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Analysis of Indicator Microorganism Concentration in the Rice Cultural Plot after Reclaimed Water Irrigation (하수처리수 관개후 벼재배 시험구에서 지표미생물 거동 분석)

  • Jung, Kwang-Wook;Jeon, Ji-Hong;Ham, Jong-Hwa;Yoon, Chun-Gyeong
    • 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.

The Survey of Dentists: Updated Knowledge about Basic Life support and Experiences of Dental Emergency in Korea

  • Cho, Kyoung-Ah;Kim, Hyuk;Lee, Brian Seonghwa;Kwon, Woon-Yong;Kim, Mi-Seon;Seo, Kwang-Suk;Kim, Hyun-Jeong
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.14 no.1
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    • pp.17-27
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    • 2014
  • Background: Various medical emergency situations can occur during dental practices. Cardiac arrest is known to comprise approximately 1% of emergency situation. Thus, it is necessary for dentists to be able to perform cardiopulmonary resuscitation (CPR) to increase the chance of saving patient's life in emergency situation. In this paper, we conducted a survey study to evaluate to what extent dentists actually understood CPR practice and if they had experience in handling emergency situations in practice. Method: The survey was done for members of the Korean Dental Society of Anesthesiology (KDSA), who had great interest in CPR and for whom survey-by-mail was convenient. We had selected 472 members of the KDSA with a dental license and whose office address and contact information were appropriate, and sent them a survey questionnaire by mail asking about the degree of their CPR understanding and if they had experience of handling emergency questions before. Statistical analyses -frequency analysis, chi-square test, ANOVA, and so on- were performed by use of IBM SPSS Statistics 19 for each question. Result: Among 472 people, 181 responded (38.4% response rate). Among the respondents were 134 male and 47 female dentists. Their average age was $40.4{\pm}8.4$. In terms of practice type, there were 123 private practitioners (68.0%), 20 professors (11.0%), 16 dentists-in-service (8.8%), 13 residents (specialist training) (7.2%) and 9 military doctors (5%). There were 125 dentists (69.1%) who were specialists or receiving training to be specialist, most of whom were oral surgeon (57, 31.5%) and pediatric dentists (56, 30.9%). There were 153 people (85.0%) who received CPR training before, and 65 of them (35.9%) were receiving regular training. When asked about the ratio of chest pressure vs mouth-to-mouth respiration when conducting CPR, 107 people (59.1%) answered 30:2. However, only 27.1% of them answered correctly for a question regarding CPR stages, C(Circulation)- A(Airway)- B(Breathing)- D(Defibrillation), which was defined in revised 2010 CPR practice guideline. Dentists who had experience of handling emergency situations in their practice were 119 (65.6%). The kinds of emergency situations they experienced were syncope (68, 37.6%), allergic reactions to local anesthetic (44, 24.3%), hyperventilation (43, 23.8%), seizure (25, 13.8%), hypoglycemia (15, 8.3%), breathing difficulty (14, 7.8%), cardiac arrest (11, 6.1%), airway obstruction (6, 3.3%), intake of foreign material and angina pectoris (4, 2.2%), in order of frequency. Most respondents answered that they handled the situation appropriately under the given emergency situation. In terms of emergency equipment they had blood pressure device (70.2%), pulse oximetry (69.6%), Bag-Valve-Mask (56.9%), emergency medicine (41.4%), intubation kit (29.8%), automated external defibrillator (23.2%), suction kit (19.3%) and 12 people (6.6%) did not have any equipment. In terms of confidence in handling emergency situation, with 1-10 point scale, their response was $4.86{\pm}2.41$ points. The average point of those who received regular training was $5.92{\pm}2.20$, while those who did not was $4.29{\pm}2.29$ points (P<0.001) Conclusion: The result showed they had good knowledge of CPR but the information they had was not up-to-date. Also, they were frequently exposed to the risk of emergency situation during their dental practice but the level of confidence in handling the emergency situation was intermediate. Therefore, regular training of CPR to prepare them for handling emergency situation is deemed necessary.

