• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.140-145
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• 1994

In this paper, we consider a problem to estimate process parameters using input-output data collected from the process operating in closed-loop control system. When orders and delay-time of the process are known correctly, under some conditions of identifying experiments, it is reported that accurate identification results can be obtained by applying prediction error method. To get accurate estimates, it is necessary to know orders and delay-time of the process. It is difficult to determine them in closed-loop identification, because ill-condition for identification are easily caused by selection of unsuitable order or delay time. Furthermore, the procedures to select orders and delay-time in open-loop identification aren't always available in closed-loop identification. The purpose of this paper is to determine a delay-time under suitable assumption that order of the process are known as the first step.

• Current Optics and Photonics
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• v.7 no.3
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• pp.273-282
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• 2023

This paper presents a new method for redistributing effectively the first orders of each lens element to achromatize and athermalize an optical system, by introducing a novel method for adjusting the slope of an achromatic and athermal line. This line is specified by connecting the housing, equivalent single lens, and aberration-corrected point on a glass map composed of available plastic and glass materials for molding. Thus, if a specific lens is replaced with the material characterized by the chromatic and thermal powers of an aberration-corrected point, we obtain an achromatic and athermal system. First, we identify two materials that yield the minimum and maximum slopes of the line from a housing coordinate, which specifies the slope range of the line spanning the available materials on a glass map. Next, redistributing the optical first orders (optical powers and paraxial ray heights) of lens elements by moving the achromatic and athermal line into the available slope range of materials yields a good achromatic and athermal design. Applying this concept to design a mobile-phone camera lens, we efficiently obtain an achromatic and athermal system with cost-effective material selection, over the specified temperature and waveband ranges.

• Journal of Ecology and Environment
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• v.36 no.2
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• pp.125-129
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• 2013

The study on the major insect pests community of Hibiscus syriacus. There were three orders, seven families, and thirteen species of insects harmful to H. syriacus. When the harmful insects eating H. syriacus were classified according to which part of the flower they were eating, insects eating leaves, which considered of nine species four families and one order, accounted for 69.23 %. Insects sucking juice from leaves and stems comprised 15.38 %, with two species two families and two orders, while insects eating seeds comprised 15.38 %, with two species two families and two orders. Aphis gossypii appeared once per H. syriacus from the fourth week of April to the second week of June, appearing the most at a rate of 69.05 per H. syriacus during the first week of May. Dichocrocis surusalis appeared at a rate of 0.05 per H. syriacus during the third week of April and regularly appeared from the first week of July to the second week of September. Nortacha derogata appeared at a rate of 0.1 per tree during the first week of May, after which it continuously appeared until the third week of October. Anomis privata appeared at a rate of 0.05 per tree during the first week of May and continuously occurred from the fourth week of June to the fourth week of October. Its occurrence was most frequent at 2.30 per tree during the third week of September.

• Management Science and Financial Engineering
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• v.14 no.1
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• pp.35-63
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• 2008

We discuss the problem of selecting profitable customer orders arriving at a company providing two classes of services. For an arriving customer order for the first class, the company 1) makes a decision whether to accept or reject it (admission control), or 2) decides a price of the order to offer to an arriving customer (pricing control). The customer order undergoing processing in the system may be cancelled owing to unavoidable circumstances with the customer. The second class of service is provided as a sideline, which prevents the server from being idle when all the customer orders for the first class are completed and delivered. This yields the sideline profit. We discuss both admission control and pricing control problems in an identical framework as well as examine the structure of the optimal policies maximizing the total expected present discounted net profit gained over an infinite planning horizon.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.1
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• pp.63-68
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• 2007

The computations of an ultra-high degree associated Legendre functions and its first derivative up to degree and order of 10800 are reported. Not only the magnitude of orders for the ultra-high degree calculation is presented but the numerical stability and accuracy of the computed values are described in detail. The accuracy on the order of $10^{-25}\;and\;10^{-15}$ was obtained for the values of Legendre function and the first derivatives of Legendre functions, respectively. The computable highest degree and order of Legendre function in terms of latitudes and the linear relationship between the magnitude of the function with respect to degrees and orders is found. It is expected that the computed Legendre functions contribute in many geodetic and geophysical applications for simulations as well as theoretical verifications.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.1
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• pp.109-142
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• 2005

