• Title/Summary/Keyword: lumber

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Combustion Properties of Construction Lumber Used in Everyday Life (생활 주변에서 사용되는 건축용 목재의 연소성)

  • Woo, Tae-young;You, Jisun;Chung, Yeong-jin
    • Fire Science and Engineering
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    • v.31 no.2
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    • pp.37-43
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    • 2017
  • The combustion characteristics of four kinds of wood specimens, such as Japan cedar, spruce, lauan, and red pine, were tested using the standards of Cone calorimeter (ISO 5660-1, 2) and smoke density tester (ASTM E 662). Japan cedar caught fire the quickest but the mean heat release rate was the lowest, $58.52kW/m^2$. The mean heat release rate of red pine appeared to be the highest, $71.75kW/m^2$. The lauan and Japan cedar generated relatively large amounts of carbon monoxide while the red pine and the spruce generated relatively large amounts of carbon dioxide. The red pine generated large amounts of smoke and the spruce generated the least amounts of smoke than the other samples. The total smoke release rate in the dynamic method was the highest in red pine and the lowest in spruce. The smoke density of red pine in the static method was highest in the non-flaming and flaming methods. In the non-flaming method, the smoke density of lauan was the second highest, whereas the flaming method was the least. In terms of the heat release rate, the fire risk from red pine was highest among the four test specimens. From the viewpoint of smoke generation, red pine was the most dangerous material in both dynamic and static methods.

Development of Pitch Pine Glued Laminated Timber for Structural Use -Improvement of Bending Capacity of Pitch Pine Glulam by Using Domestic Larch Laminars- (리기다소나무의 구조용 집성재 이용기술 개발 -낙엽송 층재와의 혼합 구성을 통한 집성재의 휨성능 향상-)

  • Kim, Kwang-Mo;Shim, Kug-Bo;Park, Joo-Saeng;Kim, Wun-Sub;Lim, Jin-Ah;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.6
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    • pp.13-22
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    • 2007
  • This study was carried out to scrutinize possibility of manufacturing pitch pine (Pinus rigida) glued laminated timber in order to add values of pitch pine trees. Also, it was investigated to improve bending performance of pitch pine glulam. Pitch pine was imported as one of major plantation species in Korean peninsula. Machine stress rated grades of pitch pine lumber mostly ranged between E7 and E9. which grades were more or less inferior to producing high quality glulam. However, the adhesive properties between pitch pine and pitch pine, and between pitch pine and Japanese larch (Larix kaempferi Carr.), such as shear bond strength, wood failure rate and de-lamination rate of bonded layer submerged in cold and boiling water, were higher than Korean Standard criteria. These properties are essential for manufacturing glulam with single species or multiple species. The modulus of rupture (MOR) of pitch pine glulam exceeded the criterion of Korean Standard for glulam strength grade but modulus of elasticity (MOE) was lower than the criterion. On the other hand, the bending performances (MOR and MOE) were improved 20 percent by mixing with Japanese larch laminar. It is effective to arrange higher quality Japanese larch laminar at the outer layer of glulam for improving bending performances. In conclusion, it is possible to use low quality pitch pine as laminar of structural glulam for adding values of pitch pine.

Epidural Ketamine for postoperative Analgesia -Comparison with Epidural Morphine- (경막외케타민 주입을 이용한 술후 통증관리 -경막외몰핀과의 비교-)

  • Kim, Han-Soo;Baik, Seong-Wan;Kim, Inn-Se;Chung, Kyoo-Sub
    • The Korean Journal of Pain
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    • v.1 no.2
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    • pp.192-198
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    • 1988
  • Sixty patients, of ASA physical status class I for elective operations in the lower abdomen, perineum, or lower extremities, were studied in a comparative prospective trial to evaluate the efficacy of epidural morphine and ketamine for postoperative analgesia. They were divided into two groups: an epidural morphine sulfate group (EMS group; 30 patients), and an epidural ketamine hydrochloride group (EKH group; 30 patients). Indwelling epidural catheters were placed in the patients' lumber areas (L3-4) and then all patients were anesthetized with thiopental, nitrous oxide, and halothane. After the patients had fully recovered from the anesthesia, the analgesic agents were administered epidurally via the catheter when the patients complained of pain in the postoperative period. The groups were given either 0.1 mg/kg of morphine sulfate or 0.5 mg/kg of ketamine hydrochloride administered in a volume of 10 ml of normal saline. Patients were observed for the onset and duration of postoperative analgesia and for other effects. Total doses were $5.7{\pm}0.6\;mg$ of morphine sulfate in the EMS group and $27.9{\pm}3.3\;mg$ of ketamine hydrochloride in the EKH group. The onset of analgesia was detectable within 35 min.($23.5{\pm}6.3$ min) in 86.7% (26 cases) of the EMS group and within 10 min. ($7.8{\pm}3.7$ min.) in 76.7% (23 cases) of the EKH group. Mean duration of postoperative analgesia was $22.3{\pm}2.1\;hr$. in the EMS group. In the EKH group, the duration of analgesia was shorter and variable, the range of duration was from 2 hr. to 24 hr., Cardiopulmonary changes were statistically insignificant ih both groups. Side effects such as nausea, vomiting, urinary retention, pruritus, dizziness, and headache were observed in EMS group. In the EKH group, there was no discomfort except dizziness (3 cases) and headache (1 case). Epidural ketamine was a safe technique for postoperative analgesia, but because of the variability and relative shortness in the duration of analgesia the use of this technique will require further clinical trials.