Effects of Horseshoe Expander (Horseshoe Expander의 확장 효과에 관한 연구)

  • Chung, Kyu-Rhim;Park, Young-Guk;Lee, Young-Jun;Kim, Hong-Suk
    • The korean journal of orthodontics
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    • v.30 no.5 s.82
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    • pp.553-563
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    • 2000
  • Horseshoe Expander is one of Slow Maxillary Expansion(SME) which aims to accommodate the contra- lateral expansion and midpalatal suture expansion or the palate. The appliance consists of skeleton type strew embedded in split Horseshoe appliance. It is the objectives of the presentation to manifest the changes in dental & craniofacial components subsequent to the application of Horseshoe Expander. The subjects for this study consisted of 32 patients (mean age : 12.7). frontal, lateral cephalometric headfilm were taken and study casts were fabricated before and after expansion. 24 items were measured, compared preexpansion with postexpansion. Especially, palatal volume was measured by means of 'Hydro-measurement method'. Tooth axis measurement on the dental casts were made with Universal bevel protractor, and Horseshoe Expander group were compared with RME group. This study of changes to maxillary expansion with Horseshoe Expander revealed the following significant results. 1. Triangular-shaped expansion pattern appeared in frontal cephalometric headfilm. 2. Palatal plane, occlusal plane, mandibular plane and upper incisor to FH increased in lateral cephalometrir headfilm. 3. Palatal volume increased significantly. A slight bite opening, reduction of occlusal contact points showed in dental casts. 4. A 2.2:1 ratio of the amount of intermolar width in maxilla(orthodontic movement) to maxillary width (orthopedic movement) was determined. 5. Horseshoe Expander group has less buccal tipping tendency than RME group, by taking high correlation coefficients in the upper second premolar and first molar. It was suggested that Horseshoe Expander showed less orthodontic changes, less buccal tipping tendency. In addition, it was effective in maxillary expansion.

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Improved Photoelectric Conversion Efficiency of Perovskite Solar Cells with TiO2:TiCl4 Electron Transfer Layer (TiO2:TiCl4 전자수송층을 도입한 페로브스카이트 태양전지의 광전변환효율 향상)

  • Ahn, Joon-sub;Kang, Seung-gu;Song, Jae-gwan;Kim, Jin-bong;Han, Eun-mi
    • Journal of the Microelectronics and Packaging Society
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    • v.24 no.4
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    • pp.85-90
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    • 2017
  • The $TiCl_4$ as a blocking material is adsorbed in the mesoporous $TiO_2$ electron transfer layer(ETL) of the Perovskite solar cell to prevent the direct contact between the FTO electrode and the photoactive layer(AL), and facilitate the movement of the electrons between $TiO_2:TiCl_4$ ETL and Perovskite AL to improve the photoelectric conversion efficiency(PCE). The structure of the perovskite solar cell is FTO/$TiO_2:TiCl_4$/Perovskite($CH_3NH_3PbI_3$)/spiro-OMeTAD/Ag. It was investigated that the dipping time of the $TiO_2$ into $TiCl_4$ aqueous solution affects on the photoelectric characteristics of the device. By the dipping for 30 minutes, the PCE of the perovskite solar cell with the $TiO_2:TiCl_4$ ETL was the highest 10.46%, which is 27% higher than the cell with $TiO_2$ ETL. From SEM, EDS, and XRD characterization on the $TiO_2:TiCl_4$ ETL and the perovskite AL, it was measured that the decrease of the porosity of the $TiO_2$ layer, the detection of the Cl component by the $TiCl_4$ adsorption, the cube-type morphology of perovskite AL, and shift of the $PbI_2$ peak of the perovskite AL. From these results, it was confirmed that the $TiO_2:TiCl_4$ ETL and the perovskite AL were formed.