This paper aims to study international political orders and aviational orders since the second World War, to investigate the influences between the two orders, to connect them with the air transportation service agreement between Korea and USA, and to prospect international aviation orders in the future. The first international aviation order after the second World War is built up by international public goods under hegemonic stability theory in the realistic international order. Second order is a kind of cooperation system through the international institutions under the neo-liberalistic international order from the late of 1970s. Third order is the multiple cooperation through the shared epistemology, understanding, and knowledge under the international social constructivism from the 1990s. This paper prospects that international aviation order in the future will be developed through the multiple channels for the civilian users' conveniences and the openness for the users.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.149-154
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• 1991

The one of the important problems in the design of queueing systems is the decision of the order of service stations. The object of this problem is the decision of the order that minimizes the expected sojourn time per customer in the given arrival process and service time distributions. In this paper, the tandem queueing system in series is studied with the emphasis on the optimal order of the tandem queueing system which has three stations with single servers. In one system, customers arrive at the first station with Poisson process. This system is composed of service stations with a constant, a general distribution and a Exponential distribution is studied. To select the optimal order after the orders of each pair of two stations is decided, it is compared the two orders of system. With this results, total expected delay of the systems which has three stations is compared. The result is the best that service station with constant time is on the first place, then the service station with general distribution and the service station with Exponential distribution is followed. And the other system is consist of service stations with a constant and two probabilistic distributions. In this case, two probabilistic distributions has a non-overlapping feature. It is the optimal order that the service station with constant time is on the first place then the service station with longer service time and the service station with shorter service time is followed.

• Management Science and Financial Engineering
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• v.13 no.2
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• pp.47-77
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• 2007

This paper considers a scheduling problem where a customer orders multiple products(jobs) from a production facility. The objective is to minimize the sum of the order(batch) completion times. While a machine can process only one job at a time, multiple machines can simultaneously process jobs in a batch. Although each job has a unique processing time, we consider the case where batch processing times are identical. This simplification allows us to develop heuristics with improved performance bounds. This problem was motivated by a real world problem encountered by foreign electronics manufacturers. We first establish the complexity of the problem. For the two parallel machine case, we introduce two simple but intuitive heuristics, and find their worst case relative error bounds. One bound is tight and the other bound goes to 1 as the number of orders goes to infinity. However, neither heuristic is superior for all instances. We extend one of the heuristics to an arbitrary number of parallel machines. For a fixed number of parallel machines, we find a worst case bound which goes to 1 as the number of orders goes to infinity. Then, a tighter bound is found for the three parallel machine case. Finally, the heuristics are empirically evaluated.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.90-96
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• 2011

In this paper, we propose a new discrete logarithm problem(DLP) based on the class semigroups of imaginary quadratic non-maximal orders using the special character of non-invertible ideal and analysis its security. To do this, we first explain the mathematical background explicitly and prove some properties of Cls (O) which relate to constructing the DLP and guaranteeing the security. To test the security of the proposed DLP, we compare the class number of the maximal order with that of the non-maximal order and investigate the unique factorization problems of ideals between class groups of the maximal orders and class semigroups of non-maximal orders to ensure the security of the cryptosystem.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.289-294
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• 2021

A mushroom survey was conducted in Mt. Cleopatra Needle Forest Reserve (CNFR) northeast of Puerto Pincesa, the capital city of Palawan island, from August 2018 to September 2019. During this period, 433 fungal fruiting bodies were collected from 3 different from survey sites, Concepcion, Kalakwasan, and Tanabag Barangays. The specimens were identified based on their morphological and molecular analyses and classified into 176 species, 114 genera, 55 families, and 22 orders. The mushrooms belong to Ascomycota were classified into 20 species, 15 genera, 12 families, and 7 orders, while those belongs to Basidiomycota were classified into 156 species, 99 genera, 43 families, and 15 orders, respectively. Among these mushrooms, the families with high frequency were Polyporaceae (18.9%), Marasmiaceae (11.5%), Xylariaceae (9.7%), Agaricaceae (8.3%), Auriculariaceae (4.8%), Ganodermataceae (4.2%), Hypoxylaceae (3.2%), and Sarcoscyphaceae (3.0%), and comprised 63.7% of the total specimens identified. This report may be the first checklist of mushrooms in Mt. CNFR and could be used for developing conservation strategies of the critical habitat in Palawan island.