31. Attempts to resolve this dilemma have resulted in the development of

32. Many complex processes unfortunately, do not yield to this design procedure and have, therefore, not yet been automated.

33. Most of the methods developed so far are deterministic and /or probabilistic in nature.

34. The central issue in all these studies is to

35. The problem of xx has been studied by other investigators, however, these studies have been based upon classical statistical approaches.

36. Applied ... techniques to

37. Characterized the ... system as

38. Developed an algorithm to

39. Developed a system called ... which

40. Uses an iterative algorithm to deduce

41. Emphasized the need to

42. Identifies six key issues surrounding high technology

43. A comprehensive study of the... has been undertaken

44. Much work has been reported recently in these filed

45. Proposed/Presented/State that/Described/Illustrated/

Indicated/Has shown / showed/Address/Highlights

46. Point out that the problem of

47. A study on ...was done / developed by []

48. Previous work, such as [] and [], deal only with

49. The approach taken by [] is

50. The system developed by [] consists

51. A paper relevant to this research was published by []

52. []'s model requires consideration of...

53. []' model draws attention to evolution in human development

54. []'s model focuses on...

55. Little research has been conducted in applying ... to

56. The published information that is relevant to this research...

57. This study further shows that

58. Their work is based on the principle of

59. More history of ... can be found in xx et al. [1979].

60. Studies have been completed to established

61. The ...studies indicated that

62. Though application of xx in the filed of xx has proliferated in recent years, effort in analyzing xx, especially xx, is lacking.

Problem / Issue / Question

63. Unfortunately, real-world engineering problems such as manufacturing planning do not fit well with this narrowly defined model. They tend to span broad activities and require consideration of multiple aspects.

64. Remedy / solve / alleviate these problems

67. ... is a difficult problem, yet to be adequately resolved

68. Two major problems have yet to be addressed

69. An unanswered question