• Composites Research
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• v.32 no.6
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• pp.368-374
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• 2019

Basalt fiber reinforced epoxy composites with inorganic filler (BFRP-F) such as Mg(OH)₂ (magnesium hydroxide), Al(OH)₃ (aluminum hydroxide), Al₂O₃ (aluminum oxide) and AlOOH (boehmite) were prepared by hand lay-up and hot pressing. The combustive properties of BFRP-F were improved comparing with basalt fiber reinforced epoxy composite (BFRP) without inorganic filler. At a 30 wt% resin content, the limited oxygen index (LOI) of BFRP is 28.9, which is higher than that of epoxy (21.4), and the LOI of BFRP-F is higher than that of BFRP. The BFRP-F showed the lower peak heat release rate (PHRR), total heat release (THR) and total smoke release rate (TSR) than those of BFRP. We confirmed that the flame retardant properties of the composite were improved by the addition of inorganic filler through the dehydration reaction and oxide film formation.

• MALSORI
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• no.21_24
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• pp.111-122
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• 1992

본 논문에서는 한국어에 있어서 세 가지 유형의 파열음과 일본어에 있어서 두 가지 유형의 파열음과 일본어에 있어서 두 가지 유형의 파열음이 보여주는 시간적 특성을 어두 위치 및 모음간 위치로 나누어 비교해 보았다- 한국어에 있어서 세 가지 유형의 파열음은 어두 위치에서 모두 무성음으로 실현되므로 성의 대립으로는 이들을 유형화 할 수 없고, 그보다는 조음의 힘과 기식의 유무에 따라 연음, 무기 경음, 유기 경음으로 분류하는 것이 타당하다. 이에 비해 일본어 파열음은 유성음인 연음과 무성음인 경음의 두가지 유형으로 대립된다. 유성음과 무성음, 그리고 유기음과 무기음의 구분에는 파열음의 개방에서부터 성대 진동까지의 시간인 성 시작 시간(VOT)과 기식의 길이가 변수가 된다. 경음과 연음의 구분에는 선행 모음의 길이, 폐쇄 지속 시간, Vl/(Vl+CL)의 비율이 유용한 정보가 된다. 양국어 어두 파열음의 VOT를 비교해 볼 때, 일본어 유성음은 음수의 VOT를 가지며, 한국어 무기 경음에서는 VOT가 10msec정도로 짧게 나타나고, 그 다음으로 한국어 연음. 일본어 무성음, 한국어 유기 경음의 순서로 길어진다. $\frac{선행 모음의 길이}{(선행 모음의 길이+폐쇄 지속 시간)}$의 비율은 언어의 특성도 반영해 주는데, 한국어의 경우 연음: 무기 경음: 유기 경음의 비는 0.63: 0.30:0.35, 일본어의 경우 유성음:무성음의 비는 0.69: 0.45로 나타났다. 청취 실험을 통해 한국인의 자음 인식 경향을 살펴본 결과, 성대 진동의 유무를 변별적으로 사용하지 않는 한국인 화자는 일본어 유성음은 연음으로, 무성음은 경음으로 인식하는 경향이 있는 것으로 나타났다.

• Korean journal of food and cookery science
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• v.15 no.5
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• pp.545-549
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• 1999

This study was performed to estimate mineral contents of some underground vegetables including potatoes, sweet-potatoes, carrots, radishes, onions, garlics, gingers, burdocks, and lotus roots produced in Korea using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). According to the measurement, the amounts of Na, Mg, Al, K, Ca, Mn, Fe, Zn, and P in underground vegetables are variable depending upon harvest time and individual plants. It was noticeable that the carrots showed quite higher amounts of Na compared to other underground vegetables. The amounts of Cd, Ba, Sr and Pb appeared to be below hazard levels. In the near future we expect that this study can be used to calculate the mineral intake from underground vegetables.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.16-28
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• 2015

In order to elucidate the spatiotemporal variations of marine environmental parameters, we collected seawater samples in the south-western region of the East Sea in May, August, and November 2012 and February 2013. The concentrations of dissolved inorganic nutrients (dissolved inorganic nitrogen, phosphorus, and silicate) in surface seawater during the summer season were lower than those during autumn and winter seasons, which the mixed layer is deeper. The low nutrient concentration in spring and summer seasons seems by consumption of dissolved inorganic nutrients by phytoplankon photosynthesis (high chlorophyll a concentration) and the limited supply of dissolved inorganic nutrients from subsurface layer having high nutrients. The low nutrient concentration during spring season seems to be related to the limited supply of dissolved inorganic nutrients from land and subsurface layer because the concentration of chlorophyll a was low. The DIN:DIP ratio was a wide range of average $15.6{\pm}13.6$ in the surface seawater compared to that of average $14.8{\pm}4.2$ in the bottom seawater during sampling periods. The dissolved inorganic nitrogen might act as a limiting factor of the growth of phytoplankton because the DIN:DIP ratio (on average $8.35{\pm}4.67$) was low during the spring season.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.5
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• pp.19-29
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• 2006

