• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.117-129
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• 2022

The ability to creatively pursue new knowledge and perspectives across various disciplines has established itself as a basic literacy for living in the 21st-century convergence era. With the development of various creative education programs, assessment tools that can objectively and systematically evaluate learners' academic achievement are also required. Therefore, this paper proposed the self assessment, peer assessment, creativity assessment, and reflection tool based on the hyper blended practical model as assessment tools for creative convergence education programs for elementary and secondary school students. The developed assessment tools attempted to develop more completed evaluation methods by modifying two items and deleting four items through validity tests. In addition, the evaluation tool was applied to 596 elementary and secondary school students nationwide, and the application results were analyzed through one-way ANOVA and Wordcloud system. As a result of the analysis, it was found that the self assessment and the reflection tool need to develop questions according to the grade group. In addition, we proposed to use these assessment tools in blended classes or various educational activities in the changing classroom environment. We hope that this paper provides implications for developing evaluation systems and tools for creative convergence education.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.39 no.9
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• pp.41-51
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• 2010

건물의 배수 및 통기시스템에서 나타나는 현상중에 확실한 내용이 아직 밝혀지지 않은 부분이 몇 가지 남아 있다. 이것은 19세기 말엽의 근대 위생공학의 시작 단계에서부터 잘 알려진 사실이다. 건물의 배수 및 통기시스템 운용에 대한 내용은 일반 공학과 특정 유체역학의 범위 내에서 가장 잘 이해할 수 있다. 건물의 배수 및 통기시스템의 운영에 종사했던 초기의 기술진들은 이러한 점을 잘 알고 있었으며 유체역학에 적합하게 응용한 많은 사례를 확인할 수 있었다. 제2차 세계대전이 끝나고 이에 대한 많은 연구가 진행되어 왔으며 특히 유럽에서 시작된 전후 재건 붐을 통해 배수 및 통기시스템의 설계에 좀 더 효율적인 접근이 진척되게 되었다. 이러한 배수시스템의 중심에는 배수관 내부의 오염된 공기가 배수구 또는 위생기구를 통하여 주거 공간으로 유입되는 것을 방지하는 트랩(Water Trap)이 있다. 배수트랩의 주요 기능인 봉수는 일반적으로 깊이가 40 mm에서 50 mm 정도로 위생기구의 종류에 따라 봉수의 깊이는 다소 차이가 있다. 배수관내 공기의 흐름이 중요한 것처럼 트랩의 봉수 메커니즘이 중요하기 때문에 이 메커니즘을 소홀히 여긴다면 안전한 배수시스템의 운영을 기대하기는 어렵다. 배수관 내의 공기의 흐름은 배수에 의해 유입되거나 또는 배출된다. 배수관에서 내부 압력의 불규칙한 변화로 인하여 야기되는 불안정한 배수의 흐름은 트랩의 봉수를 파괴하고 나아가 주거공간으로 오염된 공기가 새어 나갈 수 있는 통로를 제공하게 된다. 관내압력의 천이는 이로 인한 문제가 발생할 가능성이 있는 위치에 그 압력을 완화할 수 있는 장치를 설계단계에 반영하여 적용함으로써 제어할 수 있다. 건물 내부에 상당한 길이의 통기배관을 설치하는 것은 배관의 마찰손실로 인하여 천이 현상을 효과적으로 제어할 수 있는 확실한 방법이 되지는 못한다. 그렇지만 통기밸브를 설치하는 것과 같이 배수관 내로 공기를 공급해주는 유입구를 건물 내부에 분산 설치하는 것이 효율적인 통기방식이 될 수 있고, 정압 천이로 인한 위험을 줄여줄 수 있다. 통기밸브는 정압 발생의 원인이 되지 않으며 단지 정압에 반응하여 더욱 기밀하게 닫히며, 약화된 압력파를 반사할 뿐이다. 고층 건물에서 배수입상관과 평행하게 설치된 통기입상관(Parallel Vent Pipe)의 경우 극히 일부분의 정압 천이 현상을 완화할 수 있다. (통기 배관의 직경이 배수 입상배관과 동일한 경우 대략 1/3 정도임), 그러므로 정압의 천이로 인한 압력 파동은 배수 시스템의 나머지 부분을 통해 전파되어 배수 트랩에 영향을 미치게 된다. 정압의 천이가 예상되는 위치에 정압천이 완화 장치(Positive Air Pressure Transient Alleviation Device)를 사용하면 배관 내부압력의 급격한 상승을 방지하여 연결된 트랩의 봉수를 보호할 수 있다. 이렇게 되면 순간적으로 발생하는 배관내 압력의 급등 현상을 90% 정도까지 완화 시킬 수 있다. 경험적으로 배수시스템에서 배관이 완전하게 막혀 과도한 정압이 발생하는 경우는 거의 없다. 이러한 경우에는 가장 낮은 위치에 있는 배수 트랩의 봉수가 깨지면서 자연스럽게 배수시스템의 압력이 해소되게 된다. 이러한 사례는 통기 방식과 상관없이 발생할 수 있다. 실제와 유사한 시뮬레이션을 통하여 통기 밸브(Air Admittance Valves)는 전면 통기 시스템 (Fully Vented System)에서 최소한 트랩의 봉수 보호용으로 적합한 것이 확인 되었다. 어떤 경우 에는 고층 건물에 더욱 적합하다는 것을 확인할 수 있었다. 부압 해소용으로 통기밸브를 이용하고 정압완화용으로 정압 완화장치(PAPAs: Positive Air Pressure Transient Attenuators)를 사용하는 전면적 능동 제어시스템(Fully Engineered Designed Active Control System)이 사용자에게 육안으로는 확인하지 못하는 기능을 보장하면서 배수 시스템의 안전과 효율성에 대한 효과적인 방법을 제공하고 있다.

