• Management & Information Systems Review
• /
• v.24
• /
• pp.1-24
• /
• 2008

This paper examines the direct effects of board independence and also its interaction effects with CEO's firm specific experience on firm performance. The findings in an hierarchial regression analysis of multiyear sample of computer hardware companies indicate that independent, outsider directors are beneficial to firms' performance when CEO has high-level of firm specific experience whereas it is harmful when CEO has low-level of firm specific experience. However, separating the positions of board chair and chief executive officer that has been used as another means for increasing board independence does not influence to firms' performance. These findings imply that researchers in corporate governance should reconsider the relative weight placed on directors' monitoring and assistance role. Rather than focusing predominantly on directors' willingness or ability to control executives, in future research scholars should yield more productive results by focusing on the assistance directors provide in bringing valued resources to the CEOs and in serving as a source of advice and counsel especially for CEO's improvement of management technique. In addition, they should pay more attention on identifying intervening processes between board and firm performance in order to provide optimal governance mechanisms and configurations to practitioners.

• Current Optics and Photonics
• /
• v.1 no.5
• /
• pp.505-513
• /
• 2017

Measuring the thickness of thin films is strongly required in the display industry. In recent years, as the size of a pattern has become smaller, the substrate has become larger. Consequently, measuring the thickness of the thin film over a wide area with low spatial sampling size has become a key technique of manufacturing-yield management. Interferometry is a well-known metrology technique that offers low spatial sampling size and the ability to measure a wide area; however, there are some limitations in measuring the thickness of the thin film. This paper proposes a method to calculate the thickness of the thin film in the following two steps: first, pre-estimation of the thickness with the phase at the peak position of the interferogram at the bottom surface of the thin film, using white-light phase-shift interferometry; second, accurate correction of the measurement by fitting the interferogram with the theoretical pattern through the estimated thickness. Feasibility and accuracy of the method has been verified by comparing measured values of photoresist pattern samples, manufactured with the halftone display process, to those measured by AFM. As a result, an area of $880{\times}640$ pixels could be measured in 3 seconds, with a measurement error of less than 12%.

• Food Science and Preservation
• /
• v.13 no.5
• /
• pp.623-628
• /
• 2006

This study was performed to develop extract materials from Elsholtzia splendens by analyzing the functionality and aroma profile by the simultaneous steam distillation extraction. The qualities of extracts such as total yield, total phenolic compound and electron donation ability were affected by extraction temperature than time. The main flavor compounds were analyzed as estragole, thymol and beta-caryophyllene. The response variables had significant with extraction temperature than tim. The established model was suitable to predict calculated value in experimental ranges. The optimum extinction conditions, which were limited of maximum value for dependent variables were $108^{\circ}C$ and 2.1 hr in the simultaneous steam distillation extraction method.

• Korean Journal of Agricultural Science
• /
• v.47 no.3
• /
• pp.577-596
• /
• 2020

Drought is a natural disaster that directly affects agriculture, which has a great impact on the global agricultural production system and yield. The lack of water storage in most parts of the country due to the lack of precipitation has caused a great increase in social interest in drought due to the dryness of rice fields and crops. As the drought period increases and the drought intensity becomes stronger, it is believed that drought damage to crops will continue; thus, it is necessary to understand the vulnerability to irrigation performance and the ability of irrigation facilities. Therefore, this study conducted a vulnerability assessment of irrigation facilities (public Groundwater well) in cities across the country. The survey was conducted using statistical data from 2007 to 2016, and the vulnerability score was calculated according to the vulnerability evaluation procedure for drought in the irrigation facilities (public groundwater wells). Among 157 regions, 136 areas were very vulnerable; 14 areas were vulnerable; 3 areas were normal; 4 areas were good, and 0 areas were excellent. The vulnerability assessment can be used as basic data for the development or maintenance of field irrigation facilities in the future by understanding the vulnerability of irrigation facilities.

• Korean Journal of Materials Research
• /
• v.24 no.1
• /
• pp.13-18
• /
• 2014

In order to clarify the effect of Nb addition on the ductile-brittle transition property of sintered TiC, TiC-10 mol% Nb composites were researched using a three-point bending test at temperatures from room temperature to 2020 K, and the fracture surface was observed by scanning electron microscopy. It was found that the Nb addition decreases the ductile-brittle transition temperature of sintered TiC by 300 K and increases the ductility. The room temperature bending strength was maintained at up to 1800 K, but drastically dropped at higher temperatures in pure TiC. The strength increased moderately to a value of 320MPa at 1600 K in TiC-10 mol% Nb composites, which is 40% of the room temperature strength. Pores were observed in both the grains and the grain boundaries. It can be seen that, as Nb was added, the size of the grain decreased. The ductile-brittle transition temperature in TiC-10 mol% Nb composites was determined to be 1550 K. Above 1970 K, yieldpoint behavior was observed. When the grain boundary and cleavage strengths exceed the yield strength, plastic deformation is observed at about the same stress level in bending as in compression. The effect of Nb addition is discussed from the viewpoint of ability for plastic deformation.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1998.10a
• /
• pp.210-232
• /
• 1998