ELECTRON MICROSCOPIC STUDY OF SLOWLY ADAPTING PERIODONTAL MECHANORECEPTIVE PRIMARY AFFERENT FIBERS WITHIN THE SUBNUCLEUS ORALIS OF THE CAT (서순응형 치근막 일차구심성 신경섬유 종말부의 Subnucleus oralis에서의 시냅스 양상에 관한 전자현미경적 연구)

  • Kim, Moo-Jung;Bae, Yong-Chul;Kim, Chin-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.15 no.4
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    • pp.281-301
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    • 1993
  • It was revealed that the morphology and projection pattern of terminal arbors from single primary afferent are different among distinct fiber types, functional types and the different subdivision of trigeminal sensory nucleus complex(TSNC). But it was not identified the ultrastructural morphology and synaptic connections of terminal arbors from each primary afferent within TSNC. So we employed the intra-axonal horseradish peroxidase(HRP) injection technique to define the terminal arbors of primary afferent fiber from slowly adapting mechanoreceptors in the periodontal ligament of the cat, and examined 66 labeled terminal arbors within the rostrodorsomedial part(Vo.r) of the trigeminal nucleus oralis, electromicroscopically with 90nm serial sections. All the boutons labelled with HRP contained clear, spherical and uniform sized synaptic vesicles(diameter : $47.66{\pm}3.58nm$ ). Most of the labelled boutons were boutons en passant type and they were connected by unmyelinated axonal strand. In which neurofilament and microtubule was not developed but occasionally contained synaptic vesicle in contrast to the myelinated axon. The size of the labelled bouton was relatively small(long diameter : $1.46{\pm}0.24{\mu}m$, short diameter $0.85{\pm}0.26{\mu}m$, average diameter $1.15{\pm}0.24{\mu}m$) and the shape of which varied from dome to elongated shape, but scalloped glomerulus shape was not developed. Each primary ending in Vo.r made synapse with one or two neuronal propiles(average : $1.11{\pm}0.31$), of which, 89.4% of labelled boutons made synapse with only one neuronal pro pile, the remainder, 10.6% of labelled boutons, made synapse with two neuronal propile. So characteristically they made very simple synapse. Most of labelled boutons(80.03%) made asymmetrical synapse only with dendritic shaft or spine, and 6.1% of labelled boutons received symmetrical synapse from pleomorphic vesicle containing axonal ending(p-ending). So presynaptic inhibiton was relatively scarce. Synaptic triad, in which a p-ending is presynaptic both pre-and post-synaptic element of the axo-dendritic contact from the labelled primary ending was not observed.

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Accuracy evaluation of microwave water surface current meter for measurement angles in middle flow condition (전자파표면유속계의 측정 각도에 따른 평수기 유속 측정 정확도 분석)

  • Son, Geunsoo;Kim, Dongsu;Kim, Kyungdong;Kim, Jongmin
    • Journal of Korea Water Resources Association
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    • v.53 no.1
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    • pp.15-27
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    • 2020
  • Streamflow discharge as a fundamental riverine quantity plays a crucial role in water resources management, thereby requiring accurate in-situ measurement. Recent advances in instrumentations for the streamflow discharge measurement has complemented or substituted classical devices and methods. Among various potential methods, surface current meter using microwave has increasingly begun to be applied not only for flood but also normal flow discharge measurement, remotely and safely enabling practitioners to measure flow velocity postulating indirect contact. With minimized field preparedness, this method facilitated and eased flood discharge measurement in the difficult in-situ conditions such as extreme flood in active ways emitting 24.125 GHz microwave without relying on natural lights. In South Korea, a rectangular shaped instrument named with Microwave Water Surface Current Meter (MWSCM) has been developed and commercially released around 2010, in which domestic agencies charging on streamflow observation shed lights on this approach regarding it as a potential substitute. Considering this brand-new device highlighted for efficient flow measurement, however, there has been few noticeable efforts in systematic and comprehensive evaluation of its performance in various measurement and riverine conditions that lead to lack in imminent and widely spreading usages in practices. This study attempted to evaluate the MWSCM in terms of instrumen's monitoring configuration particularly regarding tilt and yaw angle. In the middle of pointing the measurement spot in a given cross-section, the observation campaign inevitably poses accuracy issues related with different tilt and yaw angles of the instrument, which can be a conventionally major source of errors for this type of instrument. Focusing on the perspective of instrument configuration, the instrument was tested in a controlled outdoor river channel located in KICT River Experiment Center with a fixed flow condition of around 1 m/s flow speed with steady flow supply, 6 m of channel width, and less than 1 m of shallow flow depth, where the detailed velocity measurements with SonTek micro-ADV was used for validation. As results, less than 15 degree in tilting angle generated much higher deviation, and higher yawing angle proportionally increased coefficient of variance. Yaw angles affected accuracy in terms of measurement area.