• Land and Housing Review
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• v.15 no.1
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• pp.39-55
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• 2024

The aim of this study is to analyse housing satisfaction among residents of different types of public rental housing-permanent, national, and happy housing-following the integration of housing types upon the full-scale supply of integrated public rental housing. By identifying key factors that influence residential satisfaction, our goal is to inform the planning of public rental housing complexes and derive policy implications. The study focuses on analysing discrepancies in residential satisfaction among residents of different types of public rental housing and comparing the factors influencing this satisfaction. Microdata from the Ministry of Land, Infrastructure, and Transport's 'Housing Situation Survey' in 2021 is utilized for analysis, employing one-way ANOVA and binomial logistic regression methods. Empirical analysis reveals variations in residential satisfaction levels between residents of permanent and national rental housing, with national rental housing residents exhibiting higher satisfaction. The influencing factors of overall condition satisfaction are consistent for permanent and national rental residents but differ for happy housing residents. Additionally, the influencing factors of overall residential environmental satisfaction vary across all three housing types. Nonetheless, common factors across all types include housing noise and facility accessibility, highlighting their significance in complex planning. Subsequent studies may involve time series analysis to assess changes in influencing factors over time.

• Journal of Digital Convergence
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• v.22 no.1
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• pp.1-14
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• 2024

In order to improve the effectiveness of carbon neutrality in Jeju Special Self-Governing Province, this study identifies the current state of social environmental education through literature research, excluding school environmental education being implemented in elementary, middle, and high schools in the province, and identifies shortcomings or problems. The purpose is to establish a plan to systematically and integratedly operate social environmental education, and the derived plan can be used as a guide to change environmental awareness and induce eco-friendly behavior to improve the effectiveness of carbon neutrality. As a result of the study, Jeju Special Self-Governing Province established a consultative body with environmental education institutions, organizations and expert groups operating dispersed throughout the province through the substantial operation and support of the environmental education center currently being entrusted, to identify the current status and develop content necessary for establishing environmental education policies, establishing a platform to enable information sharing, role division, regular communication, empathy, and policy feedback, and on-site environmental education centered on the field to stimulate emotions and personalize environmental problems so that environmental problems can be properly recognized. Emphasizing the necessity.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.324-332
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• 2009

The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained cortical bone, trabecular bone, periodontal ligament, 4 mm apical root canal filling, and post-and-core. Six combinations of three parallel type post (zirconia ceramic, glass fiber, and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. A 50 N static occlusal load was applied to the palatal surface of the crown with a $60^{\circ}$angle to the long axis of the tooth. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. An increase of the elastic modulus of the post material increased the stress, but shifted the maximum stress location from the dentin surface to the post material. Buccal side of cervical region (junction of core and crown) of the glass fiber post restored tooth was subjected to the highest stress concentration. Maximum von Mises stress in the remaining radicular tooth structure for low elastic modulus resin core (29.21 MPa) was slightly higher than that for high elastic modulus resin core (29.14 MPa) in case of glass fiber post. Maximum displacement of glass fiber post restored tooth was higher than that of zirconia ceramic or stainless steel post restored tooth.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.161-173
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• 2021