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Development of Structural Glued Laminated Timber with Domestic Cedar (국산 삼나무를 이용한 구조용 집성재 이용기술)

  • Kim, Kwang-Mo;Shim, Sang-Ro;Shim, Kug-Bo;Park, Joo-Saeng;Kim, Wun-Sub;Kim, Byoung-Nam;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.3
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    • pp.184-191
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    • 2009
  • In the southern part of the Korean Peninsula including Jeju-island, the production amount of domestic cedar has increased gradually. However, their low qualities, expected to be caused by the low density and frequent knots, have restricted their practical utilization as the high value-added products. In this study, it is aimed to look for the new uses of domestic cedar and to examine the applicability for lamination lumbers of structural glued laminated timber (glulam). Above all, machine stress ratings for individual sawn lumbers confirmed that modulus of elasticity (MOE) of cedar lumber was lower than that of other common softwood species in Korea. On the other hand, cedar lumbers have enough stiffness to manufacture the structural glulam in accordance with Korean Industrial Standard (KS). The bonding strength and durability also met the KS limitation. Nevertheless, from the result of bending tests for cedar glulam, it was shown that the modulus of elasticity (MOE) did not meet the KS limitation. Therefore, it was concluded that additional researches were needed for reinforcing the stiffness of cedar glulam.

The Effects of the Balance Training Program on the Excercise Performance and Injuries (정적균형훈련이 운동수행력 및 상해발생에 미치는 영향(탄성을 이용한))

  • Park, Sung-Hark
    • Journal of Korean Physical Therapy Science
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    • v.11 no.3
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    • pp.14-27
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    • 2004
  • This study approaches the effects of Balance Training on excercise performance and the prevention from the injuries caused by excercise. The subjects of the Balance Training program are female exercise beginners and the research period covers 8 weeks from January 10 to March 7, 2003. The research objects are 19 female golf beginners in 30s to 40s, who live in Seoul or Seongnam in Gyeonggi province and have played golf less than 6 months. The programs of the Balance Training and exercise performance were conducted to an 11 experimental group among the 19 research objects at the same time, and only the exercise performance program was applied to an 8 control group for 8 weeks. Before and after 8 weeks' application of the research programs to each group, the research subjects were examined, especially the components of their bodies, the balance and the performance capability were measured both before and after the test. The frequency of injuries by exercise was measured after the test, and the difference of the frequency was compared with the frequency before exercise. First, the experimental group, in a measurement of balance, showed that SN, MB, SAr and SAg of static balance decreased in a situation of MEO, MEC, GEO, GEC, TBEO, TBO, FHEO, FEO(p <0.05), but the control group increased. Second, the analysis on the change of exercise performance indicated better improvement in distance, ball speed, and accuracy of the experimental group than the control group(p<0.05). Third, the experience of injuries showed that there were 2 injuries in the experimental group and 11 injuries in the control group. The injured parts were 2 cases in the hands and fingers of the experimental group, and 1 case in the shoulder, 4 in the elbows, 4 in the hands and fingers and 2 in the lumber of the control group. From the above-mentioned results, it is recognized that the Balance Training program improved the exercise performance of female golf beginners and had good effects on the prevention from injuries. Accordingly, if this program is applied to sports-beginners, it will contribute to the improvement of the public health.