A Comparison of the Characteristics of Maritally Violent Men in a Community Sample and Batterers in the Criminal Justice System (지역사회의 폭력남편과 가정폭력범죄 행위자들의 특성 비교)

  • Chang, Hee-Suk
    • Korean Journal of Social Welfare
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    • v.58 no.4
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    • pp.141-168
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    • 2006
  • The present study explored and compared the risk factors of two subtypes of maritally violent men with those of a nonviolent comparison group. One type of batterers consisted of a community sample, and the other was sought from the criminal justice system. The identities of the male community batterers were not exposed to the society since their victims did not contact any of the social service agents related to domestic violence. To identify the different characteristics associated with two subtypes of woman abusers, a total of 152 nonviolent men, 82 male community batterers, and 336 offenders in a criminal justice system were considered. The results of the descriptive analysis showed that the level of physical violence of the community batterers was two times lower than that of the batterers who received legal punishments. The results of the multinominal logistic regression were as follows: (1) The variables that distinguished the male community batterers from the nonviolent men were the use of physical violence towards children, marital decision power, and income. (2) Four factors had been found to distinguish batterers in the criminal justice system from nonbatterers, namely: attitudes towards woman battering, education, violence towards children, and level of jealousy. (3) The community batterers showed a higher level of education and of stress as well as a longer period of marital relationship compared to the batterers in the criminal justice system. On the other hand, the batterers who received legal punishments had more severe alcohol problems and had an accepting attitude towards the use of violence. This study also investigated psychopathology among batterers using MCMI-III, based on 333 subjects. In terms of the mean scores, there were no subscales associated with personality pathology in all the male groups. Based on the logit model, the community batterers showed a stronger tendency towards having a passive-aggressive personality than did their counterparts, and they recorded a higher level of narcissism compared to the court-referred battering men. Post-traumatic stress was the only symptom that distinguished the batterers who received legal punishments from the other groups. The theoretical and practical implications of these results were pointed out and discussed in the paper.

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The Food Safety of Superfine Powder (Phellinus linteus) Processed by Nanomill in C57BL/6 Mice (C57BL/6 마우스에서 나노밀 가공된 초미세분말(상황버섯)의 식이 안전성 연구)

  • Kim, Dong-Heui;Teng, Yung-Chien;Yoon, Yang-Sook;Qi, Xu-Feng;Jeong, Hyun-Seok;Joo, Kyung-Bok;Lee, Kyu-Jae
    • Applied Microscopy
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    • v.39 no.2
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    • pp.133-139
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    • 2009
  • A officinal mushroom, Phellinus linteus (PL) has been known to exhibit potent biological activities including antioxidative and anticancer effect. PL is consumed as a type of powder or extract for the purpose of health promotion and disease treatment. Recently superfine PL products was commercialized according to the development of pulverizing technology such as nanomill, so the evaluation of food safety is suggested. This study was conducted to evaluate the food safety of superfine PL (SPL) through hematological, biochemical and histological examination in mice as compared with fine PL (FPL). In the particle size distribution in volume after nanomill processing, the mean diameter of SPL and FPL particles was 11.78 ${\mu}m$ and 216.1 ${\mu}m$, and d (0.5), the particle diameter measured at 50% of distribution was 5.5 ${\mu}m$ and 147.9 ${\mu}m$, respectively. As the result of body weight, food intake and the weight of organs, SPL group didn't show any statistical difference compared with FPL group and normal group (N). Hematological and biochemical values were also involved in the normal range, although ALT (N vs. FPL, P<0.001) and BUN (N vs. FPL, P<0.01; N vs. SPL, P<0.01) showed significance compared with N group but there are no significance between FPL and SPL group. In the result of histological examination with liver, kidney, spleen, and small and large intestine, abnormal findings such as inflammatory reaction and histological changes were not observed. Our results suggest that the oral intake of SPL diet is not harmful to the animal in the hematological, biochemical and histological aspects although particle size was reduced to the level of superfine. However, further study will be necessary to confirm the histological safety in relation to the gastrointestinal contact of superfine particles in the case of large amount and long-term intake.

