• Journal of Conservation Science
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• v.33 no.5
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• pp.381-390
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• 2017

Desalination is the main focus of the stabilization of iron artifacts. However, drawbacks such as re-corrosion are noted due to the uncertainty in the elimination of the corrosive factors and artifacts. Several studies have been carried out on the effects of corrosion inhibitors to overcome these shortcomings. In this study, the effects of type 3 water treatment on corrosion inhibitors were investigated. Surfaces of samples that contained film corrosion inhibitors on their surfaces were analyzed. The results revealed that the surface rust was removed from the sample of type 1 No. 2 that was mainly composed of phosphate. The average weight reduction rates of re-corrosion samples were 0.58, 0.03, and 0.07% for type 1 No. 2, type 2 No. 2, and type 3 No. 2 respectively. The changes in the $Cl^-$ ion, a corrosive agent were found to be 28.60, -4.08, and -1.94 ppm for type 1 No. 2, type 2 No. 2, and type 3 No. 2 respectively. The water-treated films were analyzed by X-ray photoelectron spectroscopy (XPS). It was found that type 2 No. 2 had less Fe the basis metal, than that in type 3 No. 2 indicating much better film. Moreover, Si content was higher in type 2 No. 2, based on the silicate content, than in type 3 No. 2. They are speculated to be the reason or the formation of a better film. Type 1 No. 2, which is mainly composed of phosphate, would be inappropriate as a metal artifact conservation treatment. It was determined that type 2 No. 2 and type 3 No. 2 water treatments, which are mainly composed of silicate, provided excellent corrosion inhibiting effects. Corrosion inhibitors could be used as emergency treatment agents during the excavation of iron artifacts.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.509-520
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• 2015

A design for the merge mode of three dimensional High Efficiency Video Coding (3D-HEVC) is proposed in this paper. The proposed design can reduce the implementation complexity by removing the duplicated modules of the HEVC. For the extension codec, the implementation complexity is as crucial as coding efficiency, meaning if possible, extension codec needs to be easily implemented through by reusing the design of the legacy codec as-is. However, the existing merging process of 3D-HEVC had been built-in integrated in the inside of the HEVC merging process. Thus the duplicated merging process of HEVC had to be fully re-implemented in the 3D-HEVC. Consequently the implementation complexity of the extension codec was very high. The proposed 3D-HEVC merge mode is divided into following two stages; the process to reuse the HEVC modules without any modification; and the reprocessing process for newly added and modified merging modules in 3D-HEVC. By applying the proposed method, the re-implemented HEVC modules, which accounted for 51.4% of 3D-HEVC merge mode confirmed through the operational analysis of algorithm, can be eliminated, while maintaining the same coding efficiency and computational complexity.

• Resources Recycling
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• v.19 no.1
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• pp.33-39
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• 2010

The spheric sintered body with $6{\pm}2mm$ diameter was manufactured in a rotary kiln at $1125^{\circ}C$/15 min using green body formed by pelletizing the batch powder composing of coal bottom ash produced from power plant and dredged soil by 70:30, wt%. And the physical properties of sintered body (BD) were analyzed to confirm the possibility for applying to an absorbent to restore a contaminated soil. The sintered body had a giant pore above 100 ${\mu}m$ and a fine pore below 10 ${\mu}m$, and bulk density was 1.4. Also its specific surface area, porosity and void proportion were $12.0m^2/g$, 30.1% and 38.2% respectively. The crushed body (BD-C), produced by crushing a BD specimen into an irregular shape with a aspect ratio of about 2, was similar to BD specimen at bulk density and pore size distribution. But it had superior values of specific surface area, porosity and void proportion compared with BD specimen owing to a decreased apparent volume due to conversion of closed pore existed at interior of BD to open pore during a crushing process. The IEP of sintered body occurred at about pH=5, so the optimum pH condition of reacting aqueous solution could be known before bonding a microbe to the sintered body. Hence, the optimum void proportion and porosity of an absorbent can be obtained by appropriate mixing a BD with BD-C from the base data calculated in this study.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.146-159
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• 2019