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The Types and Characteristics of Rural Housing in Ulleungdo Mountains (울릉도 산지 촌락 가옥의 유형과 특성)

  • Lee, Jeon
    • Journal of the Korean Geographical Society
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    • v.51 no.3
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    • pp.441-454
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    • 2016
  • This study deals with the contemporary rural housing with special reference to the roof types/materials and the outer wall materials in Ulleungdo Mountains. The most frequent roof type of rural housing is the hip-and-gable roof type(42.1%); and the next, the gable roof type(25.8%). For the roof materials, the precoated steel plate(69.1%), the asphalt shingle(11.8%), and the cement(10.7%) are the most frequent but the roofing tile and the artificial slate are not used. And for the outer wall materials, the cement(27.5%), the siding(21.3%), the corrugated galvanized iron(16.8%), and the lumber sheet(6.7%) are the most frequent. It is the hip-and-gable roof housing type with the precoated steel plate(roof materials)(41%), or the hip-and-gable roof housing type with the precoated steel plate(roof materials) and the cement(outer wall material) (18.0%) that is the most frequent type of rural housing in Ulleungdo Mountains. For the roof/wall materials, the ratio of the corrugated galvanized iron is high probably due to the relatively low cost of transport, and the ratio of the roofing tile, the artificial slate, the red brick, and the building stone is very low probably due to the relatively high cost of transport.

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A Study on the Origination of Backcountry Litter in Moaksan Provincial Park (모악산도립공원의 산쓰레기 발생특성)

  • Rho, Jae-Hyun;Huh, Joon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.35 no.5
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    • pp.64-72
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    • 2007
  • This study investigated the types, forms, and origination of litter found along one hiking course in Moaksan Provincial Park, 'Jungin-ri Course'(entrance-ridge-valley-peak). In addition, a survey was conducted to understand hikers' litter control awareness in order to determine possible backcountry litter control measures. The following are the results of this study: 1. For the litter Sequency investigation, 199 recyclable pieces of litter were found on the mid-slope(61.6%), 89 by the entrance(27.6%), 19 in the valley(5.9%) and 16 on the peak(4.9%). A total of 323 pieces of litter were found. Paper materials were the most common, followed by plastic containers such as PET bottles and yogurt containers. Of particular interest, 288 papers and cans were found on the mid-slope(46.9%). By the entrance, more plastics and bottles were found. 2. There were 614 pieces of flammable litter collected and only 19 pieces of non-flammable. Most of the flammable litter, including snack pacts, plastic bags, processed lumber, cigarette butts, tissues, cigarette boxes, and fabric was found on the mid-slope. 3. Very little food waste was found throughout the whole site proving that the policy prohibiting hikers from cooking and eating at the designated sites has been effective. However, food waste is difficult to find because it naturally decays with time. 4. $X^2$-test was used to find different types of litter and their verified origination frequency. It was found that recyclable litter, and food waste took about 1%. In addition, recyclable litter, especially bottles, was found relatively frequently by the entrance. Flammable litter was found most often at the peak. 5. The questionnaire results showed that 48.2% of the respondents "shorten their hiking journey and purchase food outside the entrance" and 29.6% said that they "bring a packed meal from home". Only 8.2% said that they "cook something when an appropriate location is found". At the Jungin-ri course, a few hikers brought their own food to eat or cook, but most hikers purchased something to eat onsite. 6. The results of the question about having experience littering while hiking showed that 19.3% litter and 79.2% do not. Those that responded "yes" gave various reasons for littering. 63.6% claimed, "there are no designated trash containers". 15.9% said they litter subconsciously. Finally, 3.2% insist that they litter "because food naturally decomposes". 7. As a result of the overall satisfaction according to the Likert scale and the analysis with an average of 14 variables, it was found that the average "toxic litter control convenience" was 2.41 with very low satisfaction. Thus, the results indicate the importance of providing appropriate back country litter control facilities.

Macroscopic Analysis of Traffic Flow in the Korean Coastal Waterway (한국연안의 해상교통류분석(I))