The shipping industry plummeted and was depressed due to the global economic crisis caused by the bankruptcy of Lehman Brothers in the US in 2008. In 2020, the shipping market also suffered from a collapse in the unstable global economic situation due to the COVID-19 pandemic, but unexpectedly, it changed to an upward trend from the end of 2020, and in 2021, it exceeded the market of the boom period of 2008. According to the Clarksons report published in May 2021, the decrease in cargo volume due to the COVID-19 pandemic in 2020 has returned to the pre-corona level by the end of 2020, and the tramper bulk carrier capacity of 103~104% of the Panamax has been in the ports due to congestion. Earnings across the bulker segments have risen to ten-year highs in recent months. In this study, as factors affecting BDI, the capacity and congestion ratio of Cape and Panamax ships on the supply side, iron ore and coal seaborne tonnge on the demand side and Granger causality test, IRF(Impulse Response Function) and FEVD(Forecast Error Variance Decomposition) were performed using VAR model to analyze the impact on BDI by congestion caused by strengthen quarantine at the port due to the COVID-19 pandemic and the loading and discharging operation delay due to the infection of the stevedore, etc and to predict the shipping market after the pandemic. As a result of the Granger causality test of variables and BDI using time series data from January 2016 to July 2021, causality was found in the Fleet and Congestion variables, and as a result of the Impulse Response Function, Congestion variable was found to have significant at both upper and lower limit of the confidence interval. As a result of the Forecast Error Variance Decomposition, Congestion variable showed an explanatory power upto 25% for the change in BDI. If the congestion in ports decreases after With Corona, it is expected that there is down-risk in the shipping market. The COVID-19 pandemic occurred not from economic factors but from an ecological factor by the pandemic is different from the past economic crisis. It is necessary to analyze from a different point of view than the past economic crisis. This study has meaningful to analyze the causality and explanatory power of Congestion factor by pandemic.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.112-121
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• 2004

A study was performed to examine the effects of UV-disinfected reclaimed water on microorganism concentration during rice culture. Four treatments were used and each one was triplicated to evaluate the changes of microorganism concentrations: stream water irrigation (STR), biofilter effluent irrigation (BE), UV-disinfected water irrigation with dose of 6 mW ${\cdot}$ s $cm{-2}$ (UV-6), and UV-disinfected water irrigation with dose of 16 mW ${\cdot}$ s $cm{-2}$ (UV-16). The indicator microorganisms of interest were total coliform (TC), fecal coliform (FC), and E. coli. The biofilter effluent from 16-unit apartment sewage treatment plant was used as reclaimed water and flowthrough type UV-disinfection system was used. Concentrations of indicator microorganisms in the treatment plots ranged from $10^2$ to $10^5$ MPN/100 mL during 24 hours after irrigation in May and June, where initial irrigation water for transplanting reparation was biofilter-effluent without UV-disinfection. It implies that initial irrigation using only non-disinfected reclaimed water for puddling in paddy field can be health-concerned because of more chance of farmer's physical contact with elevated concentration of microorganisms. The concentrations of microorganisms varied widely with rainfall, and treatments using UV-disinfected water irrigation showed significantly lower concentrations than others and their levels were within the range of paddy rice field with normal surface water irrigation. The mean concentrations of STR and BE during growing season were in the range of 4 ${\times}\;10^3$ MPN/100 mL for TC, and 2${\times}\;10^3$ MPN/100 mL for FC and E, Coli, While mean concentrations of UV-S and UV-lS were less than 1${\times}\;10^3$ MPN/100 mL for all the indicator microorganisms. Overall, UV-disinfection was thought to be feasible and practical alternative for agricultural reuse of secondary level effluent in Korea.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.1-7
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• 2001

This paper presents a 'consequence analysis' for vapor cloud explosions caused by heavy gas leakages from commercially used storage tanks at petrochemical plants. Particularly, this paper emphasizes on evaluating the results of various vapor cloud explosion accidents from Butane storage tanks. Also this paper analyses the impact of variables on the accidents in order to acquire the optimum conditions for variables. $SuperChems^{TM}$ Professional Edition was applied to analyse the impact (If atmospheric and other variables in the situation where vapor cloud continuously disperses from the ground level. Under the assumption that practical operating conditions are selected as a standard condition, and Butane leaks from the storage tank for 15 minutes, the results show that the maximum distance of LFL (Lower Flammable Limit) was 52 meters and overpressure by the vapor cloud explosion was 1 psi at 128.2 meters. It is observed that the impact of the variables on accidental Butane storage tank leakage mainly varied upon atmospheric stability, wind velocity, pipe line size, visible length, etc., and changes in the simulation result occurred as the variables varied. The maximum distance of the LFL (Lower Flammable Limit) increased as the visible length became shorter, the size of the leak became larger, the wind velocity was decreased, and the climatic conditions became more stable. Thus, by analysing the variables that influence the simulation results of explosions of Butane storage tanks containing heavy gases, I am presenting the most appropriate method for 'consequence analysis' and the selection of standards for suitable values of variables, to obtain the most optimal conditions for the best results.

