebral angle (IVA), dynamic IVA, percentage of slip, dynamic percentage of slip (gap between the percentage of slip on flexion and extension views), slip angle, disc height index (DHI), and foraminal height index (FHI). Results: The IVA significantly increased from $6.24^{\circ}{\pm}4.27^{\circ}$ to $6.96^{\circ}{\pm}3.58^{\circ}$ at 1 year postoperatively (p = 0.306). The dynamic IVA slightly decreased from $6.27^{\circ}{\pm}3.12^{\circ}$ to $6.04^{\circ}{\pm}2.41^{\circ}$, but the difference was not statistically significant (p = 0.375). The percentage of slip was $3.41%{\pm}5.24%$ preoperatively and $6.01%{\pm}1.43%$ at 1-year follow-up (p = 0.227), showing no significant difference. The preoperative dynamic percentage of slip was $2.90%{\pm}3.37%$; at 1 year postoperatively, it was $3.13%{\pm}4.11%$ (p = 0.720), showing no significant difference. The DHI changed from $34.78%{\pm}9.54%$ preoperatively to $35.05%{\pm}8.83%$ postoperatively, which was not statistically significant (p = 0.837). In addition, the FHI slightly decreased from $55.15%{\pm}9.45%$ preoperatively to $54.56%{\pm}9.86%$ postoperatively, but the results were not statistically significant (p = 0.705). Conclusions: UBEFLD using endoscopy showed a satisfactory clinical outcome after 1-year follow-up and did not induce postoperative segmental spinal instability. It could be a feasible alternative to conventional open decompression or fusion surgery for lumbar foraminal stenosis.

• The Journal of Korean Society for School & Community Health Education
• /
• v.4
• /
• pp.43-59
• /
• 2003

The purpose of this study was to examine whether the gender, grade and school type of middle school students made any differences to their sexual awareness and sexual behaviors in an effort to lay the groundwork for providing more efficient sex education. The research questions were posed as follows: First, what is the sexual awareness of middle school students? Second, what are the sexual behaviors of middle school students? Third, are their gender, school year and school type related to their sexual awareness and behaviors? The subjects in this study were 976 middle school students from Gyeonggi province. After a survey was conducted with questionnaires prepared by this researcher based on earlier studies to suit the purpose of the study, the collected data were analyzed with SPSS 10.0 program. The frequency analysis, x2 test and correlational analysis were implemented, and basic statistical data were obtained. The conclusions were as follows: First, regarding their sexual awareness, the largest group of them agreed that one must report in case of being raped(4.36), and the smallest number of them thought that one might have a sexual relationship with a person other than his or her spouse after marriage(1.56). Second, as for experience of indecent materials, part of sexual behaviors, 67.4 percent had ever contacted such materials. The most common medium through which they contacted them was the Internet(56.5%). The above-mentioned findings suggested that the sexual awareness of the middle school students wasn't influenced by gender or school type. But that varied with grade, as the third graders had the best sexual consciousness. Their sexual behaviors were different according to gender. The boy students contacted more indecent materials, and their experience of such materials varied with grade, since the third graders contacted the most obscene materials. And that also varied with school type, and the non-engineering students contacted more obscene materials. As for sexual drives, their masturbation experience was different according to gender, grade and school type. The number of the boys who practiced masturbation was four-fold larger than that of the girls, and the second graders had more such experience. By school type, the non-engineering students practiced more masturbation, but there was no significant gap between their kissing, caressing and dating experiences.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.6
• /
• pp.962-967
• /
• 2010

The influences of the different mixture of urea fertilizer and pig manure compost as a nitrogen (N) source on Chinese cabbage yield, N uptake, and N agronomic efficiency (AE) were evaluated in two soils having different soil fertility levels. Increasing urea application level was very effective to improve yield and N uptake of Chinese cabbage, and the highest yield was obtained by urea fertilization alone in two soils. On the other hand, the lowest yield and N uptake was obtained from compost alone application in two soils. There was no significant difference in terms of the nitrogen AE between low and high fertility soils that were fully applied with urea. The AE values of Chinese cabbage applied by compost alone were significantly higher in the soil having a low fertility (28.8 g $g^{-1}$) than that in soil with high fertility (16.2 g $g^{-1}$), suggesting that N in compost was more responsive in improving the yield of Chinese cabbage in low fertility soils.

• Convergence Security Journal
• /
• v.18 no.1
• /
• pp.43-60
• /
• 2018

Recently, with the arrival of the 4th industrial revolution, the security risks are converging and complexly changing, and the demand of cybersecurity experts is increasing. Therefore, in this paper, it is the largest of the domestic educational institutions, it has the largest number of emissions talent, and selects the representative major field of humanities and society. Then, after analyzing the common curriculum in each major field, compare it with the training course of cybersecurity experts derived through existing previous research. Through analysis results, we try to design a retraining course for cybersecurity professional human resources. Utilizing the results of this research, it is expected that it will be used as the basic material necessary for the subjects of the re-curriculum education. It is also expected to contribute to resolving the supply-demand gap of cybersecurity professionals.