Formation of Clay Minerals by Water-Rock Interaction in the Fracture of Gneiss (편마암 열극에서의 물-암석 상호반응에 의한 점토광물 생성)

  • Jeong, Chan-Ho;Kim, Soo-Jin;Koh, Yong-Kwon
    • Journal of the Mineralogical Society of Korea
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    • v.7 no.1
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    • pp.49-61
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    • 1994
  • As the groundwater flows along the fractures of crystalline rocks, it will be in contact with the fracture walls mostly coated by secondary minerals which are quite different form those of host rocks. The presence of fracture-filling minerals in crystalline rocks is important on the view point of radioactive waste disposal because of their great surface reactivity. The Surichi drill hole of 200 m in depth in the Yugu area composed mainly of Precambrian gneiss was selected to study the formation process of clay minerals on the fracture wall of gneiss, and their relation with present groundwater. The water-rock interaction in fractures resulted in the formation of gibbsite and clay minerals. They are formed by two different processes : (1) Incongruent dissolution of feldspar by groundwater diffused from a fracture path into rock matrix produced smectite and illite in situ, (2) on the wall of fracture, gibbsite, kaolinite, smectite and illite are formed by precipitation of dissolved species in groundwater. They show the paragenetic sequence such as gibbsite${\leftrightarrow}$kaolinite${\leftrightarrow}$smectite or illite. The paragenetic sequence of fracture-filling minerals was controlled by increase of pH of groundwater, decrease of fracture permeability by precipitation of fillings, and immobility of alkali or alkaline earths in groundwater. The groundwater from the Surichi borehole is a $Na-HCO_{3}$ type with pH range of 8.6-9.2. The sodium and bicarbonate in groundwater would be supplied by the dissolution of albite and calcite, respectively. The saturation index of groundwater and surface water calculated by WATEQ4F indicates that gibbsite and kaolinite are under precipitation to equilibrium state, and that smectite and illite are under equilibrium to redissolution environment. The stability relation of clay minerals in the $Na_{2}O-Al_{2}O_{3}-SiO_{2}-H_{2}O$ system shows that kaolinite is stable for all waters.

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Cultural Implications of Korean Traditional Woodcraft Furniture (한국 전통 목가구의 문화적 함의)

  • Lee, Choon Sig
    • 대한공업교육학회지
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    • v.38 no.1
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    • pp.259-274
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    • 2013
  • Culture is already deeply imbued in our lives. The furniture has become a way of life and the human became part of the culture. In this study, the aim is to explore the traditional furniture that is projected through the culture as a lifestyle. Therefore, the purpose of this study is to explore the cultural implication in Korean traditional wooden furniture. Specific research questions in this study are as follows; 1) How to reflected house structure culture at traditional woodcraft furniture? 2) How to reflected interior space culture at traditional woodcraft furniture? 3) How to projected life form style culture at traditional woodcraft furniture? 4) How to harmonize between modern life culture and traditional woodcraft furniture? In order to achieve the purpose of this study, the literature of review was used masters of Korea's traditional woodcraft furniture. To collect information of Korean traditional furniture, the furniture was selected representative pieces of Korean Joseon Dynasty and interviewed an important intangible cultural asset somokjang. Based on the explore of Korean traditional furniture, the conclusions of this study are as follows; first, in the viewpoint of house framework culture, most of traditional furniture was made u sing a narrow interior space and was to be placed in close contact with the walls, and was developed as a type of molding on the front of the furniture to pursue beauty. Second, in the viewpoint of ondol culture, traditional furniture was closed to the wall by using low height furniture and furniture legs the structure punghyeol was used to reflect the phenomena of convective heat and humidity. Third, in the viewpoint of life form culture, traditional furniture was made that sat-down at eye level configuration is proportional to its size and height and appropriately been made. And patterns reflect the wishes of most things in nature and to be blessed with longevity origin were used in the decoration of wooden furniture. Finally, in the viewpoint of modern life culture, traditional furniture is simple but not dirty, and splendid but not luxurious. So although traditional wooden furniture are in any room or place, never discouraged by the dignity.