• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.11
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• pp.1495-1504
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• 2013

Renewable energy integration and increased system complexities make system operator maintain supply and demand balance harder than before. To keep the grid frequency in a stable range, an appropriate spinning reserve margin should be procured with consideration of ever-changing system situation, such as demand, wind power output and generator failure. This paper propose a novel concept of dynamic reserve, which arrange different spinning reserve margin depending on time. To investigate the effectiveness of the proposed dynamic reserve, we developed a new short-term reliability criterion that estimates the probability of a spinning reserve shortage events, thus indicating grid frequency stability. Uncertainties of demand forecast error, wind generation forecast error and generator failure have been modeled in probabilistic terms, and the proposed spinning reserve has been applied to generation scheduling. This approach has been tested on the modified IEEE 118-bus system with a wind farm. The results show that the required spinning reserve margin changes depending on the system situation of demand, wind generation and generator failure. Moreover the proposed approach could be utilized even in case of system configuration change, such as wind generation extension.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.16-26
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• 2010

The transmission valuation methodology we propose here captures the interaction between generation and transmission investment decisions recognizing that a transmission expansion can impact the profitability of new resources investment, so that a methodology should consider both the objectives of investors in resources and the transmission planner. In this perspective, this paper purports to develop the mixed-integer programming based transmission expansion planning optimization software, which is well designed to determine the construction time and place of new generators, transmission lines, and substations as well as their capacities to minimize total expenditures related to their investment and operations while meeting technical constraints such as capacity margin, constitution ratio of power resources, spinning reserves, energy and fuel constraints, transmission line outages and losses, pi-type branching, and so on. Finally, Garver's simple system is adopted to validate not simply the accuracy but the efficiency of the proposed model in this paper.

• Conservation Science in Museum
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• v.23
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• pp.91-108
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• 2020

This study conducted non-destructive analyses of the material features of seven gilt-bronze crowns of Baekje Kingdom that were excavated in the Cheonan, Gongju, Seosan, Iksan, Naju, and Hapcheon areas. A typical Baekje gilt-bronze crown has a conical inner crown and an outer crown embellished with vertical ornaments on the front and the back, a tube topped with a hemispherical ornament, and other ornamentation. Diverse designs (e.g., dragon, bonghwang, flowers, and plants) were applied using a range of techniques, including repoussé, chasing, openwork, and engraving. Formal features differ among the crowns according to their period of production and site of excavation. The substrate metal of the crowns is either pure copper or mixed copper with a small amount of lead. The crowns were amalgam-plated on the surface with pure gold or gold with a small amount of silver. The crown from Okjeon Tomb No. 23 in Hapcheon in the ancient Gaya region has a high silver content, which appears to be a regional feature. In addition, this crown from Okjeon Tomb No. 23, which can be categorized as Baekje-style gilt-bronze crown, seems to be plated at most three times, while the gilt-bronze crowns found within Baekje Kingdom territory were plated once or twice.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.81-89
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• 2002

The Battery Energy Storage System (BESS) has lots of advantages such as load leveling, quick response emergency power (spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission construction. However, it is very critical that economic feasibility requires justification from the customer side of meter to promoting the dissemination of BESS in nation widely. In this paper, we proposed the economic assessment model of customer owned BESS which is complemented and improved the existing model. The proposed model is applied to the typical customer types, i.e. light industrial, commercial, and residential, which are taken from the statistical analysis on the load profile survey of Korea Electric Power COmpany (KEPCO). The economic viability performed for each customer load type to justifying their economic feasibility of BESS installation from the economic measures such as payback period, Net Present Worth (NPW), Rate Of Return (ROR). The results show that the BESS has economic benefits to the specific customer type, i.e. residential customer. Therefore, the government and the energy agency should be committing the support program, such as tax incentive, financial support, to disseminate the BESS nation widely. The results of this paper are useful to the customer investment decision-making and the national energy policy & strategy in Korea.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.41-54
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• 1998