  • 이철영;문성혁;최종화;박양기
    • Journal of the Korean Institute of Navigation
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    • v.10 no.2
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    • pp.31-55
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    • 1986
  • Generally, the development of shipping is characterized by the amount of traffic flow (traffic volume) and seaborne cargo in the sea. Movement of ships is an essential element of constructing the traffic flow which is represented the dynamic movement of ships in the sea, but on the other band the numbers of arriving and departing the port is the basic factor consisting of the static movement of ships. The amount of cargoes by coastal vessels and ocean trade vessels have increased tremendously with the great growth of the Korean economy these days. This increase of the seaborne cargoes has made the Korean coastal traffic flow so congested that this can be a cause of large pollution as well as great marine casualities such as a loss of human lives and properties . And also the future coastal traffic is expected to increase considerably according to our economic development and high dependence upon foreign trade. Under the circumstance, to devise the safety of coastal traffic flow and to take a proper step of a efficient navigation, there is a necessity for analyzing and surveying the coastal traffic trend and the characteristics of cargo movement. In order to grasp the dynamic movement of ships in the Korean coast, O/D analysis is executed. This paper aims to secure the basic data necessary for a comprehensive plan and estimation of vessel traffic management system for the enhancement of safety, order and efficiency of vessel traffic in the Korean coast. The analyzed results of the traffic flow and seaborne cargoes of the Korean coast are summarized as follows : 1) The congestion by the vessels occurred around the ports such as-in proportion of ship's number (proportion of tonnage) -Incheon 18.5%(14.8%), Pohang 5.9% (9.9%), Samil 5.2%(8.3%), Mokpo 8.6%(0.8%), Pusan 13.5%(36.4%), Ulsan 9.1%(16.2%). 2) It is found that the area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed thatthe area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed that the coastal vessels are main elements constituting the coastal traffic and that there are much traffic flow among five ports as following through the precise O/D analysis of ship's coastal movement. Incheon-Samil, Ulsan, Pusan, Jeju Pusan -Samil, Ulsan, Incheon, Jeju Pohang -Samil, Inchoen, Jeju Pohang -Samil, Incheon, Jeju Ulsan -Samil, Incheon, Jeju Samil -Ulsan, Pusan, Incheon 4) The amount of cargoes to abroad are in proportion about 81% of total and the amount of coastal cargoes are about 19%. Of those, cargoes in and out to Japan are about 26% and to South-east Asia are about 27%. 5) The chief items of foreign cargoes are oil(38.33%), iron ore(13.98%), bituminoous coal(12.74%), grain(8.02%), lumber(6.45%) in the import cargoes and steel material(21.96%), cement(17.16%), oil(6.81%), fertilizer(3.80%) in the export cargoes. 6) The 80.5% of total export cargoes and 92.4% of total import cargoes are flowed in five main ports. 7) The chief items of coastal cargoes are oil (42.45%), cement(16.86%), steel material (6.49%), anthracite(6.31%), mineral product(4.3%), grain, and fertilizer. Almost 92.24% of total import and export oil cargoes in Korea is loaded and unloaded at the port of Samil & Ulsan.

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Improved Fuzzy Binarization Method with Trapezoid type Membership Function and Adaptive α_cut (사다리꼴 형태의 소속 함수와 동적 α_cut 을이용한 개선된 퍼지 이진화)

  • Woo, Hyun-su;Kim, Kwang-baek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.10
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    • pp.1852-1859
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    • 2016
  • The effectiveness of a binarization algorithm in image processing depends on how to eliminate the uncertainty of determining threshold in a reasonable way and on minimizing information loss due to the binarization effect. Fuzzy binarization technique was proposed to handle that uncertainty with fuzzy logic. However, that method is known to be inefficient when the given image has low intensity contrast. In this paper, we propose an improved fuzzy binarization method to overcome such known drawbacks. Our method proposes a trapezoid type fuzzy membership function instead of most-frequently used triangle type one. We also propose an adaptive ${\alpha}$_cut determination policy. Our proposed method has less information loss than other algorithms since we do not use any stretching based preprocessing for enhancing the intensity contrast. In experiment, our proposed method is verified to be more effective in binarization with less information loss for many different types of images with low intensity contrast such as night scenery, lumber scoliosis, and lipoma images.

Basic Study on the Characteristics of Wooden Sidewalk Pavement Material using Wood Waste Chip (폐목재 칩을 활용한 목질계 보도포장재의 특성에 대한 기초연구)

  • Choi, Jae Jin;Song, Jin Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3D
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    • pp.413-420
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    • 2011
  • An experiment was conducted to suggest the road pavement material combining wooden chip crushed from little useful roots and branches from logging sites or wood waste from construction sites with urethane resin. For the specimen, the mass ratio of urethane resin to construction wood waste chip/lumber waster chip was set to three different levels of 0.5, 0.75, and 1.0, which was measured, mixed with mixer, and molded; 7 days after, tensile strength test, elasticity test using golf balls and steel balls, permeability coefficient measurement, and flammability test were executed. As the result, the tensile strength of the specimen at the dry state in the air exhibited the range of 0.2-1.1MPa, and there was no change after 7 days of aging. When submerged in water, however, the strength was partially diminished; the diminishing rate was greater for less urethane resin usage, and therefore it appears desirable to set the mass ratio of resin to the wood waste chip over 0.75 to consider the moisture intrusion by precipitation and such. As the result of elasticity test, the GB and SB coefficients of the specimen using wood waste chips and urethane resin were measured to be low at below 20%, exhibiting excellent elasticity as road pavement material. Also, the permeability coefficient was over 0.5mm/sec for specimens of all combinations, exceeding the standard value required after construction for permeable pavement material, and the flammability of wood-type pavement material was evaluated to have no practical issues.