In this study, numerical simulation of airframes separating from a missile system has been preformed. For the time-accurate trajectory simulation, six D.O.F equations of motion of multiply connected bodies were derived and these equations have been coupled with the unstructured overset mesh technique for the treatment of independent mesh blocks moving with each body component. Applications were made for the simulation of the airframe separation at missile angles of attack of 0 and 5 degrees. It was demonstrated that the present method is efficient and robust for the prediction of unsteady time-accurate flow fields involving multiple bodies in relative motion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1270-1276
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• 2013

Laver, a red algae belonging to the genus Porphyra tenera, is one of the most widely consumed edible seaweeds in Korea, China, and Japan. Lavers are usually consumed in dried, roasted, and seasoned forms to improve their palatability. We evaluated the composition of amino acids, minerals, and trace heavy metals in these three differently cooked forms of laver. The moisture and ash contents of three differently cooked lavers ranged from 1.49~9.69% and 6.07~10.31%, respectively. The crude protein and lipid content ranged from 17.24~36.88% and 0.52~42.42%, respectively. Dried laver was found to be a good source of amino acids such as taurine, alanine, and glutamic acid (871.10 mg, 833.53 mg, and 719.77 mg per 100 g dry weight, respectively). Laver was a good source of macro and micro minerals such as K, Ca, Mg, Na, P, I, and Fe, although laver more extensively cooked (roasted and seasoned) contained less minerals compared to the dried form. Mercury levels in the three differently cooked forms of laver were all less than 100 ng/g dry weight (the limit of detection with our methodology). The levels of arsenic were the most abundant elements in the differently cooked laver. There was a clear variation, depending on the cooking process, in terms of amino acid, mineral, and trace metal contents of laver.

• Journal of Nutrition and Health
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• v.48 no.4
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• pp.352-363
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• 2015

Purpose: Despite the popularity of dietary supplements, little data are available on their use by university students. The purpose of this study was to examine the use of vitamin mineral supplements and to identify factors related to supplement use among university students. Methods: University students (N = 345) in Seoul were surveyed. Survey questions included descriptive demographics, types of vitamin and mineral supplements used, health related lifestyle factors, mini dietary assessment, and knowledge and behaviors related to supplement use. Results: Of university students surveyed, 41% consumed vitamin and mineral supplements. Among the supplement users, multivitamins were the most commonly used dietary supplements (68.6%), followed by vitamin C (31.4%) and calcium (17.1%). In particular, the use of vitamin C and iron supplements was more common in females than males (p < 0.05). For the number of supplements taken daily, 32.1% of supplement users consumed 2 or more supplements; 20% of supplement users had almost no knowledge of the supplements being taken. Based on the results of multivariable logistic regression analysis, supplement use was associated with higher interest in their own health, non-smoker, and supplement use by family (p < 0.05). In addition, supplement use was slightly associated with healthy dietary behavior such as consuming a variety of foods (p = 0.05) and current disease status (p = 0.05). Conclusion: University students with relatively healthy lifestyles appear to take vitamin and mineral supplements, but they had little knowledge of the supplements. Given high prevalence of dietary supplement use among university students, nutrition education regarding supplement use is needed.

• Proceedings of the KSCN Conference
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• 2003.05a
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• pp.138-138
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• 2003

흡연은 각종 암의 발병율을 높이고 동맥경화증, 혈전증과 같은 관상심장질환의 주요 발병요인이 되는 것으로 알려져 있다. 흡연자에게 보여지는 지질과산화작용에 의한 LDL의 산화는 구리나 철과 같은 항산과 관련 무기질에 의해 촉진되며, 특히 구리는 매우 연관성이 높은 물질로 보고되었다. 따라서 흡연자의 혈중 무기질 함량의 측정은 항산화 능력과 심혈관계 질병의 진단 및 예후 판정에 민감한 지표로 사용할 수 있을 것으로 사료된다. (중략)

• Defense and Technology
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• no.7 s.137
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• pp.6-19
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• 1990

공산권의 급격한 체제변화에도 불구하고 적화통일의 정책을 버리지 않고 있는 북한과 대치하고 있는 우리로서는 북한의 기술적 기습에 능동적으로 대처하고, 나아가 선진국의 기술예속으로부터 탈피하기 위하여 선별된 분야에서 선진국 수준의 첨단기술을 조기에 확보할수 있도록, 앞으로 국방과학기술에 대한 연구개발정책과 체제를 대폭 강화해야 할 것이다. 이를 위해서는 강력한 국가의 의지와 함께 주요 무기체계는 국내개발로 이룩한다는 정책이 필요하다. 또한 무기획득의 장기계획과 범국가적인 국방과학기술협력체제의 확립이 절실히 요구되며, 연구 개발비의 확대와 각종 제도개선등 기술 개발에 대한 유인책이 필요하다고 본다.

• Defense and Technology
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• no.10 s.248
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• pp.48-53
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• 1999

군사력 건설은 장기간이 소요되므로, 주변국에 비하여 국력은 약하지만 영토 및 무역항로 주변에 항상 분쟁의 소지를 안고 있는 우리로서는 강대국이 보유한 고성능의 모든 무기체계를 다 가지려고 해서는 안 되며, 지금부터라도 비용을 최소화 하면서 주변 강국에 견제세력으로 작용할 무기체계들을 도출하여, 보복력을 발휘할 때까지 적의 선제공격에 어느 정도 지탱할 수 있는 방어 시스템과 더불어 집중연구 개발하여 다가올 21세기에 능동적으로 대비해야 할 것이다