• Korean Journal of Psychosomatic Medicine
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• v.20 no.2
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• pp.75-81
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• 2012

Objectives : Thyroid cancer patients may experience emotional distress during cancer treatment including surgical operation and radioactive iodine treatment. The aims of this prospective study were to investigate changes of anxiety and depressive symptoms in patients with differentiated thyroid cancer(DTC) under preoperative, postoperative and short-term hypothyroidism state. Methods : Using the Hospital Anxiety and Depression scale(HAD) and the Distress Thermometer, we sequentially assessed the levels of anxiety, depression and distress in 41 DTC patients at 3 time points such as preoperative state, postoperative state and short-term hypothyroidism state. Results : The HAD-anxiety score was significantly higher in preoperative state($6.93{\pm}3.97$) than postoperative state($4.22{\pm}2.92$) and short-term hypothyroidism state($4.93{\pm}3.64$). Any other significant change in depression or distress thermometer score was not observed. Especially, difference of HADS score between the distress and none-distress groups was significant in preoperative state and post-operative state, but the difference become not significant in the short-term hypothyroidism state. Conclusions : Induced thyroid hormone deficiency during cancer treatment does not significantly affect emotional distress in patient with DTC. Anxiety and depression in these patients may be associated with distress of the patient before active cancer treatment.

• Korean Journal of Heritage: History & Science
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• v.42 no.3
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• pp.66-87
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• 2009

The definition of the structure of wooden chamber tomb(piled stone-type) is as follows. It is a tomb with wooden chamber, and stones were piled on top of the wooden chamber, and then a wooden structure was placed on top of the piled stones, and more stones were piled on top of the wooden structure, and sealed with clay. Of course this definition can vary according to periods, the buried, etc. Gyeongju-style piled stone type wooden chamber tombs have some distinguished characteristics compared to general definition of piled stone type wooden chamber tombs. Outside the wooden chamber, either stone embankments or filled-in stones were layed out, and pilet-in stones are positioned right above the wooden chamber, and almost every class used this type, and finally, it is exclusively found in Gyeongju area. First generations of this Gyeongju-style piled stone type wooden chamber tombs appeared in first half of 5th century. These tombs inherited characteristics like ground plan, wooden chamber, double chamber(inner chamber and outer chamber), piled stones, burial of the living with the dead, piled stones, from precedent wooden chamber tombs. However these tombs have explicit new characteristics which are not found in the precedent wooden chamber tombs such as stone embankments, wooden pillars, piled stones(above ground level), soil tumuluses. stone embankments and wooden pillars are exclusively found on great piled stone type above-ground level wooden chamber tombs such as the Hwangnamdaechong(皇南大塚). Stone embankments, wooden pillars, piled stones(above ground level) are all elements of building process of soil tumuluses. stone embankments support outer wall of above-ground level wooden chambers and disperse the weight of tumuluses. Wooden pillars functioned as auxiliary supports with wooden structures to prevent the collapse of stone embankments. Piled stones are consists of stones of regular size, placed on the wooden structure. And after the piled stones were sealed with clay, tumulus was built with soil. Piled stones are unique characteristics which reflects the environment of Gyeongju area. Piled stone type wooden chamber tombs are located on the vast and plain river basin of Hyeongsan river(兄山江). Which makes vast source of sands and pebbles. Therefore, tumulus of these tombs contains large amount of sands and are prone to collapse if soil tumulus was built directly on the wooden structure. Consequently, to maintain external shape of the tumulus and to prevent collapse of inner structure, piled stones and clay-sealing was made. In this way, they can prevent total collapse of the tombs even if the tumulus was washed away. The soil tumulus is a characteristic which emerges when a nation or political entity reaches certain growing stage. It can be said that after birth of a nation, growing stage follows and social structure will change, and a newly emerged ruling class starts building new tombs, instead of precedent wooden chamber tombs. In this process, soil tumulus was built and the size and structure of the tombs differ according to the ruling class. Ground plan, stone embankments, number of the persons buried alive with the dead, quantity and quality of artifacts reflect social status of the ruling class. In conclusion, Gyeongju-style piled stone type wooden chamber tombs emerged with different characteristics from the precedent wooden chamber tombs when Shilla reached growing stage.