This study focuses on the understanding of human subsistence and pottery use during ancient times on the Korean peninsula through lipid analysis of potsherds from several major prehistoric settlement sites. Ancient human subsistence has been one of the long-standing topics in Korean archaeology. However, since the high acidity of sediments does not allow long-term preservation of organic remains, we still lack some critical information related to the prehistoric diet. Pottery contains relatively well-preserved organic remains created during past cooking events. Though pottery is one of the most studied material cultures in Korean archaeology, almost no attention has been given to analyzing the pottery itself. This is a surprising omission and represents a serious gap in our understanding of prehistoric technology and subsistence. The analysis of ancient lipids extracted from the pottery matrix using GC-MS and isotope analysis can contribute to our understanding of the true nature of past subsistence strategies. Potsherd samples for the analyses in this study were collected from six prehistoric and early historic settlement sites located in the central part of the Korean peninsula. The results showed that subsistence strategies differed by both location and time period. For example, at Jungdo, an inland open-air Bronze Age settlement site in Chuncheon City, we were able to see the presence of terrestrial mammals. At Gahak-dong, Gwangmyeong City, marine resources were utilized, as the location of the site is not far from the coastline. At the early historic site of Guwol-dong, Incheon City, we were able to detect dairy products. The results of this study suggest that there was utilization of a wider range of resources among ancient dwellers in the central part of the Korean peninsula.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.606-612
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• 2019

The main causes of subsidence and sinkholes in the lower part of urban roads are sewage line foundation and inadequate compaction of backfill material. This leads to many problems, such as the breakage of joints in sewer pipes, poor connection, pipe breakage, and cracks. To solve this problem, the support factor related to the sewer foundation and the safety factor according to the excavation depth were evaluated. For the foundation of rigidity tolerance, crushed stone foundation, and abandoned concrete foundation, a recently newly developed site assembly-type lightweight plastic foundation were used. Backfill materials were applied on site (sandy soil and clayey soil) and fluid backfill was recycled onsite. To evaluate the depth of excavation and the safety factor of each sewer pipe foundation, the design load considering the load factor and the support factor was evaluated. The support coefficients were 0.377 for a crushed stone foundation, 0.243 and 0.220 for an abandoned concrete foundation ($180^{\circ}$ and $120^{\circ}$), and 0.231 for a lightweight plastic foundation and fluid backfill. Overall, the safety factor was low when using the crushed stone foundation, and the safety rate was the highest when the foreclosed concrete foundation ($180^{\circ}$) was used. In addition, when the combination of lightweight plastic and fluid backfill materials was used, the safety factor was higher than that of abandoned concrete foundation ($120^{\circ}$), which means that the newly developed lightweight plastic foundation can be used as another alternative base of a steel pipe.

• Journal of the Korea Society of Computer and Information
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• v.14 no.3
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• pp.1-11
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• 2009

XQuery query proposed by W3C is one of the standard query languages for XML data and is widely accepted by many applications. Therefore the studies for efficient Processing of XQuery query have become a topic of critical importance recently and the optimization of XQuery query is one of new issues in these studies. However, previous researches just focus on the optimization techniques for a specific XML data management system and these optimization techniques can not be used under the any XML data management systems. Also, some previous researches use predefined XML data structure information such as XML schema or DTD for the optimization. In the real situation, however applications do not all refer to the structure information for XML data. Therefore, this paper analyzes only a XQuery query and optimize by using itself of the XQuery query. In this paper, we propose 3 kinds of optimization method that considers the characteristic of XQuery query. First method removes the redundant expressions described in XQuery query second method replaces the processing order of operation and clause in XQuery query and third method rewrites the XQuery query based on FOR clause. In case of third method, we consider FOR clause because generally FOR clause generates a loop in XQuery query and the loop often rises to execution frequency of redundant operation. Through a performance evaluation, we show that the processing time for rewritten queries is less than for original queries. also each method in our XQuery query optimizer can be used separately because the each method is independent.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.103-110
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• 1994