연구목적 : 사상의학(四象醫學)은 인간을 태양인(太陽人), 태음인(太陰人), 소양인(少陽人), 소음인(少陰人)으로 구분하여 동일한 병증에 대해서도 치료를 달리하는 의학이다. 즉 인간을 동일한 원리로 설명하는 것이 아니라 각 체질에 따른 차등성을 통해 각 체질 취약점의 보완을 추구하는 의학이다. 그러면, 무엇이 이러한 인간 구분의 단서가 되었으며 이것이 의학으로까지 적용되는 과정 즉, 사상의학의 성립 과정을 살펴 보는 것을 연구 목적으로 한다. 연구방법 : 동무(東武) 이제마(李濟馬)의 저술로 인정되는 "격치고(格致藁)", "동무유고(東武遺藁)", "동의수세보원(東醫壽世保元)"의 문헌적 자료와 각 편의 저술시기를 통해 동무(東武) 이제마(李濟馬)의 사고의 흐름과 변화를 통해 사상의학이 성립되는 과정을 살펴 보는 문헌적 조사방법을 이용하였다. 연구 결과 및 결론 : 이상의 결과를 통해 아래의 연구 결론을 구하였다. 1. 동무(東武)는 "맹자(孟子)"의 사부지심(四夫之心)을 근거로 인간을 심욕에 따라 비인(鄙人), 박인(薄人), 탐인(貪人), 나인(懦人)으로 구분하였고 인의예지의 사단을 장부에 배속하여 심욕을 몸에 적용하였다. 그러나 "격치고(格致藁)"의 비인(鄙人), 박인(薄人), 탐인(貪人), 나인(懦人)과 "동의수세보원(東醫壽世保元)"의 태소음양인(太少陰陽人)의 직접 연결은 동무 사고의 시간적 흐름을 고려하지 않은 것이며, 동무는 "동의수세보원(東醫壽世保元)" "사단론(四端論)"과 "확충론(擴充論)"을 통해 비박탐라인(鄙薄食懦人)의 심욕(心愁慾)과 태소음양인(太少陰陽人)의 정기(情氣)를 매개로 하여 비인(鄙人)은 태양인(太陽人), 탐인(貪人)은 태음인(太陰人), 박인(薄人)은 소양인(少陽人), 나인(懦人)은 소음인(少陰人)으로 설명함을 확인할 수 있었다. 2. "격치고(格致藁)" "독행편(獨行篇)"과 저술 연도가 동일한 "동무유고(東武遺藁) 교자평생함(敎子平生箴)"을 통해 의학적 사고의 성립을 살펴보면, 동무(東武)의 차등적 장리(臟理)는 희노애락의 성정(性情) 구분이 장리(臟理)의 차이로 발전한 것이 아니라 장부(臟腑) 강약(强弱)에 대한 인식이 선행되고 이를 희노애락(喜怒哀樂)으로 설명하였으며, 또한 "동의수세보원(東醫壽世保元)"의 장부(臟腑) 대소(大小)는 강약(强弱)에 근거한 개념임을 알 수 있었다. 3. 사상의학(四象醫學)의 의학적 설명 도구는 희노애락(喜怒哀樂)이다. 희노애락은 비박탐라(鄙薄貪懦)와는 달리 선악(善惡)의 가치 판단이 들어있지 않으면서 기의 승강을 나타낼 수 있는 중용적 설명 도구로 동무가 의학을 설명하기 위한 최선의 도구였다. 사상의학(四象醫學)에서의 희노애락(喜怒哀樂)은 증치의학(證治醫學)의 음양오행(陰陽五行)의 역할과 같은 것이다. 4. 희노애락(喜怒哀樂)은 "동의수세보원(東醫壽世保元)"에서 성(性), 정(情), 기(氣)로 설명되는데 희노애락의 성(性)과 정(情)은 장부 대소를 설명하는 근거로 체질마다 다른 장국 형성을 가능하게 하고 또한 각기 표기(表氣)와 리기(裏氣)를 손상(損傷)하는 것으로 설명되었다. 희노애락(喜怒哀樂)의 기(氣)는 기(氣)의 승강(升降)을 설명하는 근거로 애기(哀氣)와 노기(怒氣)는 양(陽)으로 직승(直升)과 횡승(橫升)하고 희기(喜氣)와 락기(樂氣)는 음(陰)으로 방강(放降)과 함강(陷降)한다. 이러한 희노애락은 순동역동(順動逆動)의 특성과 상성상자(相成相資)의 특성을 지니는데 희노애락(喜怒哀樂)의 상성상자(相成相資)는 사상의학 고유 개념으로 사상인병증론(四象人病證論)에서 언급하고 있는 성정(性情)과 심욕(心慾)의 편급까지 영향을 미치는 중요한 단서이다.

• Conservation Science in Museum
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• v.26
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• pp.119-142
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• 2021

The gilt-bronze-and-silver shoes, excavated from the Tomb of King Muryeong, revealed many defective parts, which constantly raised in-depth re-investigation and reporting. In that point, scientific treatment and analysis were conducted to investigate the manufacturing techniques applied. The conservation treatment was carried out with an emphasis on the restoration of the original form and joining parts. As a result, the upper part of the right shoe and some part of the back heel were joined, confirming the joining method and the number of rivet used for instep bonding. From the component analysis, it is presumed that the outer plate was gilded with mercury amalgam on pure copper, and pure silver was used for the inner plate. The main pattern of the gilt-bronze-and-silver shoes includes designs of phoenix, lotus, and six-petal flower, while the lotus pattern is high in terms of ratio. Thus, youngnaksa(twisted gilt-bronze thread), geumdongsa(gilt-bronze thread), wondujeong (rivet), and samyeonjeong(quadrangular cleats) were used for bonding each plate. Twisted gilt-bronze thread was used to join the inner and outer plates, while the center and rear of the inner plate were combined with only gilt-bronze threads. From the fact, it is presumed that the joining method was different whether the function was decoration or just bonding. Regarding the manufacturing process, traces of burnishing were confirmed on the outer surface of the gilt-bronze and silver shoes, but no burnishing traces were identified on the inner surface of the silver plate, which is likely to prove more importance put on the finishing of the outer plates rather than that of the inner.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.40-47
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• 1987

Under the different conditions of planting density and compound fertilizer level, some agronomic and chemical characteristics of burley tobacco were investigated from 1982 to 1984. Leaf area and dry leaf weight per plant, crop growth rate, relative growth rate and net assimilation rate for 40-60 days after transplanting were higher with increasing plant spacing and fertilizer, but leaf area index was lower with increasing plant spacing. At topping stage, the leaf size was increased with increasing plant spacing and amount of fertilizer applied and the stem diameter was increased by increasing plant spacing. Leaf area, leaf weight per plant and weight per unit leaf area of harvested leaf were higher when plant spacing and fertilizer increased. It was estimated that the optimum plant spacing was 105cm x 34cm and level of com-pound fertilizer (N-P$_2$ O$\sub$5/ -K$_2$O =10-10-20) was 263kg/l0a for high yield. There were trends toward increase the contents of total alkaloid and total nitrogen with increasing plant spacing and fertilizer application. There was significant positive correlation between plant spacing and total nitrogen, and between fertilizer application and total nitrogen. The plant spacing of 105cm x 35 to 40cm and 227.5kg/l0a of fertilizer level may be profitable for farm economy and the low nitrogenous leaf.