• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.10
• /
• pp.761-765
• /
• 2009

This research aims an optimal placement of Mobile Base Station (MBS) under HAP based network configurations with the restrictions of HAP capabilities. With clustering algorithm based on BIRCH, mobile ground nodes are clustered and the centroid of the clusters will be the location of MBS. The hierarchical structure of BIRCH enables mobile node management by CF tree and the restrictions of maximum nodes per MBS and maximum radio coverage are accomplished by splitting and merging clusters. Mobility models based on Jeju island are used for simulations and such restrictions are met with proper placement of MBS.

• Food Science and Preservation
• /
• v.24 no.3
• /
• pp.343-350
• /
• 2017

Effects of high pressure processing on physicochemical and microorganisms properties in birch sap were investigated using variable high pressure processing conditions. The viable cell counts of untreated birch sap was 4.0 log CFU, whereas high pressure processed sap were not detected. In birch sap was treated with 450 to 550 MPa, microorganisms were not detected during storage period, and physicochemical properties as well as color were slightly changed. The more processing time and pressure, its quality variations were more stable and then its optimum processing condition was determined with 120 sec at 550 MPa. The microorganisms and physicochemical properties of treated birch sap were investigated during storage at $5^{\circ}C$ and $10^{\circ}C$ for 45 and 28 days. Changes of physicochemical properties of treated birch sap were smaller than those of the untreated, but viable cell count were not detected during storage period. As for pH, $^{\circ}Brix$, and turbidity result of birch sap, quality shelf life of control and treatment were 4 and 24 days, respectively. Especially, ${\Delta}E$ value of instrumental color was untreated birch sap 4 days similar with the high pressure processed it for 28 days. These results indicated that the high pressure processing can be used as an effective method to improve the shelf life of birch sap.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.3
• /
• pp.93-99
• /
• 1998

Lately public interest in tree saps of maple and birch trees stimulated to increase demands for sap drink as a natural medical beverage. In order to understand factors affecting tree sap flows, birch species, particularly Betula platyphylla in Mt.Sobaek area, were monitored for daily sap flows according to factors, such as DBH, tapping hole sizes and direction of hole drilling on the trunks. The chemical constituents of saps were also analyzed. The sap flow initiated from the end of March and finished at the end of April. The flow maxima appeared from April 14th to April 26th. Total amounts of the sap flow obtained from birch tree were over 1,800 ml per day per one tree. Sap flows were increased with increasing DBH and tree age. Six milimeter drilled hole resulted in the highest sap flows. Sap flows increased with increases of diameter and height of the trees. Hole drilling to downward side(south-facing) of tree produced almost doubled sap flows than that of upward one(north-facing), while rightside drilling produced same amounts of saps to that of leftside one. Six mm drilling gave the best results not only in maximum flows but also effective hole occluding rates. The saps have in the range of 4.5 to 5.6 pH and l.0 - 2.0% of saccharinity. Sucrose, glucose, fructose and high mineral contents were found in the saps of birch tree. The tree saps could be utilized not only medicinal drink, but also one of the healthy beverages.

• Korean Journal of Heritage: History & Science
• /
• v.56 no.2
• /
• pp.206-220
• /
• 2023

In the royal publishing process of the Joseon Dynasty, the main species of wood used for woodblock printing was recorded as Jajak-mok. Although the name Jajak-mok may suggest Jajak-namu(white birch), it is presumed to refer to a different type of wood than Jajak-namu based on its recorded habitat and usage in historical documents. The aim of this paper is to clarify that during the Joseon Dynasty, the term Jajak-mok referred to Geojesu-namu (Korean birch), while Jajak-namu was called Hwa-mok(樺木). Additionally, this paper explores how the term Jajakmok eventually became the name of white birch, Jajak-namu, used today. In the mid-18th century, Japan used the character 樺(hwa) to refer to Beot-namu(Sargent cherry). As Japanese encyclopedias entered Joseon, the term Hwa-mok began to refer to both Beot-namu and Jajak-namu, which is also called Bot-namu. Since the pronunciation of Boet-namu and Bot-namu are similar, the two trees were eventually unified under the name Boet-namu. In the 20th century, the official names of three trees were established. According to notifications issued by the Ministry of Agriculture and Commerce of the Korean Empire in 1910 and the Governor-General of Chosen in 1912, Hwa-mok(white birch) was renamed asJajak-namu. In 1968, Beot-namu(Sargent cherry) retained its original name, and Jajak-mok(Korean birch) was remained . In modern Chinese character dictionaries, the meaning of 樺(hwa) is listed as "1. Beot-namu(Sargent cherry), 2. Jajak-namu(white birch)." From this, we can infer the historical background in which the names of these three trees were mixed up.

• Korean Journal of Food Science and Technology
• /
• v.41 no.4
• /
• pp.413-416
• /
• 2009

The sap of the white birch is one of the most widely used herbal medicines to treat gastrointestinal tract, jaundice, and various periodontal diseases. The purpose of this study was to measure the effect of white birch sap on in vivo immune agents in mice. The treatment of white birch sap on the forced swimming test has been used as a screening model for new immune enhancement agents. The hematological examination was significantly different in neutrophil, lymphocyte, and monocyte counts between treatment and control groups. Moreover the white birch sap changed the phagocytic index, immobility duration time, and leukocyte counts in mice.