Since the supply of the Southeast Asian tropical timber decreases and its price steeply increases in the international lumber market, door and window frame manufacturers in this country are eagerly searching for their substitutes. This is the first step to replace Southeast Asian tropical timber by low grade North American softwoods, whose reliable and steady supply is expected, but their appearances are not as good as the tropical timber. In this study, knot distribution on the softwood boards and their warp were examined The yield and production cost were also calculated. The average numbers of knots on a door frame were 7.2 for Douglas-fir and 3.4 for Western hemlock. Only 11% of the knots of Douglas-fir door frames are larger than 5cm in diameter, while are 35% of the knots of Western hemlock. The deformations of door frames, after 2 months air-drying, were measured with a warp table. The deformations of Western hemlock door frames were mostly less than 6mm, while those of Douglas-fir distributed in the range of 0.5 and 9.5mm. The yield of Western hemlock is higher than that of Douglas-fir. It can be concluded that the door frames made of the softwoods are compatible with those made of the tropical timber in most aspects except appearance.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.138-156
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• 2023

Some of the metal cultural heritage that make up a considerable proportion of Korea's cultural heritage have been installed and displayed outdoors due to their own functions, roles, and scale. Therefore, more diverse and complex damages can occur outdoors than they are in a stable environment. Therefore, it is necessary to combine accurate diagnosis and systematic survey methods in order to utilize basic data obtained from research results as data for the long-term and continuous conservation management as well as to do the research to diagnose the conservation status of outdoor cultural heritage. The clepsydra(hereinafter referred to as Jagyeongnu) of Changgyeonggung Palace, the National Treasure has been installed and displayed outdoors since it was manufactured. Though regular conservation and maintenance of the Jagyeongnu have been carried out, damage still occurred. Therefore, the scientific research on Jagyeongnu to diagnose the state of conservation was conducted prior to the full-scale conservation treatment. First, the state of conservation was investigated with an examination of basic data, macroscopic inspections and past records of repair history according to the purpose of the research. More detailed examinations were also conducted through the 3D scan, surface pattern investigation, and color difference analysis, and the analysis on materials and contaminants were conducted through P-XRF, FT-IR, and Py-GC/MS. The scientific research reveals that squalane and silicone oil have been applied in the past for conservation treatment and directly exposed to outdoor environmental factors, which caused damage to Jagyeongnu and contaminants such as dust adhered thickly to its surface, accelerating severe damage. A greater incidence of damage was found around the part with relatively high exposure effect, which corresponded with the tendency identified by grouping color difference data. As a result of integrating various research methodologies to diagnose the state of conservation and secure basic data, the causes and types of damage were identified. Furthermore, the process of obtaining digital data to be utilized in various ways, and the color difference analysis presenting visible damage as scientific data and identifying the tendency of damage patterns were confirmed to have been effective.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.69-69
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• 2011