Tong-il, the high-yielding rice variety bred on early 1970, effected a turning point in modern rice production in Korea. As rice production reached the highest record yield in 1978 with HYV, Korea achieved self-sufficiency in domestic supply of rice (or the first time in (her own) history, HYV required high input of fertilizers and pesticides for proving its yielding ability and needed new techniques such as early nursery-planting to prevent chilling damage. But, farm economy did not follow the successful achievement of rice production because of increased farming cost and inflation.'Tong-il variety has been replaced by new high-yielding Japonica varieties from 1980 when record-low-temperature during summer months had persisted. Also, the cooked rice of Tong-il variety did not agree with the appetite of Korean people. Though the hectarage of Tong-il rice did reduce, farmers applied the same high-input cultural techniques for new Japonica cultivars as did for Tong-il variety. Heavy application of nitrogen fertilizer contaminated surface and ground water with nitrate ions while phosphorous fertilizer was blamed for algae pollution. Frequent spray of pesticide and herbicide reduced significantly the biotic population in paddy ecosystems including insects and soil microorganisms. The new technologies of the 21st century must be directed to produce safe food, to save natural resources, and to preserve a clean environment for human welfare. We need low-input sustainable farming techniques to provide high-yielding crops and to preserve a healthy ecosystem.

• Journal of the Society of Disaster Information
• /
• v.11 no.3
• /
• pp.400-405
• /
• 2015

Operating system of CBRNE(Chemical, Biological, Radiological, Nuclear, and High-yield explosive)) weapon in North Korea has reached an internationally significant level. In preparation against the CBRNE weapon attack, the US is securing various forms of defense shelters and operating it based on classification by disaster characteristics. However, it is currently difficult to expect an efficient protective ability from South Korea due to the reckless designation of defense shelters without consideration of disaster characteristics. At this, this study examined the present condition of formerly used facilities, analyzed the characteristics of each facilities for the sorting of defense shelters that are possible of conversion into shelter against CBRNE weapon, and presented results and proposals gained through this study research.

• Archives of design research
• /
• v.12 no.4
• /
• pp.161-170
• /
• 1999

In recent days, consumer's product selection various with diverse life style, not simply with income class. This in why diversified demand and diversified products appear in every industry, which means the success or failure of business relies on tis ability to yield the best productivity under the condition of diversification. The purpose of this study is to discuss how an automaker can create its unique identity and brand image in automobile industry and what's brand role and value, under the recognition that clarifying a target market in development process is indispensable to developing a product of higher marketability. By building and applying a product of higher marketability. By building and applying a brand-unique consistent design identity, it's intended to meet the increasing requirements of product attribute for symbolism or sensitivity so as satisfy or exceed customer expectation.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.272-272
• /
• 2013

The attractive features of photosynthetic reaction center proteins for energy application make them useful in solar energy conversion to hydrogen fuel or electrical energy. Almost unity charge separation quantum yield and its rapid speed of ~1ns, absorbance region in visible light (480~740 nm) and high proportion of photosynthetically active solar energy of 48.5% allowed photosystem1 to exploited as a bio-material for photo-energy devices. Directionality of photosystem1 in electron transfer can solve main problem in two-step water splitting process where back reaction deteriorates the overall efficiency. In the study, photosystem1 was extracted from spinach and the photo-induced excited electron in the reaction center was utilized in various field of light energy application. First, hydrogen evolving system realized by photodeposition of platinum at the end of the electron transfer chain, with combining specific semiconductor to oxidize water in the first step of Z-scheme. The evaluation by gas-chromatography demonstrated hydrogen evolution through the system. For the further application of photoelectrical material on electrode, photosystem1 have been controlled by copper ion, which is expected to assemble photosystem in specific orientation followed by maximized photoelectrical ability of film. The research proposed concrete methods for combining natural protein and artificial materials in one system and suggested possibility of designing interface between biological and inorganic materials.

• Earthquakes and Structures
• /
• v.13 no.4
• /
• pp.409-419
• /
• 2017

In order to analyze the vibration control effect of viscous damper in the concrete archaized buildings with lintel-column joints under seismic action, 3 specimens were tested under dynamic excitation. Two specimens with viscous damper were defined as the controlled component and one specimen without viscous damper was specified as the non-controlled component. The loading process and failure patterns were obtained from the test results. The failure characteristics, skeleton curves and mechanical behavior such as the load-displacement hysteretic loops, load carrying capacity, degradation of strength and rigidity, ductility and energy dissipation of the joints were analyzed. The results indicate that the load-bearing capacity of the controlled component is significantly higher than that of the non-controlled component. The former component has an average increase of 27.4% in yield load and 22.4% in ultimate load, respectively. Meanwhile, the performance of displacement ductility and the ability of energy dissipation for the controlled component are superior to those of the non-controlled component as well. Compared with non-controlled component, equivalent viscous damping coefficients are improved by 27.3%-30.8%, the average increase is 29.0% at ultimate load for controlled component. All these results reflect that the seismic performance of the controlled component is significantly better than that of the non-controlled component. These researches are helpful for practical application of viscous damper in the concrete archaizing buildings with lintel-column joints.