• Asian Journal of Atmospheric Environment
• /
• v.6 no.3
• /
• pp.192-205
• /
• 2012

The effects on birch (Betula spp.) of elevated carbon dioxide ($CO_2$) and ozone ($O_3$), which are both increasing in the troposphere, are surveyed in detail based on the literature. Birches establish themselves in the open field after disturbances, and then become dominant trees in temperate or boreal forests. Ecophysiological approaches include the measurement of photosynthesis, biomass, growth, and survival of seedlings and trees. Elevated $CO_2$ levels give rise to a net enhancement of the growth of birch trees, whereas high $O_3$ generally reduces growth. Although the effects of the two are opposed, there is also an interactive effect. Basic physiological responses of the single genus Betula to $CO_2$ and $O_3$ are set out, and some data are summarized regarding ecological interactions between trees, or between trees and other organisms.

• Journal of the Korea Furniture Society
• /
• v.16 no.2 s.30
• /
• pp.59-65
• /
• 2005

As physical condition of students improves, there is a need to develop human body-friendly desk and chair for students. In this study, desks and chairs were manufactured with curved veneer lamination under high frequency heating and pressing, using ten wood species such as Japanese red pine, Korean pine, pitch pine, Japanese larch, yellow poplar, black locust, oak, radiata pine, beech, and birch. The performance of these products were evaluated. The results obtained were summarized as follows; With high frequency heating, the turned lamination of veneers with full size sheet ($3{\times}6\;feet$) prepared by rotary lathe peeling was successfully applied for making the members of desk top, leg frames of desk and chair. Bending strengths of desk tops were relatively greater for yellow poplar, black locust and red pine, which were similar to those of beech and birch. Bending strengths of desk legs were classified into greater species group (red pine, yellow poplar, larch) and lower species group (radiata pine, Korean pine, pitch pine). Compressive strengths of chair legs in parallel direction to the lamination were greater in black locust and larch. On the other hand, differences between outer and inner gap at the top and drawer bottom of desk top were rather larger for the laminations of birch and beech, and less for those of yellow poplar and pitch pine, showing greater stability of open drawer space. In results, yellow poplar, larch, pitch pine and red pine showed good appearance and strength properties at the curved veneer lamination. Accordingly, it was believed that these domestic woods were able to substitute for birch which was being imported for the use of veneer-laminates type furniture.

• Journal of the Korean Wood Science and Technology
• /
• v.17 no.3
• /
• pp.1-7
• /
• 1989

This study was performed to obtain the optimal condition that hydrolyzed exploded pine(Pinus densiflora), oak(Quercus serrata) and birch wood(Betula platyphylla var. japonica) by using sulfuric acid. The results obtained were summarized as follows: In hydrolysis of wood meal with sulfuric acid. maximum yield of sugar appeared that pine was 12 hours. oak and birch were 24 hours with 65% sulfuric acid. Futhermore, when wood meal and exploded woods were hydrolyzed with 65% sulfuric acid at $23^{\circ}C$ for 6 hours(primary hydrolysis), diluted to 3% and hydrolyzed again at $100^{\circ}C$ for 2 hours(secondary hydrolysis), the maximum sugar yield of wood meals were 6 hours. those of higher steam exploded pine wood was 3 hours. of lower steam exploded oak and birch woods were 6 hours. The sugar analyses of exploded wood showed that the amount of arabinose and xylose residue rapidly decreased. content of nemicelluose decreased with increase of steaming time and pressure.

• Journal of Conservation Science
• /
• v.30 no.1
• /
• pp.33-38
• /
• 2014

The adhesive material was found for joining pottery fragments from Duurlig Nars, Mongolia estimated in AD 1C. In this study, analysis of natural substance for joining fragments of pottery was performed using gas chromatograph and mass spectrometer. As a result, it was identified triterpenoid substances, such as lupeol and betulin which were known to constituents of birch bark tar. It was suggested that Mongolian used adhesives made by birch bark tar for joining pottery fragments. Therefore if organic materials of ancient objects are systematically researched, it can provide significant evidence related to the way of life of ancient people.

• Journal of the Korea Furniture Society
• /
• v.22 no.4
• /
• pp.245-251
• /
• 2011

The purpose of this research is to provide new direction on the field of the furniture design and to establish the identity of Korean furniture design as the flow of craft's juxtapose mixture era where it mix and match Korean traditional craft style materials with the modern furniture design. In other words, it is intended to create new furniture design and propose beautiful Korean luxury furniture design based on the precious unique culture with the traditional craft style, juxtaposition of modern furniture, and reinterpretation. It should grant artistic values that can satisfy consumers having various tastes and scarcity values, plus it should put out aesthetic and creative expressions in furniture design putting into the beautiful traditional craft form values. Furthermore, it is required to create new design through values and spirit, materials, techniques, forms, pattern, and usages by interacting, coordinating, and combining tradition and modern East and West, plus craft and design.