태양열 발전 플랜트에 사용되는 중고온 범위의 축열조에 고체-액체간 상변화를 수행하는 용융염을 축열물질로 사용하면 액체상 또는 고체상만으로 된 열저장 매체에 비해 축열조의 규모를 축소함과 동시에 축열온도의 균일성 향상에 기여할 수 있다. 중온인 $250{\sim}400^{\circ}C$ 범위에서 이용 가능한 용융염으로는 질산칼륨($KNO_3$), 질산리튬($LiNO_3$)등이 있다. 그러나 이러한 용융염의 가장 큰 단점은 열전도율이 매우 낮다는 것이며, 이로 인해 요구되는 열전달률을 성취하기 위해서는 많은 열접촉면적이 필요하다는 것이다. 이러한 단점을 극복하는 방법을 도입하지 않고서는 축열시스템의 소규화를 성취하는데 큰 효과를 가져올 수 없다. 한편 열수송 성능이 탁월한 히트파이프를 사용하면 열원 및 열침과 축열물질 사이의 열전달 효율을 증가시켜 시스템의 성능 향상과 동시에 소규모화에 기여할 수 있다. 중온 범위 히트파이프의 작동유체로서 다우섬-A(Dowtherm-A)는 $150^{\circ}C$이상 $400^{\circ}C$까지의 범위에서 소수에 불과한 선택적 대안 중 하나이다. 따라서 본 연구에서는 용융염을 사용하는 중온 태양열축열조에 적용 가능한 다우섬-A 히트파이프의 성능을 파악하여 기술적 자료를 제시하고자 하였다. 열원으로는 고온 고압의 과열증기, 그리고 열침으로는 중온의 포화증기를 고려하였다. 용융염 축열조를 수직으로 관통하는 히트파이프는 하단부에서 열원 증기와 열교환 가능하며, 중앙부에서 축열물질과 열교환하고, 상단부에서는 중온 증기와 접촉할 수 있도록 배치하였다. 축열모드에서는 히트파이프의 하단부가 증발부로 작동하고, 중앙부가 응축부로 작동하여 용융염으로 열을 방출하면 용융염의 온도가 상승하고 용융점에 도달하면 액상으로의 상변화가 진행되면서 축열이 활성화된다. 축열모드에서 히트파이프의 상단부는 단열부로 작동한다. 방열과정에서는 히트파이프의 하단부가 단열된 상태이고, 중앙부는 용융염으로부터 열을 받아 증발부로 작동하며, 상단부는 중온 증기로 열을 방출하므로 응축부로 작동한다. 즉, 축열시스템의 작동모드에 따라 하나의 히트파이프에서 증발부, 응축부, 단열부의 위치가 변하게 된다. 특히, 히트파이프의 중앙 부분이 응축부에서 증발부로 전환될 때에도 작동이 보장되려면 내부 작동유체의 연속적인 재순환이 가능해야 하므로, 일반 히트파이프에서와는 달리 초기 작동액체의 충전량을 증발부 전체의 체적보다 더 많이 과충전해야 한다. 이러한 히트파이프의 성능 파악을 위한 실험에서 고려한 변수들은 열부하, 작동액체의 충전률, 작동온도 등이며, 열수송 성능의 지표로서는 유효열전도율과 열저항을 이용하였다. 중온범위에서 적정한 작동온도를 성취하기 위해 실험에서는 전압 조절기로 열부하를 조절하는 동시에 항온조로 응축부의 냉각수 입구 온도를 제어하였다. 하나의 히트파이프에 대해서 최대 1 kW까지의 열부하에서 냉각수 입구 온도를 $40^{\circ}C$에서 $80^{\circ}C$ 범위로 변화시키면 히트파이프 작동온도를 약 $250^{\circ}C$ 내외로 조절 가능하였다. 히트파이프 작동액체 충전률은 윅구조물의 공극 체적을 기준으로 372%에서 420%까지 변화 시켰다. 실험 결과를 토대로 열저항과 유효 열전도율을 각각 입력 열유속, 작동온도, 작동액체 충전률 등의 함수로 제시했다. 동일한 냉각수 온도에서는 충전률이 높을수록 히트파이프의 작동온도가 감소하였다. 열저항 값의 범위는 최소 $0.12^{\circ}C/W$에서 최대 $0.15^{\circ}C/W$까지로 나타났으며 유효 열전도율의 값은 최소 $7,703W/m{\cdot}K$에서 최대 $8,890W/m{\cdot}K$까지 변화했다. 최소 열저항은 충전률 420%인 경우에 나타났는데 이때의 작동온도는 약 $262^{\circ}C$이었다. 히트파이프의 작동한계로서 드라이아웃(dry-out)은 충전률 372%의 경우에 열부하 950 W에서 발생하였으나, 그 이상의 충전률에서는 열부하 1060 W까지 작동한계 발생이 관찰되지 않았다. 실험 결과 본 연구에서의 히트파이프는 중온 태양열 축열조에 적용되어 개당 약 1 kW의 열부하를 이송하면서 축열물질 및 축방열 대상 유동매체와 열교환을 하는데 사용하는데 충분할 것이라 판단된다.

• Journal of KIISE:Software and Applications
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• v.30 no.10
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• pp.955-972
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• 2003

As the next significant software abstraction, software agents have generated lots of excitements in recent years because of its promise as a new paradigm for conceptualizing, designing, and implementing software systems. This promise is particularly attractive for creating software that operates in environments that are distributed, open, and complex, such as the Internet. The effort of developing agent systems have, however, suffered from lack of generalized agent architecture because of various properties of an agent and nonexistence of a standard agent architecture. An agent architecture is an important criterion in order to not only identify agents in their domain but also determine the software architecture of the system. The major contribution of the work described here is an object-oriented design of an agent architecture that addresses fundamental properties, which are autonomy and interaction. Object-oriented design method is used for identifying the internal modules of an agent architecture and organizing correlation between the modules are identified.