• Korean Journal of Social Welfare Studies
• /
• v.43 no.2
• /
• pp.141-178
• /
• 2012

Although the rate of self-employment is high in Korean labor market and the rate gap between age groups is high, few studies have addressed on the effects of push factors on transition into self-employment across age groups. The goal of this research is to determine if push factors exert different effects on the self-employment decisions across age groups. There is interest in testing push hypothesis and pull hypothesis. The Korean Labor and Income Panel Study wave 6~11 is used to test this study's hypothesis. The main contribution of the paper is that in case of high unemployment, the probability of transition into self-employment increases. It is consistent with the push hypothesis. Many people are forced to become self-employed person due to the high rate of unemployment and limited occupational choice rather than the role of entrepreneurship. By age subgroup, the transition into self-employment of the ages of 30 and 49 is high. In addition, people at 40-49 years of age are more likely to become self-employed as a response of inadequate job opportunities. It provides the evidence that the self-employment is not a matter of special age group in that people in the 30 to 49 year old age group whose economic activities are vigorous move into marginalized labor market. Furthermore, it seems to be threatened the employment's stability of the prime age in that even people who are age 40-49 years of age are pushed into self-employment because of the recession.

• Korean Journal of Radiology
• /
• v.22 no.5
• /
• pp.706-713
• /
• 2021

Objective: To evaluate the impact of surgical simulation training using a three-dimensional (3D)-printed model of tetralogy of Fallot (TOF) on surgical skill development. Materials and Methods: A life-size congenital heart disease model was printed using a Stratasys Object500 Connex2 printer from preoperative electrocardiography-gated CT scans of a 6-month-old patient with TOF with complex pulmonary stenosis. Eleven cardiothoracic surgeons independently evaluated the suitability of four 3D-printed models using composite Tango 27, 40, 50, and 60 in terms of palpation, resistance, extensibility, gap, cut-through ability, and reusability of. Among these, Tango 27 was selected as the final model. Six attendees (two junior cardiothoracic surgery residents, two senior residents, and two clinical fellows) independently performed simulation surgeries three times each. Surgical proficiency was evaluated by an experienced cardiothoracic surgeon on a 1-10 scale for each of the 10 surgical procedures. The times required for each surgical procedure were also measured. Results: In the simulation surgeries, six surgeons required a median of 34.4 (range 32.5-43.5) and 21.4 (17.9-192.7) minutes to apply the ventricular septal defect (VSD) and right ventricular outflow tract (RVOT) patches, respectively, on their first simulation surgery. These times had significantly reduced to 17.3 (16.2-29.5) and 13.6 (10.3-30.0) minutes, respectively, in the third simulation surgery (p = 0.03 and p = 0.01, respectively). The decreases in the median patch appliance time among the six surgeons were 16.2 (range 13.6-17.7) and 8.0 (1.8-170.3) minutes for the VSD and RVOT patches, respectively. Summing the scores for the 10 procedures showed that the attendees scored an average of 28.58 ± 7.89 points on the first simulation surgery and improved their average score to 67.33 ± 15.10 on the third simulation surgery (p = 0.008). Conclusion: Inexperienced cardiothoracic surgeons improved their performance in terms of surgical proficiency and operation time during the experience of three simulation surgeries using a 3D-printed TOF model using Tango 27 composite.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.1
• /
• pp.625-636
• /
• 2017

Dyslipidemia, hypertension, and diabetes are well-established risk factors for cardio-cerebrovascular disease (CVD). Although the prevalence of dyslipidemia among Korean adults is very high, its management is known to be poor. The aim of this study was to assess the prevalence, awareness, treatment, and control rates of dyslipidemia among adults aged 30 years and older in Gangwon-do, Korea. Analysis included 58,121 adults (29,123 males and 28,998 females) participating in the 2013-2014 Korea National Health Screening Program (KNHSP). Dyslipidemia was defined according to the treatment criteria rather than the diagnostic criteria in Korea. Therefore, high-low-density lipoprotein cholesterol (LDL)-cholesterolemia was deemed present in individuals with LDL-cholesterol levels that exceeded the appropriate risk-based threshold. The age-standardized prevalence was highest in dyslipidemia (32.5%), followed by hypertension (25.1%), and diabetes (9.4%). The awareness rate was 76.7% for hypertension and 74.7% for diabetes, but only 10.6% for dyslipidemia. The lowest patient treatment was found for dyslipidemia (9.4%). The control rate among those undergoing treatment was highest for hypertension (75.8), followed by dyslipidemia (63.3%), and diabetes (43.9%). The higher CVD-risk categories showed lower control rates of hyper-LDL-cholesterolemia. The prevalence of dyslipidemia was higher than hypertension and diabetes, but awareness and treatment rates were lower. Our findings indicate there is a wide gap between the prevalence of dyslipidemia and subsequent treatment, which suggests that effective strategies are required to improve dyslipidemia management. It would be worthwhile to strengthen the follow-up management of patients with dyslipidemia in the KNHSP, especially for the high risk group of CVD.